CSA-B64.10 Selection and Installation of Backflow

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Selection and installation of backflow preventers/Maintenance and field testing of backflow preventers

B64.10-07/B64.10.1-07

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Update No. 1 B64.10-07/B64.10.1-07 July 2008
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Note: General Instructions for CSA Standards are now called Updates. Please contact CSA Information Products Sales or visit www.ShopCSA.ca for information about the CSA Standards Update Service. Title: Selection and installation of backflow preventers/Maintenance and field testing of backflow preventers — originally published July 2007 The following revisions have been formally approved and are marked by the symbol delta (Δ) in the margin on the attached replacement pages: Revised New Deleted Figure E.1 None None

CSA B64.10-07/B64.10.1-07 originally consisted of 146 pages (x preliminary and 136 text), each dated July 2007. It now consists of the following pages: July 2007 July 2008 iii–x, 1–60, and 63–136 61 and 62

• Update your copy by inserting these revised pages. • Keep the pages you remove for reference.

July 2008 (Replaces p. 61, July 2007) Item 1 2 Authorized function Carry out crossconnection survey Install, relocate, or replace backflow preventer Repair backflow preventer Test backflow preventer Complete Items 1, 2, 3, and 4 in relation to fire protection systems Complete Items 3 and 4 in relation to lawn sprinkler systems 3 4 5 6

Table 1 Authorized functions list
Municipality of _________________ Bylaw number __________________
Professional engineer with tester’s licence ✓ — Certified engineering technologist with tester’s licence* ✓ — Licensed master plumber with contractor’s and tester’s licence ✓ ✓ Journeyman plumber with tester’s licence† ✓ ✓ Apprentice plumber with tester’s licence‡ — ✓ Fire system sprinkler fitter with a tester’s licence — — Lawn irrigation system installer with tester’s licence — —

✓ ✓ ✓

— — ✓

— — — Selection and installation of backflow preventers

✓

—

✓

*Required to be under the direction of a professional engineer. †Required to be employed by a licensed plumbing contractor or licensed fire sprinkler contractor. ‡Required to be employed by a licensed plumbing contractor and under the direct supervision of a journeyman plumber or master plumber.

Figure E.1 (Concluded)

CSA Standards Update Service B64.10-07/B64.10.1-07 July 2007
Title: Selection and installation of backflow preventers/Maintenance and field testing of backflow preventers Pagination: 146 pages (x preliminary and 136 text), each dated July 2007

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Postal/Zip Code

B64.10-07/B64.10.1-07

ASSOCIATION CANADIENNE DE NORMALISATION BUREAU CENTRAL DE L’INFORMATION 5060, SPECTRUM WAY, BUREAU 100 MISSISSAUGA ON L4W 5N6 CANADA
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CSA Standards

B64.10-07/B64.10.1-07 Selection and installation of backflow preventers/Maintenance and field testing of backflow preventers

Published in July 2007 by Canadian Standards Association A not-for-profit private sector organization 5060 Spectrum Way, Suite 100, Mississauga, Ontario, Canada L4W 5N6 1-800-463-6727 • 416-747-4044

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Selection and installation of backflow preventers/ Maintenance and field testing of backflow preventers

Contents
Technical Committee on Backflow Preventers and Water Pressure Reducing Valves vii Preface ix
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

B64.10-07, Selection and installation of backflow preventers
1 Scope 3 1.1 Application 3 1.2 Exclusions 3 1.3 Terminology 3 1.4 Measurement 3 2 Reference publications 3 3 Definitions, abbreviations, and symbols 4 3.1 Definitions 4 3.2 Abbreviations 9 3.3 Symbols 9 3.3.1 Backflow preventers 9 3.3.2 Vacuum breakers 10 3.3.3 Other symbols 11 4 Backflow prevention methods and devices 12 4.1 Air gap 12 4.1.1 General 12 4.1.2 Hazardous installations 12 4.1.3 Use 12 4.2 Barometric loop 12 4.2.1 General 12 4.2.2 Use 13 4.2.3 Limitations 13 4.3 Mechanical backflow preventers 14 4.3.1 Available types 14 4.3.2 Vacuum breaker backflow preventers — General 15 4.3.3 AVB devices 15 4.3.4 PVB devices 17 4.3.5 SRPVB devices 18 4.3.6 HCVB and HCDVB devices 20 4.3.7 DCAP and DCAPC backflow preventers 21 4.3.8 RP and RPF backflow preventers 24 4.3.9 DCVA and DCVAF backflow preventers 25 4.3.10 DuC and DuCF backflow preventers 27 4.3.11 LFVB devices 27 4.3.12 DuCV backflow preventers 28 4.3.13 SCVAF backflow preventers 29 5 Selection of backflow preventers 29 5.1 General 29 5.2 Categories of hazards 30 5.3 Principal ways of providing protection 30 5.3.1 General 30

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5.3.2 5.3.3 5.3.4 5.4 5.5 5.6 5.7 5.8 5.8.1 5.8.2

Individual protection 31 Zone protection 31 Premises isolation 32 Selection guide 33 Backflow from fire protection systems 34 Backflow from water fill stations 36 Backflow from temporary water services 36 Backflow from irrigation systems 36 Above-ground irrigation systems 36 In-ground irrigation systems 36

6 Installation of backflow preventers and vacuum breakers 37 6.1 General requirements 37 6.1.1 Accessibility 37 6.1.2 Clearances 37 6.1.3 Support and restraint 37 6.1.4 Bypasses 37 6.1.5 Field testing at installation 38 6.1.6 Installation of DCAPC backflow preventers 38 6.1.7 Flushing 38 6.2 Sizing 38 6.3 Working pressures and temperatures 38 6.4 Shut-off valves and test cocks 38 6.5 Strainers 39 6.6 Location 39 6.7 Parallel service 39 6.8 Connections to drains 39 6.9 Thermal expansion 40 6.10 Installation orientation 40 6.11 Enclosures and protection from freezing 40 Annexes A (informative) B (informative) C (informative) D (informative) E (informative)

— — — — —

How backflow can occur 42 Guide to the assessment of hazards 45 Water-hauling equipment and backflow devices 55 Conversion tables 56 Model backflow prevention bylaw 57

Tables 1 — Types of backflow preventers and vacuum breakers and applicable CSA Standards 14 2 — Selection guide for backflow preventers 34 3 — Selection guide for backflow preventers for fire protection systems 35 4 — Clearances, mm 37 Figures 1 — Air gap 12 2 — Barometric loop 13 3 — Typical AVB device 15 4 — Use of AVB devices 16 5 — Typical PVB device 17 6 — Use of PVB devices 18 7 — Typical SRPVB device 19 8 — Use of SRPVB devices 19

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Selection and installation of backflow preventers/ Maintenance and field testing of backflow preventers

9 10 11 12 13 14 15 16 17 18 19 20 21

— — — — — — — — — — — — —

Typical HCVB device 20 Use of HCVB and HCDVB devices 21 Typical DCAP backflow preventer 22 Use of DCAP backflow preventers 22 Typical DCAPC backflow preventer 23 Typical RP backflow preventer 24 Use of RP backflow preventers 25 Typical DCVA backflow preventer 26 Use of DCVA backflow preventers 26 Typical DuC backflow preventer 27 LFVB devices 28 Typical DuCV backflow preventer 29 Typical enclosure 41

B64.10.1-07, Maintenance and field testing of backflow preventers
1 Scope 65 2 Reference publications 65 3 Definitions, abbreviations, and symbols 65 4 Devices to be field tested, frequency, and reporting 66 4.1 Devices to be field tested 66 4.2 Frequency of field testing 66 4.3 Reporting 66 5 School accreditation and tester certification and licensing 69 5.1 School accreditation 69 5.2 Tester certification and re-certification 70 5.3 Tester licensing and registration 70 6 Maintenance 71 6.1 General 71 6.2 RP backflow preventers 71 6.3 DCAPC backflow preventers 71 7 Test gauges and kits 72 7.1 Accuracy 72 7.2 Verification and calibration 72 7.3 Units 72 8 Field test requirements and pass/fail criteria 72 8.1 PVB devices 72 8.1.1 General 72 8.1.2 Air inlet valve 72 8.1.3 Check valve 72 8.1.4 Static line pressure 73 8.2 RP and RPF backflow preventers 73 8.2.1 General 73 8.2.2 Relief valve 73 8.2.3 Check valve 1 73 8.2.4 Check valve 2 74 8.2.5 Static line pressure 74

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8.3 8.3.1 8.3.2 8.3.3 8.3.4 8.4 8.4.1 8.4.2 8.4.3 8.5 8.5.1 8.5.2 8.5.3 8.5.4

DCVA, DCVAF, and SCVAF backflow preventers 74 General 74 Check valve 1 74 Check valve 2 75 Static line pressure 75 HCDVB devices — Manual field test of downstream check valve 76 Test requirement 76 Test set-up 76 Test procedure 77 SRPVB devices 77 General 77 Air inlet valve 77 Check valve 77 Static line pressure 77

Annexes A (informative) — Field testing procedures 78 Tables 1 — Field test requirements for backflow preventers 76 Figures 1(a)— Sample testing and inspection report for DCVA backflow preventers and PVB devices 67 1(b)—Sample testing and inspection report for RP backflow preventers 68 1(c)— Sample testing and inspection report for RP and DCVA backflow preventers and PVB and SRPVB devices 69

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Selection and installation of backflow preventers/ Maintenance and field testing of backflow preventers

Technical Committee on Backflow Preventers and Water Pressure Reducing Valves
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

M. Birks J.W. Green R. Armstrong W. Ball S. Breda C. Caruana R.W. Castle S.L. Cavanaugh D. Dolan W.C. Dunmire W.C. Evans R. Funderburk D. Hanna E. Ho K.S. Hui

The Birks Company, Moffat, Ontario City of Calgary, Calgary, Alberta City of Saint John, Saint John, New Brunswick Woodford Manufacturing Company, Colorado Springs, Colorado, USA Breda & Associates Ltd., Downsview, Ontario CSA International, Toronto, Ontario Honeywell Water Solutions, Warwick, Rhode Island, USA Cavanaugh Consulting, Burbank, California, USA City of Coquitlam, Coquitlam, British Columbia FEBCO, a division of Watts Water Technologies, Inc., St. Pauls, North Carolina, USA British Columbia Institute of Technology, Burnaby, British Columbia Conbraco Industries, Inc., Pageland, South Carolina, USA Ontario Backflow & Plumbing Service Ltd., Oshawa, Ontario IAPMO Research & Testing, Markham, Ontario Ontario Ministry of Municipal Affairs and Housing, Toronto, Ontario

Chair Vice-Chair

Associate

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L. Kendall

Hamilton, Ontario Representing the United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry of the United States and Canada A. Knapp & Associates, Toronto, Ontario Representing the Canadian Copper and Brass Development Association Moen Incorporated, North Olmsted, Ohio, USA Saint-Nicolas, Québec Consumer representative Régie du bâtiment du Québec, Québec, Québec Health Canada, Ottawa, Ontario Halifax Regional Water Commission, Halifax, Nova Scotia Humber College, Toronto, Ontario Wilkins, a Zurn Company, Paso Robles, California, USA Watts Industries (Canada) Inc., Burlington, Ontario Kohler Co., Kohler, Wisconsin, USA Delta Faucet Company, Indianapolis, Indiana, USA Capital Regional District Water Services, Victoria, British Columbia City of Brampton, Brampton, Ontario Alberta Municipal Affairs and Housing, Edmonton, Alberta City of Toronto, Toronto, Ontario Canadian Standards Association, Mississauga, Ontario Project Manager Associate Associate Associate Associate

A. Knapp

N. Kummerlen B. Lagueux M. Légaré F. Lemieux S. MacDonald B. Maddock B. Noll P. Paré S. Rawalpindiwala S. Remedios R. Sochowski C. Spagnuolo R. Tomuschat G. Veltman A.I. Murra

viii

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Selection and installation of backflow preventers/ Maintenance and field testing of backflow preventers

Preface
This volume contains the fifth edition of CSA B64.10, Selection and installation of backflow preventers, and the second edition of CSA B64.10.1, Maintenance and field testing of backflow preventers. CSA B64.10 supersedes the previous editions published in 2001 (under the title Manual for the Selection and Installation of Backflow Prevention Devices), 1994, 1988 (as part of the CAN/CSA-B64 Series), and 1981. CSA B64.10.1 supersedes the previous edition, published in 2001 under the title Manual for the Maintenance and Field Testing of Backflow Prevention Devices. This edition of CSA B64.10 includes the following: (a) new definitions and requirements for (i) zone and area protection; (ii) different classes of fire protection systems; and (iii) spill-resistant pressure vacuum breakers (SRPVB); (b) updated hazard categories; (c) new requirements for the prevention of backflow from water fill stations and for temporary water services; (d) a revised and expanded guide to the assessment of hazards in Annex B, which presents information in two separate tables for greater clarity; and (e) the addition of a model backflow prevention bylaw in the new Annex E. The new edition of CSA B64.10.1 now includes field testing procedures for spill-resistant pressure vacuum breakers and testing procedures using a 5-valve differential pressure gauge. Both Standards have been extensively edited to improve consistency and clarity. The two Standards are intended as a guide for designers of potable water supply and plumbing systems in the selection of the proper type of device, for installers and owners in the installation and maintenance of the devices, and for inspection authorities in the testing of the devices after they have been installed. The Standards provide information on other methods of preventing contamination of potable water by backflow from back siphonage or back pressure. CSA B64.10 and CSA B64.10.1 provide selection criteria, installation and maintenance procedures, and techniques that represent the general state of the art, but should not be construed as all-inclusive, especially where procedures and techniques must be altered to meet special conditions. Where there are problems with a specific installation, it is suggested that the manufacturer of the backflow preventer be consulted. These Standards were prepared by the Technical Committee on Backflow Preventers and Water Pressure Reducing Valves, under the jurisdiction of the Strategic Steering Committee on Plumbing Products and Materials, and have been formally approved by the Technical Committee. They will be submitted to the Standards Council of Canada for approval as National Standards of Canada. July 2007
Notes: (1) Use of the singular does not exclude the plural (and vice versa) when the sense allows. (2) Although the intended primary application of this Standard is stated in its Scope, it is important to note that it remains the responsibility of the users of the Standard to judge its suitability for their particular purpose. (3) This publication was developed by consensus, which is defined by CSA Policy governing standardization — Code of good practice for standardization as “substantial agreement. Consensus implies much more than a simple majority, but not necessarily unanimity”. It is consistent with this definition that a member may be included in the Technical Committee list and yet not be in full agreement with all clauses of this publication. (4) CSA Standards are subject to periodic review, and suggestions for their improvement will be referred to the appropriate committee. (5) All enquiries regarding this Standard, including requests for interpretation, should be addressed to Canadian Standards Association, 5060 Spectrum Way, Suite 100, Mississauga, Ontario, Canada L4W 5N6.

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B64.10-07/B64.10.1-07

Requests for interpretation should (a) define the problem, making reference to the specific clause, and, where appropriate, include an illustrative sketch; (b) provide an explanation of circumstances surrounding the actual field condition; and (c) be phrased where possible to permit a specific “yes” or “no” answer. Committee interpretations are processed in accordance with the CSA Directives and guidelines governing standardization and are published in CSA’s periodical Info Update, which is available on the CSA Web site at www.csa.ca.
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July 2007

CSA Standard

B64.10-07 Selection and installation of backflow preventers

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Selection and installation of backflow preventers

B64.10-07 Selection and installation of backflow preventers
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

1 Scope
1.1 Application
This Standard specifies requirements for the selection and installation of backflow preventers. Additional information on how backflow due to back siphonage and back pressure occurs, and how to select and apply specific devices, is included in Annexes A, B, and C.

1.2 Exclusions 1.2.1
This Standard does not specify requirements for materials, construction, or performance tests of backflow preventers. Such requirements are specified in the CSA B64 Series, in ASME A112.18.1/CSA B125.1, and in CSA B125.3. See Table 1.

1.2.2
This Standard does not specify requirements for maintenance or field testing after the initial installation. Such requirements are specified in CSA B64.10.1.

1.3 Terminology
In CSA Standards, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; “should” is used to express a recommendation or that which is advised but not required; “may” is used to express an option or that which is permissible within the limits of the standard; and “can” is used to express possibility or capability. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.

1.4 Measurement
This Standard is written in SI (metric) units. For conversion tables, see Annex D. Vacuum is expressed in pressure below ambient.

2 Reference publications
This Standard refers to the following publications, and where such reference is made, it shall be to the edition listed below. CSA (Canadian Standards Association) B64 Series-07 Backflow preventers and vacuum breakers

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B64.10-07

B125.3-05 Plumbing fittings ASME/CSA (American Society for Mechanical Engineers/Canadian Standards Association) ASME A112.18.1-2005/CSA B125.1-05 Plumbing supply fittings ASSE (American Society of Sanitary Engineering) 1060-2006 Performance Requirements for Outdoor Enclosures for Fluid Conveying Components CGSB (Canadian General Standards Board) CAN/CGSB-24.3-92 Identification of Piping Systems National Research Council Canada National Building Code of Canada, 2005 National Plumbing Code, 2005

3 Definitions, abbreviations, and symbols
3.1 Definitions
The following definitions apply in this Standard and in CSA B64.10.1: Air break — the unobstructed vertical distance between the lowest point of an indirectly connected waste pipe and the flood level rim of the fixture into which the waste pipe discharges. See Fixture. Air gap — the unobstructed vertical distance through air between the lowest point of the water supply outlet and the flood level rim of the fixture or device into which the outlet discharges. Area protection — protection provided for a section of a piping system with potable and non-potable connections (that may or may not be considered cross-connections) downstream of a backflow preventer. See Zone protection. Auxiliary water supply — any water supply on or available to the premises other than the purveyor’s approved public water supply.
Note: The auxiliary water supply can include water from another purveyor’s public water supply or from any natural source, such as a well, lake, spring, river, stream, or harbour; auxiliary water can also include used water or industrial fluids.

Back pressure — a pressure higher than the supply pressure. Back siphonage — backflow caused by pressure below atmospheric in the supply system. Backflow — a flowing back or reversal of the normal direction of flow. Backflow preventer — a device that prevents backflow. Double check valve (DCVA) — a backflow preventer that consists of two force-loaded, independently acting check valves and two resilient-seated shut-off valves located at each end of the DCVA backflow preventer and is fitted with resilient-seated test cocks. DCVA backflow preventers are designed for use under continuous pressure. Double check valve for fire protection systems (DCVAF) — a DCVA backflow preventer specifically designed for use on fire sprinkler and standpipe systems.

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Selection and installation of backflow preventers

Dual check valve (DuC) — a backflow preventer that consists of two independently acting, force-loaded, soft-seated check valves in series. DuC backflow preventers do not have a relief port or test cocks. They are designed for use under continuous pressure. Dual check valve for fire protection systems (DuCF) — a DuC backflow preventer specifically designed for use on residential fire sprinkler and standpipe systems. Dual check valve with atmospheric port (DCAP) — a backflow preventer that consists of two independently acting check valves separated by an intermediate chamber with an atmospheric port. DCAP backflow preventers are designed for use under continuous pressure.
Note: A chamber pressure higher than the supply pressure is required to open the port when there is a positive pressure on the supply side.

Dual check valve with atmospheric port for carbonators (DCAPC) — a backflow preventer specifically designed for use in carbonated beverage dispensing machines that consists of two independently acting check valves biased to normally closed positions and separated by an intermediate chamber with an atmospheric port. DCAPC backflow preventers are designed for use under continuous pressure.
Note: A chamber pressure higher than the supply pressure is required to open the port when there is a positive pressure on the supply side. An integral strainer at the inlet ensures that debris does not foul the device’s check valves or enter the carbonated beverage dispensing machine.

Dual check valve with intermediate vent (DuCV) — a backflow preventer that consists of two independently acting check valves biased to a closed position. Between the check valves there is an atmospheric vent that is biased to an open position. DuCV backflow preventers are designed for use under continuous pressure. Reduced pressure principle (RP) — a backflow preventer that consists of a mechanically independently acting, hydraulically dependent relief valve located in a chamber between two independently operating, force-loaded check valves. RP backflow preventers are designed for use under continuous pressure.
Note: The intermediate chamber pressure is always lower than the supply pressure when there is a positive pressure on the supply side. RP backflow preventers include resilient-seated test cocks and resilient-seated shut-off valves at each end.

Reduced pressure principle for fire protection systems (RPF) — an RP backflow preventer specifically designed for use on fire sprinkler and standpipe systems. Single check valve for fire protection systems (SCVAF) — a backflow preventer that consists of one force-loaded, independently acting check valve, including resilient-seated shut-off valves located at each end of the SCVAF backflow preventer and fitted with resilient-seated test cocks. SCVAF backflow preventers are designed for use under continuous pressure on fire sprinkler and standpipe systems. Backflow prevention device tester — a person who is certified to test backflow preventers by an accredited organization acceptable to the regulatory authority. Confined space — an enclosed or partially enclosed space that has restricted access and egress and that because of its design, construction, location, atmosphere, and contents or work activity therein, is or can become hazardous to the worker. Critical level (CL) — the level of submergence at which a vacuum breaker ceases to prevent back siphonage. Cross-connection — any actual or potential connection between a potable water system and any source of pollution or contamination.
Note: Bypass arrangements, jumper connections, removable sections, swivel or changeover devices, or any other temporary or permanent connecting arrangements through which backflow can occur are considered cross-connections.

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Cross-connection control program (CCCP) — a program initiated by a regulatory authority to administer and regulate the selection, installation, testing, and maintenance of backflow preventers. Enclosure — an above-ground structure, designed to accommodate a backflow preventer, that incorporates positive drainage to prevent submergence of the backflow preventer, provide security, increase accessibility for testing and repair, and possibly provide freeze protection. Fire protection system (class types) — an assembly of pipes and fittings that conveys water from the water service pipe to the fire sprinkler or standpipe outlets. Class 1 system — a fire protection system that has direct connections only from public water mains, has no pumps, tanks, or reservoirs, and has all sprinkler drains discharging to atmosphere, dry wells, or other safe outlets. Class 2 system — a fire protection system that is the same as a Class 1 system but also includes a booster pump in the connection from the municipal water supply system. Class 3 system — a fire protection system that has direct connections from the municipal potable water supply system, elevated storage tanks (either open or closed), fire pumps taking suction from above-ground covered reservoirs or tanks, and pressure tanks. In Class 3 systems, storage facilities are only filled from, or connected to, the municipal potable water supply system, and the water in the tanks is maintained in a potable condition. Class 3 systems resemble Class 1 systems in all other respects. Class 4 system — a fire protection system that has direct connections from the municipal potable water supply system (similar to Class 1 and Class 2 systems) and an auxiliary water supply dedicated to fire department use and available to the premises, such as an auxiliary supply located within 500 m of the pumper connection. Class 5 system — a fire protection system that has direct connections from the municipal potable water supply system and that is also interconnected with an auxiliary water supply. Class 6 system — a fire protection system that is a combined industrial and fire protection system and is supplied from the municipal potable water supply system only, with or without gravity storage or pump suction tanks. Residential “full flow through” system — a fire protection system that is fully integrated into the potable water supply system to ensure a regular flow of water through all parts of both systems. Residential “partial flow through” system — a fire protection system in which flow (during non-functioning periods of the fire system) only occurs through the main header to a water closet located at the farthest point of the system. Fire service pipe — a pipe that conveys water from a municipal potable water supply system or private water supply system to the inside of a building for the purpose of supplying a fire protection system. Fixture — a device that receives water, waste matter, or both and directs these substances into a sanitary drainage system. Hazard — Minor hazard (MH) — any type of cross-connection or potential cross-connection that involves a substance that constitutes only a nuisance and that results in a reduction in only the aesthetic qualities of the water. This category includes all connections described in Clause 5.1.3.2 involving water that might have been heated or cooled and connections that cannot create a danger to health.

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Selection and installation of backflow preventers

Moderate hazard (MoH) — any minor hazard (MH) connection that has a low probability of becoming a severe hazard. This category includes, but is not limited to, connections involving water where the aesthetic qualities of the water have been reduced and, under certain conditions, can create a danger to health. High or severe hazard (HH) — any type of cross-connection or potential cross-connection described in Clause 5.1.3.2 involving water that has additives or substances that, under any concentration, can create a danger to health.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Horizontal — a plane perpendicular to a plumb line ± 2°. Individual protection — protection provided at the connection to a fixture or appliance. Irrigation — artificial watering of land to sustain plant growth. Irrigation system, above-ground — a system of pipes and valves, installed above grade, that carry water for various irrigation uses: examples include garden and soaker hoses, portable lawn or garden sprinklers, and manually controlled micro/drip irrigation systems. Irrigation system, in-ground — a system of pipes and valves that carry water to various types of sprinklers for distribution over the surface of the soil (piping located underground). Pit — a hole or cavity constructed to house a backflow preventer in the ground, and not capable of being physically entered by a person. Port — an aperture for the passage of a fluid that can allow a connection to be made. Atmospheric port — a port that allows air to enter or water to be discharged. Relief port — a port that discharges water from a relief valve. Vent port — a port that vents water (not from a relief valve). Potable water — water safe for human consumption. Potable water system materials — any material acceptable under the National Plumbing Code or a provincial plumbing code for use in a potable water distribution system. Potable water system materials, not acceptable — any material that is not acceptable under the National Plumbing Code or a provincial plumbing code for use in a potable water distribution system. Premises isolation — protection provided at the entrance to a building or facility. Readily accessible — capable of being reached for operation, renewal, servicing, or inspection, without requiring the climbing over or removal of an obstacle or the use of a portable ladder. Regulatory authority — a federal, provincial, or municipal ministry, department, board, agency, or commission that has responsibility for regulating by statute the use of products, materials, or services. Residential (applied to a building) — intended for residential occupancy as defined in the National Building Code of Canada or a provincial building code. Vacuum breaker — a backflow preventer that prevents backflow from back siphonage, i.e., when pressure upstream of the vacuum breaker falls below atmospheric pressure. Air is only admitted downstream of the device. Atmospheric vacuum breaker (AVB) — a vacuum breaker designed to be under pressure only when water is being drawn from the water supply system and for short, intermittent periods of time.

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Hose connection dual check vacuum breaker (HCDVB) — a vacuum breaker that consists of two independently acting check valves, force-loaded or biased to a closed position. Located between the checks is a means of venting to atmosphere that is force-loaded or biased to an open position. HCDVB devices (a) are designed to be under pressure only when water is being drawn from the system and for short, intermittent periods of time; (b) incorporate a means to manually test the operation of the downstream check valve; and (c) are designed to be used where the back pressure generated by an elevated hose is equivalent to 3 m of head pressure or less.
Note: If there is no flow through the HCDVB device, the check valves are closed and the vent is open.

Hose connection vacuum breaker (HCVB) — a vacuum breaker that consists of a single force-loaded check valve biased to a closed position. Downstream of the check valve is a means of automatically venting to atmosphere that is force-loaded or biased to an open position. HCVB devices are designed to be under pressure only when water is being drawn from the water supply system and for short, intermittent periods of time.
Note: If there is no flow through the HCVB device, the check valve is closed and the vent is open.

Laboratory faucet vacuum breaker (LFVB) — a vacuum breaker that consists of two independently acting check valves force-loaded or biased to a closed position. Between the check valves there is an atmospheric vent that is force-loaded or biased to an open position.
Note: When the laboratory faucet is off, the check valves are closed and the atmospheric vent is open; when the faucet is on, the check valves are open and the atmospheric vent is closed.

Pressure vacuum breaker (PVB) — a vacuum breaker that contains an independently acting check valve force-loaded or biased to a closed position, and an independently operating air inlet valve force-loaded or biased to an open position and located downstream of the check valve. PVB devices are (a) equipped with resilient-seated test cocks and resilient-seated shut-off valves located at each end of the vacuum breaker; and (b) designed for use under continuous pressure. Spill-resistant pressure vacuum breaker (SRPVB) — a vacuum breaker that contains an independently acting check valve force-loaded or biased to a closed position, and an independently operating air inlet valve force-loaded or biased to an open position and located downstream of the check valve. A diaphragm separates the flow from the atmospheric vent. SRPVB devices are equipped with a resilient-seated test cock, a bleeder, and resilient-seated shut-off valves located at each end of the device. SRPVB devices are designed for indoor use under continuous pressure. Vault — a room or space that is constructed to house a backflow preventer and that is capable of being entered by a person. See Confined space. Vertical — a plane parallel to a plumb line ± 2°. Water distribution system — an assembly of pipes, fittings, valves, and appurtenances that conveys water from the water service pipe or private water supply system to water supply outlets, fixtures, appliances, and devices.
Note: In the CSA B64 Series, water distribution systems are also referred to as water systems or water supply systems.

Water service pipe — a pipe that conveys water from a public water main or private water source to the inside of the building. Zone protection — protection provided for sections of a piping system within a building or facility with no potable connections downstream of a backflow preventer. See Area protection.

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Selection and installation of backflow preventers

3.2 Abbreviations
The following abbreviations are used in this Standard and in CSA B64.10.1:
Term Air gap Backflow preventers: Double check valve Double check valve for fire protection systems Dual check valve Dual check valve for fire protection systems Dual check valve with atmospheric port Dual check valve with atmospheric port for carbonators Dual check valve with intermediate vent Reduced pressure principle Reduced pressure principle for fire protection systems Single check valve for fire protection systems Check valve Critical level Cross-connection control program Hazard High or severe hazard Minor hazard Moderate hazard Thermal expansion relief (valve) Vacuum breakers: Atmospheric Hose connection Hose connection dual check Laboratory faucet Pressure Spill-resistant pressure Abbreviation AG DCVA DCVAF DuC DuCF DCAP DCAPC DuCV RP RPF SCVAF CV CL CCCP HH MH MoH TER AVB HCVB HCDVB LFVB PVB SRPVB

3.3 Symbols 3.3.1 Backflow preventers
The following symbols for backflow preventers are used in this Standard and in CSA B64.10.1: (a) Double check valve (DCVA)

(b) Dual check valve (DuC)

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(d) Dual check valve with atmospheric port for carbonators (DCAPC)
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(e) Dual check valve with intermediate vent (DuCV)

(f)

Reduced pressure principle (RP)

(g) Single check valve for fire protection systems (SCVAF)

3.3.2 Vacuum breakers
The following symbols for vacuum breakers are used in this Standard and in CSA B64.10.1: (a) Atmospheric vacuum breaker (AVB)

(b) Hose connection dual check vacuum breaker (HCDVB)

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Selection and installation of backflow preventers

(d) Laboratory faucet vacuum breaker (LFVB)
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(e) Pressure vacuum breaker (PVB)

(f)

Spill-resistant pressure vacuum breaker (SRPVB)

3.3.3 Other symbols
The following symbols are used in this Standard and in CSA B64.10.1: (a) Check valve (CV)

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(b) Shut-off valve

4 Backflow prevention methods and devices
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4.1 Air gap 4.1.1 General
Air gaps shall be installed in accordance with the local plumbing or building code to permit atmospheric air, instead of a contaminated or polluted liquid, to enter the potable water system.
Note: In theory, a well-designed and properly maintained air gap is the best means available for protection against backflow. However, an air gap is not always practical and is vulnerable to bypass arrangements that can nullify its effectiveness.

4.1.2 Hazardous installations
In extremely hazardous installations, an air gap separation is recommended.

4.1.3 Use
The proper use of an air gap shall be as illustrated in Figure 1 (see Clause 6.6.1).
Water supply Air gap Supply valve

Flood level rim

Fixture

Figure 1 Air gap
(See Clause 4.1.3.)

4.2 Barometric loop 4.2.1 General
A barometric loop is a piping arrangement designed to make use of the principle that a vacuum can only lift water approximately 10 m against atmospheric pressure. The piping arrangement shall be formed by constructing a loop in the service line that rises 10.7 m or more above the service line, or 10.7 m or more above the highest fixture or device being served. See Figure 2.

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Selection and installation of backflow preventers

Barometric loop 10.7 m

Meter Irrigation system Water main

Water service pipe Meter

Water main

10.7 m Water service pipe Barometric loop

Irrigation system

Figure 2 Barometric loop
(See Clause 4.2.1.)

4.2.2 Use
A properly installed barometric loop is effective against back siphonage only. If there is any possibility of back pressure, a backflow preventer suitable for back pressure type backflow shall be used.

4.2.3 Limitations
The barometric loop is not recommended for backflow prevention because it is difficult to protect it from freezing, and bypasses nullify its effectiveness. A barometric loop shall not be installed without the approval of the regulatory authority.

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4.3 Mechanical backflow preventers 4.3.1 Available types 4.3.1.1 General
The types of mechanical backflow preventers that shall be used for cross-connection control are listed in Table 1.
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Table 1 Types of backflow preventers and vacuum breakers and applicable CSA Standards
(See Clauses 1.2, 4.3.1.1, and 4.3.6.2.)
Applicable CSA Standard B64.1.1 B64.1.2 B64.1.3 B64.2 B64.2.1 B64.2.1.1 B64.2.2 B64.3 B64.3.1 B64.4 B64.4.1 B64.5 B64.5.1 B64.6 B64.6.1 B64.7 B64.8 B64.9

Type Atmospheric vacuum breaker Pressure vacuum breaker Spill-resistant pressure vacuum breaker Hose connection vacuum breaker Hose connection vacuum breaker with manual draining feature Hose connection dual check vacuum breaker Hose connection vacuum breaker with automatic draining feature Dual check valve backflow preventer with atmospheric port Dual check valve backflow preventer with atmospheric port for carbonators Reduced pressure principle backflow preventer Reduced pressure principle backflow preventer for fire protection systems Double check valve backflow preventer Double check valve backflow preventer for fire protection systems Dual check valve backflow preventer Dual check valve backflow preventer for fire protection systems Laboratory faucet vacuum breaker Dual check valve backflow preventer with intermediate vent Single check valve backflow preventer for fire protection systems

Abbreviation AVB PVB SRPVB HCVB

HCDVB

DCAP DCAPC RP RPF DCVA DCVAF DuC DuCF LFVB DuCV SCVAF

4.3.1.2 Plumbing supply fittings
Where a plumbing supply fitting requires backflow protection, it shall be provided in accordance with ASME A112.18.1/CSA B125.1 or CSA B125.3 or be equipped with a backflow preventer in accordance with the CSA B64 Series.

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Selection and installation of backflow preventers

4.3.2 Vacuum breaker backflow preventers — General
Backflow preventers that provide protection from back siphonage are referred to as vacuum breakers. Currently available vacuum breakers usually contain a check valve that prevents backflow and also prevents the entrance of air upstream of the vacuum breaker. If a suction pressure develops upstream of the vacuum breaker, this pressure is equalized by air entering through the atmospheric vents. In the case of atmospheric and hose connection vacuum breakers, when a slight positive differential pressure occurs downstream of the vacuum breaker, water spills out of the atmospheric vent. Although these vacuum breakers do contain check valves, they are not intended to withstand back pressure caused by thermal or mechanical means.

4.3.3 AVB devices 4.3.3.1 General
AVB devices contain a valve that acts as a check valve against back siphonage when the supply pressure drops to atmospheric pressure or lower. When the valve opens the atmospheric vent, it allows air to enter and equalize the pressure. The check valve also seals the atmospheric vent under normal flow conditions (see Figure 3). AVB devices are intended only to prevent back siphonage and not backflow due to back pressure, even though a check valve is present.
Shield

Atmospheric vent Seat Check valve Stop Outlet

Inlet

Figure 3 Typical AVB device
(See Clause 4.3.3.1.)

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4.3.3.2 Use
AVB devices are used to isolate minor or moderate hazards (see Figure 4). If used for severe hazards, zone or area protection shall also be used (see Clause 5).
Water supply AVB device Critical level of the AVB device See applicable plumbing code and Clause 4.3.3.4 for minimum distance

Figure 4 Use of AVB devices
(See Clause 4.3.3.2.)

4.3.3.3 Limitations 4.3.3.3.1
AVB devices do not provide adequate backflow protection when (a) back pressure can be developed on the downstream side of the device; (b) the device is located in an area subject to flooding; and (c) the device is under line flow pressure continuously for more than 12 h.
Note: Codes recognize Item (a) by requiring that atmospheric vacuum breakers be located downstream of the last valve in the water supply system, and Item (b) by requiring that the critical level of a back siphonage preventer be located above the flood level rim of the fixture. See Clause 4.3.3.4.

4.3.3.3.2
When water flows through an AVB device for long periods of time (12 h or more), the check valve can become stuck in the open position, thus rendering the device inoperative as a back siphonage preventer. Therefore, another type of device, such as a pressure type vacuum breaker (PVB) or a reduced pressure principle type backflow preventer (RP), shall be used whenever extended periods of flow could occur.

4.3.3.4 Critical level
AVB devices shall be installed with their critical level at least 25 mm above the flood level rim of the fixture, container, or appurtenance. When the critical level is not marked on an AVB device, the critical level shall be taken as the lowest point on the device.

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Selection and installation of backflow preventers

4.3.4 PVB devices 4.3.4.1 General
PVB devices (see Figure 5) are similar to AVB devices, except that PVB devices can be subject to continuous full line static pressure. The check valve in a PVB device is force-loaded to the closed position, usually by a spring, while the air inlet valve is usually float-operated. The check valve is not intended to resist back pressure caused by thermal or mechanical means. PVB devices are normally available in sizes NPS-2 and smaller.
Shield

Test cock 2

Atmospheric vent

Air inlet valve Check valve Test cock 1
Outlet

Shut-off valve 2

Shut-off valve 1

Inlet

Figure 5 Typical PVB device
(See Clause 4.3.4.1.)

4.3.4.2 Use
PVB devices are used to isolate minor, moderate, or severe hazards (see Figure 6). Careful consideration shall be given to the possibility of improper use of a PVB device, e.g., when a downstream connection is made that would permit back pressure to occur. (See Clause 5.)

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Water supply

PVB device

Critical level of the PVB device See applicable plumbing code and Clause 4.3.4.3 for minimum distance

Figure 6 Use of PVB devices
(See Clause 4.3.4.2.)

4.3.4.3 Critical level
PVB devices shall be installed with their critical level at least 300 mm above the flood level of the fixture, container, or appurtenance. When the critical level is not marked on a PVB device, the critical level shall be taken as the lowest point on the device.

4.3.5 SRPVB devices 4.3.5.1 General
SRPVB devices (see Figure 7) are similar to PVB devices, except that they include a spill-resistant membrane. The check valve in SRPVB devices is force-loaded to the closed position, usually by a spring, while the air inlet valve is float-operated and force-loaded to the open position. The check valve is not intended to resist back pressure caused by thermal or mechanical means. One test cock and one bleeder are provided for periodic testing.

4.3.5.2 Use
SRPVB devices are used to isolate minor, moderate, or severe hazards (see Figure 8). Careful consideration shall be given to the possibility of improper use of SRPVB devices, e.g., when a downstream connection is made that would permit back pressure to occur. (See Clause 5.)

July 2007

Selection and installation of backflow preventers

Shield Atmospheric vent Air inlet valve Bleeder
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Membrane (not shown) Outlet Test cock

Shut-off valve 2

Check valve

Shut-off valve 1 Inlet

Figure 7 Typical SRPVB device
(See Clause 4.3.5.1.)

SRPVB device Critical level of the SRPVB device See applicable plumbing code and Clause 4.3.5.3 for minimum distance Water supply

Figure 8 Use of SRPVB devices
(See Clause 4.3.5.2.)

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4.3.5.3 Critical level
SRPVB devices shall be installed with their critical level at least 300 mm above the flood level of the fixture, container, or appurtenance. When the critical level is not marked on an SRPVB device, the critical level shall be taken as the lowest point on the device.

4.3.6 HCVB and HCDVB devices
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4.3.6.1 General
HCVB and HCDVB devices (see Figure 9) are subgroups of AVB devices and (a) are intended to be installed on the discharge side of a shut-off valve; (b) are designed so that when the shut-off valve is turned off, the check valve closes, opening the atmospheric vent and allowing air into the downstream; (c) incorporate a check valve that is force-loaded to the closed position; and (d) incorporate a vent to atmosphere on the outlet side of the check valve that is force-loaded or biased to the open position.
Inlet Spring

Check valve Vent valve

Atmospheric vent Outlet

Figure 9 Typical HCVB device
(See Clause 4.3.6.1.)

4.3.6.2 HCVB devices
HCVB devices are specifically intended for minor hazard installations such as on a hose bibb to which a garden hose can be attached (see Figure 10). If used for moderate or severe hazards, zone or area protection shall also be used (see Clause 5.4). HCVB devices shall be installed so that the atmospheric vents cannot be submerged in water (see Figure 10).
Notes: (1) HCVB devices are intended to withstand the small amount of back pressure that can occur if the end of the hose is higher than the hose bibb when it is shut off. Some leakage may occur when the hose bibb is first opened. (2) HCVB devices that can be drained to prevent damage to the shut-off valve under freezing conditions are available (see Table 1).

July 2007

Selection and installation of backflow preventers

Install HCVB or HCDVB device at this point Grade
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Building

Hose Water supply Swimming pool

Figure 10 Use of HCVB and HCDVB devices
(See Clause 4.3.6.2.)

4.3.6.3 HCDVB devices
HCDVB devices incorporate a means to conduct a field test to verify the operation of its downstream check valve.

4.3.7 DCAP and DCAPC backflow preventers 4.3.7.1 DCAP backflow preventers 4.3.7.1.1 General
DCAP backflow preventers consist of two independently acting, internally loaded check valves and an intermediate atmospheric port (see Figure 11). The check valves are force-loaded to a closed position and the atmospheric port is force-loaded to an open position. During normal operation, the atmospheric port is closed by the deflection of a diaphragm seal. During backflow conditions, the diaphragm seal is displaced, allowing air to enter the area between the check valves or leakage from the downstream check valve to be discharged to the atmosphere. DCAP backflow preventers are not equipped with test cocks.

4.3.7.1.2 Use
DCAP backflow preventers are intended to prevent backflow due to back siphonage and back pressure where a minor hazard exists (see Figure 12), such as with a low-pressure, single-family residential heating boiler (where no chemical additives are used). If used for moderate hazards, zone or area protection shall also be used (see Clause 5.4).

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Inlet

Primary check valve
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Air inlet valve

Secondary check valve

Atmospheric port

Outlet

Figure 11 Typical DCAP backflow preventer
(See Clause 4.3.7.1.1.)

Low-pressure boiler — single-family residential (no inhibitors added) DCAP Water supply To domestic hot water system — single-family residential

Air gap

Figure 12 Use of DCAP backflow preventers
(See Clause 4.3.7.1.2.)

4.3.7.1.3 Limitation
Because DCAP backflow preventers have no test cocks and are not intended for protection from severe hazards, they shall not be used in place of reduced pressure principle (RP) backflow preventers.

July 2007

Selection and installation of backflow preventers

4.3.7.2 DCAPC backflow preventers
DCAP backflow preventers for carbonators (DCAPC) consist of two independently acting check valves that are normally biased in the closed position. An atmospheric port is located between the check valves (see Figure 13). DCAPC backflow preventers are intended to provide backflow protection when installed on the water supply connection of carbonated beverage dispensing equipment. In the event of a downstream (secondary) check valve failure, with back pressure exceeding supply pressure, the atmospheric port will discharge and visually indicate failure. Under static (non-flowing) conditions, the check valves remain in the closed position. When a valve is opened downstream (i.e., a drink is delivered from the carbonator), the check valves open and permit water flow. Under backflow conditions, the diaphragm seat on the primary check valve lifts and vents flow through the atmospheric port, thus protecting the potable water supply. Under normal operation, the atmospheric port does not discharge.
Inlet Primary check valve

Screen

Atmospheric port

Secondary check valve

Outlet

Figure 13 Typical DCAPC backflow preventer
(See Clause 4.3.7.2.)

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4.3.8 RP and RPF backflow preventers 4.3.8.1 General
RP backflow preventers consist of two independently acting, internally loaded check valves separated by a reduced pressure zone (see Figure 14). During normal operation, the pressure between the two check valves is maintained at a lower pressure than the supply pressure. If either check valve leaks, a relief valve maintains a differential of not less than 14 kPa between the supply pressure and the reduced pressure zone by discharging water through the relief port. Such an occurrence indicates that maintenance is required. Test cocks are provided for periodic testing.

Test cock 3

Reduced pressure zone Test cock 4

Inlet

Test cock 1 Check valve 2 Check valve 1 Shut-off valve 1 Relief port Shut-off valve 2 Differential pressure relief valve

Outlet

Test cock 2

Figure 14 Typical RP backflow preventer
(See Clause 4.3.8.1.)

4.3.8.2 Use
RP backflow preventers (a) are intended to isolate severe hazards (see Clause 5); (b) provide reliable protection from both back siphonage and back pressure (see Figure 15); and (c) are generally used in locations where an air gap is impractical.
Note: One advantage of RP backflow preventers is the visible leakage from the relief port in some instances of failure.

July 2007

Selection and installation of backflow preventers

RP backflow preventer City water supply Air gap Domestic water distribution system Open tank or pressure vessel containing a toxic chemical

(a) Back siphonage protection

City water supply or domestic water distribution system

RP backflow preventer

Irrigation system

Air gap CV Pump Fertilizer

(b) Back pressure protection

Figure 15 Use of RP backflow preventers
(See Clause 4.3.8.2.)

4.3.8.3 RPF backflow preventers
RPF backflow preventers are used to prevent backflow due to both back siphonage and back pressure from fire protection systems where a severe hazard exists (see Clause 5.5).

4.3.9 DCVA and DCVAF backflow preventers 4.3.9.1 General
DCVA backflow preventers consist of two internally loaded check valves, either force-loaded or internally weighted (see Figure 16). With the two check valves in series, the devices prevent backflow even if one check valve fails to close tight, but no visible warning is given of this failure. Test cocks are provided for periodic testing.

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Shut-off valve 1 Test cock 3

Test cock 4

Shut-off valve 2

Test cock 2
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Check valve 1

Check valve 2

Test cock 1 Inlet Disc Seats Disc Outlet

Figure 16 Typical DCVA backflow preventer
(See Clause 4.3.9.1.)

4.3.9.2 Use
DCVA backflow preventers are used to prevent backflow due to both back siphonage and back pressure where a minor or moderate hazard exists (see Figure 17).
DCVA backflow preventer Water supply Open tank

Tank under pressure

Tanks determined to be a minor or moderate hazard

Figure 17 Use of DCVA backflow preventers
(See Clause 4.3.9.2.)

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Selection and installation of backflow preventers

4.3.9.3 DCVAF backflow preventers
DCVAF backflow preventers are used to prevent backflow due to both back siphonage and back pressure from fire protection systems where a minor or moderate hazard exists (see Clause 5.5).

4.3.10 DuC and DuCF backflow preventers 4.3.10.1 General
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DuC backflow preventers consist of two independently acting, internally loaded check valves in series. The device prevents backflow if one check valve fails, but no visible warning is given of this failure. Test cocks are not provided (see Figure 18).
Inlet

Primary check valve

Secondary check valve

Outlet

Figure 18 Typical DuC backflow preventer
(See Clause 4.3.10.1.)

4.3.10.2 Use
DuC backflow preventers are used to prevent backflow due to both back siphonage and back pressure, where a minor hazard exists, and are intended to be used on residential supply services or individual outlets.

4.3.10.3 DuCF backflow preventers
DuCF backflow preventers are used to prevent backflow due to both back siphonage and back pressure from fire protection systems where a minor hazard exists (see Clause 5.5).

4.3.11 LFVB devices 4.3.11.1 General
LFVB devices consist of two independently acting force-loaded check valves. The space between the check valves is vented to atmosphere. The check valves are biased to the closed position and the atmospheric vent is biased to the open position. Test cocks are not provided (see Figure 19).

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4.3.11.2 Use
LFVB devices are (a) intended for use on laboratory faucets; (b) intended for use on the discharge side of the last control valve; and (c) used for minor hazards. If used for moderate or severe hazards, zone or area protection shall also be used. (See Clause 5.4.) LFVB devices shall not be used under continuous pressure conditions (see Figure 19).
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Inlet

LFVB device

Primary check valve Atmospheric vent Secondary check valve

Aspirator Faucet

Outlet

(a) Typical LFVB device

(b) Use of LFVB devices

Figure 19 LFVB devices
(See Clause 4.3.11.1.)

4.3.12 DuCV backflow preventers 4.3.12.1 General
DuCV backflow preventers consist of two independently acting, internally loaded check valves and an intermediate vent to atmosphere. The check valves are biased to the closed position and the atmospheric vent is biased to the open position. DuCV backflow preventers are intended for use under continuous pressure. No test cocks are provided (see Figure 20).

4.3.12.2 Use
DuCV backflow preventers are (a) intended for use on individual outlets or appliances with flow rates of less than 0.25 L/s; and (b) used to prevent backflow due to both back pressure and back siphonage where a minor hazard exists. If used for moderate hazards, zone or area protection shall also be used (see Clause 5.4).

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Selection and installation of backflow preventers

Inlet

Primary check valve Atmospheric vent Secondary check valve

Outlet

Figure 20 Typical DuCV backflow preventer
(See Clause 4.3.12.1.)

4.3.13 SCVAF backflow preventers 4.3.13.1 General
SCVAF backflow preventers consist of one independently acting, internally loaded check valve. No visible warning is given of failure of the check valve to close tight. Inlet and outlet shut-offs and test cocks are provided for periodic testing.

4.3.13.2 Use
SCVAF backflow preventers are used to prevent backflow due to both back siphonage and back pressure from fire protection systems where a minor hazard exists (see Clause 5.5).

5 Selection of backflow preventers
5.1 General 5.1.1
Plumbing codes mandate that the potable water system be protected from backflow. The principal method of protection adopted by plumbing codes is the mandatory provision of an air gap at the supply to the fixture. When an air gap is not provided, a backflow preventer shall be used.

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5.1.2
In buildings, interconnections can easily be made between the potable water supply and any fixture, appliance, system, or non-potable water supply. Such connections are defined as cross-connections and backflow preventers shall be used.

5.1.3
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5.1.3.1
Connections to potable water systems shall be designed so that substances that may render the water non-potable, or change the quality of the water in other respects, cannot enter the potable water system. Where there is an identifiable risk of contamination of a potable water system, preventive measures shall be taken.

5.1.3.2
Connections shall be divided into the following two categories: (a) atmospheric connections — connections that have a pressure that is at, or below, atmospheric pressure; and (b) pressure connections — connections that have a pressure that is greater than atmospheric pressure.

5.1.4
To determine whether protection is necessary, the following shall be identified: (a) the probability that back siphonage will cause backflow; (b) the probability that back pressure will cause backflow; (c) the severity of hazard; and (d) the type of building.

5.1.5
A suitable backflow preventer shall be selected based on (a) a good knowledge of available devices; (b) an understanding of the protection that each device provides; and (c) maintenance requirements of the devices.

5.2 Categories of hazards
Hazards shall be divided into three categories — minor hazard (MH), moderate hazard (MoH), and high or severe hazard (HH). (See the definition of “hazard” in Clause 3.1.)
Note: This Clause addresses the assessment of the potential hazard and the probability that backflow could occur. There is no simple method to quantify the problem by assessing the relevant factors, nor can the backflow preventers be categorized numerically according to the degree of protection they provide.

5.3 Principal ways of providing protection 5.3.1 General 5.3.1.1
To provide complete protection for the potable water supply and the consumer’s potable water system within the premises, backflow protection shall be provided based on a review of the drawings of the proposed piping layout or a survey of the premises. The type of backflow protection shall be selected in accordance with (a) Clause 5.2 (the degree of hazard); (b) Clauses 5.3.1.2 to 5.3.1.4; (c) Clauses 5.3.2 to 5.3.4; (d) Clause 5.4 and Table 2; and (e) Clause 5.5 and Table 3.

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Selection and installation of backflow preventers

5.3.1.2
Premises isolation shall be provided by the installation of an RP backflow preventer on all water systems where a potentially severe hazard may be caused by backflow. The hazard shall be determined based on the type of occupancy or a survey of the premises. Examples of hazard classification are given in Clause 5.3.4.5 and Table B.2.

5.3.1.3
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Premises isolation for all other water services shall be provided when required by a cross-connection control program (CCCP).
Note: The regulatory authority generally enforces a CCCP through the enactment of a bylaw. See the model bylaw in Annex E.

5.3.1.4
Additional protection by one or all of the following means shall also be required as determined by the survey of the premises: (a) individual protection; (b) zone protection; and (c) area protection.
Note: Determining the proper backflow preventer is a subjective matter. Annex B is based on experience and is intended for reference only. Consult your local cross-connection control authority for acceptable standards within your jurisdiction.

5.3.2 Individual protection 5.3.2.1
Individual protection against back siphonage shall be provided by any of the following: (a) an air gap; (b) an AVB device; (c) an HCDVB device; (d) an HCVB device; (e) a PVB device; (f) an SRPVB device; or (g) any device listed in Clause 5.3.2.2.

5.3.2.2
Protection from back pressure type backflow shall be provided by any of the following: (a) DuC backflow preventer; (b) DCAP backflow preventer; (c) DuCV backflow preventer; (d) DCVA backflow preventer; (e) RP backflow preventer; or (f) an air gap.

5.3.2.3
An air gap does not guarantee continuous protection, as it can easily be bypassed. However, an air gap shall remain the first choice to eliminate backflow and shall be inspected, if used on a high hazard, in the yearly testing program for backflow preventers (see Clause 4.1 of CSA B64.10.1).

5.3.3 Zone protection
When zone protection is provided, isolated non-potable water systems shall be clearly identified as required by CAN/CGSB-24.3.

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5.3.4 Premises isolation 5.3.4.1
When required by Clause 5.3.1.2 or 5.3.1.3, premises isolation for a building shall be provided even if the water distribution system in the building complies with current plumbing or building code requirements, because backflow into the potable water system can still occur if the individual protection fails.
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5.3.4.2
Three levels of protection shall be recognized for premises isolation, as follows: (a) Premises with a minor hazard classification shall be isolated with a DuC backflow preventer. This requirement shall not apply to residential premises if no hazards are present. Examples of this hazard classification are given in Clause 5.3.4.3 and Table B.2. (b) Premises with a moderate hazard classification shall be isolated with a DCVA backflow preventer. Examples of this hazard classification are given in Clause 5.3.4.4 and Table B.2. (c) Premises with a severe hazard classification shall be isolated with an RP backflow preventer. Examples of this hazard classification are given in Clause 5.3.4.5 and Table B.2.

5.3.4.3
Buildings or facilities that shall be isolated from the potable water supply by a DuC backflow preventer include the following: (a) residential premises with access to an auxiliary water supply (not directly connected); (b) residential premises serving fewer than four dwelling units with single water service; and (c) buildings with minor hazard classification.
Note: This is not an all-inclusive list; see Table B.2 for additional examples.

5.3.4.4
Buildings or facilities that shall be isolated from the potable water supply by a DCVA backflow preventer include the following: (a) buildings with moderate hazard classification; (b) pleasure-boat marinas; (c) apartment or office buildings; (d) multi-service interconnected facilities; (e) schools and colleges; (f) multi-tenant single-service facilities; and (g) shopping malls.
Note: This is not an all-inclusive list; see Table B.2 for additional examples.

5.3.4.5
Buildings or facilities that shall be isolated from the potable water supply by an RP backflow preventer include the following: (a) chemical or plating plants; (b) commercial laundries; (c) dockside facilities for ships; (d) food and beverage processing plants; (e) hospital, operating, laboratory, or mortuary facilities; (f) petroleum processing and storage facilities; (g) plants using radioactive material; (h) premises where access is restricted; (i) trackside facilities for trains; (j) sewage treatment plants; and (k) steam plants.
Note: This is not an all-inclusive list; see Table B.2 for additional examples.

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Selection and installation of backflow preventers

5.4 Selection guide 5.4.1
The type of backflow preventer to be used for individual protection shall be selected in accordance with Table 2, and the degree of hazard shall be assessed in accordance with Clause 5.2 and Table B.1. For fire protection systems, refer to Clause 5.5 and Table 3.
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5.4.2
Zone or area protection provided by a DCVA backflow preventer, an RP backflow preventer, or an air gap shall be required when any one of the following backflow preventers is used for individual protection of a moderate hazard (MoH): (a) HCVB or HCDVB devices; (b) DCAP backflow preventers; (c) LFVB devices; or (d) DuCV backflow preventers.

5.4.3
Zone protection provided by an RP backflow preventer or an air gap shall be required when any one of the following backflow preventers is used for individual protection of a high or severe hazard (HH): (a) AVB devices; (b) HCVB or HCDVB devices; or (c) LFVB devices.

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Table 2 Selection guide for backflow preventers
(See Clauses 5.3.1.1 and 5.4.1.)
Degree of hazard Type of device Air gap AVB DCAP DCAPC DCVA DuC DuCV HCDVB HCVB LFVB PVB RP SRPVB CSA Standard designation — B64.1.1 B64.3 B64.3.1 B64.5 B64.6 B64.8 B64.2.1.1 B64.2 B64.7 B64.1.2 B64.4 B64.1.3 Device under continuous pressure No No Yes Yes Yes Yes Yes No No No Yes Yes Yes

Minor ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓

Moderate ✓ ✓ ✓† ✓ ✓ — ✓† ✓† ✓† ✓† ✓ ✓ ✓

Severe ✓ ✓* — — — — — ✓* ✓* ✓* ✓ ✓ ✓

*When the recommended backflow preventer is used for this degree of hazard, zone protection with an RP backflow preventer or an air gap shall also be required. †When the recommended device is used for this degree of hazard, zone or area protection with a DCVA backflow preventer, RP backflow preventer, or an air gap shall also be required.

5.5 Backflow from fire protection systems 5.5.1
Residential “full flow through” fire protection systems in which pipe and fittings are made of materials acceptable for potable water systems shall not require a backflow preventer.

5.5.2
Potable water connections to fire protection systems (standpipe and sprinkler systems) shall be protected against backflow caused by back siphonage or back pressure in accordance with the following (see Table 3): (a) Residential “partial flow through” fire protection systems in which the pipe and fittings are made of materials acceptable for potable water systems shall be protected by (i) a DuC backflow preventer complying with CSA B64.6; or (ii) a DuCF backflow preventer complying with CSA B64.6.1. (b) Class 1 fire protection systems that use no antifreeze or other additives of any kind and in which all pipes and fittings are made of materials acceptable for potable water systems shall be protected by (i) an SCVAF backflow preventer complying with CSA B64.9; or

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Selection and installation of backflow preventers

(ii) a DCVA backflow preventer complying with CSA B64.5. (c) Class 1 systems not covered by Item (b), Class 2, and Class 3 fire protection systems that use no antifreeze or other additives of any kind shall be protected by (i) a DCVA backflow preventer complying with CSA B64.5; or (ii) a DCVAF backflow preventer complying with CSA B64.5.1. (d) Class 1, Class 2, or Class 3 fire protection systems in which antifreeze or other additives are used shall be protected (i) by an RP backflow preventer complying with CSA B64.4 or an RPF backflow preventer complying with CSA B64.4.1, on the portion of the fire protection system with the additives; and (ii) in accordance with Item (b) or (c), on the balance of the fire protection system. (e) Class 4 and Class 5 fire protection systems shall be protected by (i) an RP backflow preventer complying with CSA B64.4; or (ii) an RPF backflow preventer complying with CSA B64.4.1. (f) Class 6 fire protection systems shall be protected by (i) a DCVA backflow preventer complying with CSA B64.5; (ii) a DCVAF backflow preventer complying with CSA B64.5.1; (iii) an RP backflow preventer complying with CSA B64.4; or (iv) an RPF backflow preventer complying with CSA B64.4.1. The type of protection shall be determined by a survey of the premises and an assessment of the hazard. (g) Where premises isolation backflow protection with an RP backflow preventer is required on the water service pipe at an industrial, commercial, or domestic service connection that is located on the same premises as the fire service pipe in Class 3, Class 4, Class 5, and Class 6 fire protection systems, backflow protection with an RP backflow preventer complying with CSA B64.4 or an RPF backflow preventer complying with CSA B64.4.1 shall also be provided on the fire service connection.

Table 3 Selection guide for backflow preventers for fire protection systems
(See Clauses 5.4.1 and 5.5.2.)
Pipe and fittings made of materials acceptable for potable water systems Residential “partial flow through” system ✓ ✓ ✓ ✓ ✓ ✓ ✓

Pipe and fittings made of materials not acceptable for potable water systems With antifreeze Class 1, Class 2, or other additives; or Class 3 system any class system ✓ ✓ — — ✓ ✓ — — — — — ✓ ✓ —

Type of device* DCVA DCVAF DuC DuCF RP RPF SCVAF

CSA Standard designation B64.5 B64.5.1 B64.6 B64.6.1 B64.4 B64.4.1 B64.9

Class 1 system ✓ ✓ — — ✓ ✓ ✓

*The “F” at the end of the acronym indicates that the backflow preventer is only for use on fire protection systems.

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5.5.3
Backflow preventers specified in Clause 5.5.2 shall be installed upstream of the fire department pumper connection.

5.6 Backflow from water fill stations 5.6.1
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Any outlet used on a temporary or permanent basis to dispense potable water from the water distribution system to water-hauling equipment shall be protected against backflow caused by back siphonage or back pressure with an RP backflow preventer.

5.6.2
The water fill station piping shall be installed to enable the water downstream of the final control valve to automatically drain to atmosphere when the connection to the water-hauling equipment is disconnected, at the end of each fill cycle.
Note: See Annex C for additional information on water-hauling equipment.

5.7 Backflow from temporary water services
Any outlet used to dispense potable water from the water distribution system to supply a temporary water service for construction or other purposes shall be protected against backflow caused by back siphonage or back pressure with (a) an RP backflow preventer, where there is no final connection to a plumbing system; (b) a DCVA backflow preventer, where the temporary service is connected to a plumbing system that would be regarded as a low or moderate hazard; or (c) an RP backflow preventer, where the temporary service is connected to a plumbing system that would be regarded as a high or severe hazard.

5.8 Backflow from irrigation systems 5.8.1 Above-ground irrigation systems
Any outlet used to dispense potable water from the water distribution system to supply a non-chemical-injected, above-ground irrigation system shall be protected against backflow caused by back siphonage with one of the following: (a) an HCVB device located at the hose bibb and installed downstream of the irrigation system shut-off, solenoid, or other control valves; (b) an AVB device installed downstream of the irrigation system shut-off, solenoid, or other control valves, provided that (i) the irrigation system is not in continuous use for more than 12 h at any one period of time; and (ii) the distance to the critical level of the AVB device is measured relative to the highest point of the irrigation system (see Clause 4.3.3.4); or (c) a device specified in Clause 5.8.2.

5.8.2 In-ground irrigation systems
Any outlet used to dispense potable water from the water distribution system to supply an in-ground irrigation system shall be protected against backflow caused by back siphonage with the following: (a) for systems without injection of chemicals: (i) a PVB device installed upstream of the irrigation system shut-off or other control valves and at least 300 mm above the highest point of the irrigation system; or (ii) a DCVA backflow preventer installed upstream of the irrigation system shut-off or other control valves; or (b) for systems with injection of chemicals, an RP backflow preventer installed upstream of the irrigation system shut-off valves.

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Selection and installation of backflow preventers

6 Installation of backflow preventers and vacuum breakers
6.1 General requirements 6.1.1 Accessibility
Backflow preventers and vacuum breakers shall be installed in readily accessible areas to facilitate inspection, field testing, and maintenance.
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Note: It is not recommended that backflow preventers or vacuum breakers be installed in confined spaces. See Clause 6.11.

6.1.2 Clearances
Except when the device is installed within an enclosure that complies with ASSE 1060, the minimum clearances specified in Table 4, or the manufacturer’s recommendations, whichever are greater, shall be used when installing backflow preventers or vacuum breakers.

Table 4 Clearances, mm
(See Clause 6.1.2.)
Minimum clearance Type of device DCVA DCVAF PVB RP RPF SCVAF SRPVB Centreline height above the floor Minimum 750 750 — 750 750 750 — Maximum* 1500 1500 1500 1500 1500 1500 1500 Between the bottom of the relief valve and the floor — — — 300 300 — — Above the device 300 300 300 300 300 300 300 In front of Behind the the device† device† 750 750 750 750 750 750 750 20 20 20 20 20 20 20

*Installations with a greater centreline height may be used if provided with a fixed platform. †To the nearest wall or obstruction. Notes: (1) An em-dash (—) indicates that there is no requirement specified in this Standard. (2) Clearances might have to be increased for backflow preventers with side-mounted test cocks or relief valves or when the sight tube method of testing is used.

6.1.3 Support and restraint
Backflow preventers and vacuum breakers shall be adequately supported and restrained to prevent lateral movement. Installation accessories, such as pipe hangers, braces, saddles, stanchions, and piers, shall be used to support backflow preventers and vacuum breakers and shall be placed in a manner that will not obstruct access to the device for testing and maintenance or interfere with the operation of the relief valve (on RP backflow preventers).

6.1.4 Bypasses
Bypasses around backflow preventers or vacuum breakers shall be prohibited, except where an equivalent backflow preventer is installed on the bypass (see Clause 6.7).

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6.1.5 Field testing at installation
The following backflow preventers and vacuum breakers shall be field tested in accordance with CSA B64.10.1 at the time of initial installation: (a) PVB devices; (b) SRPVB devices; (c) DCVA and DCVAF backflow preventers; (d) RP and RPF backflow preventers; and (e) SCVAF backflow preventers.
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6.1.6 Installation of DCAPC backflow preventers
When installing DCAPC backflow preventers the following shall apply: (a) The piping or fittings installed downstream of a DCAPC backflow preventer or attached to its atmospheric port shall not be made of copper or copper alloy. (b) The atmospheric port of a DCAPC backflow preventer shall not be directly connected to the drain. When a tube is attached to the atmospheric port to extend the vent, the tube shall have an air gap at the discharge or termination point. (c) Appropriate measures shall be taken to accommodate the flow during backflow conditions, as water or carbon dioxide will be discharged from the atmospheric port. In addition, adequate ventilation and drainage, as recommended by the manufacturer, shall be provided for the discharge from the atmospheric port.
Note: See Clause 7 of CSA B64.3.1 and the manufacturer’s installation instructions.

6.1.7 Flushing
Before a backflow preventer or vacuum breaker is installed, the pipeline shall be thoroughly flushed to remove all foreign material that could foul the operation of the device.

6.2 Sizing
To avoid excessive pressure loss, backflow preventers and vacuum breakers shall be sized according to the manufacturer’s recommendations.

6.3 Working pressures and temperatures
Working pressures and temperatures for backflow preventers and vacuum breakers shall be in accordance with the applicable product Standard of the CSA B64 Series. The manufacturer’s literature should be consulted for the actual working pressures and temperatures.

6.4 Shut-off valves and test cocks 6.4.1
Shut-off valves shall be provided as part of the following backflow preventers and vacuum breakers: (a) PVB devices; (b) SRPVB devices; (c) DCVA backflow preventers; (d) DCVAF backflow preventers; (e) RP backflow preventers; (f) RPF backflow preventers; and (g) SCVAF backflow preventers.

6.4.2
Shut-off valves shall have resilient seats providing a drip-tight shut-off.
Note: Shut-off valves intended for fire protection service should be of the indicating type.

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Selection and installation of backflow preventers

6.4.3
Test cocks shall (a) have resilient seats; (b) not be metal-to-metal; and (c) provide a drip-tight shut-off.

6.5 Strainers
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An in-line strainer shall be installed where water contains foreign material that could lodge on or erode the seating surfaces.

6.6 Location 6.6.1
Air gaps, backflow preventers, or vacuum breakers with vents to atmosphere shall not be installed in a corrosive or polluted atmosphere, because the contaminated air can enter the piping system through the air gap or open vent or cause the backflow preventer or vacuum breaker to malfunction.

6.6.2
RP backflow preventers shall not be installed in a below-grade pit or vault.

6.6.3
DCVA backflow preventers shall not be installed in a below-grade pit or vault unless the pit or vault can be maintained in a dry condition.
Note: A permanently installed sump pump may be acceptable to the regulatory authority.

6.6.4
When a DCVA backflow preventer is installed in a below-grade pit or vault, all test cocks on the device shall be plugged using a means that is watertight.

6.6.5
The location of backflow preventers and vacuum breakers shall not hinder the operation of other system safety devices.

6.6.6
PVB devices shall be installed only in areas where water discharge from the vent valve during initial pressurization will not be objectionable, or where the spillage can be safely directed to a drain to prevent property damage. This requirement shall not apply to SRPVB devices.

6.7 Parallel service
For installations where uninterrupted service is a necessity, backflow preventers or vacuum breakers of equal size shall be provided in parallel. Each device shall be in operation normally. See Clause 6.1.4.

6.8 Connections to drains 6.8.1
Relief ports shall not be directly connected to a drain. Adequate drainage, as recommended by the manufacturer, shall be provided for discharge from relief ports.

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6.8.2
A connection to the relief port of an RP backflow preventer shall be made using the manufacturer’s drain connection fitting, and the pipe from the outlet of the drain connection fitting shall (a) be at least equal in size to that of the drain connection fitting; (b) be rigid; (c) slope downward from the backflow preventer; and (d) terminate with an indirect connection (air break) above a floor drain, sump, or other safe location.
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6.9 Thermal expansion
When the installation of a backflow preventer creates a closed piping system (e.g., zone, area, or premises isolation), one of the following means shall be installed to protect against the increase of pressure due to thermal expansion: (a) a suitably sized diaphragm-type expansion tank appropriate for use within a potable water system; (b) an auxiliary thermal expansion relief (TER) valve set at a pressure of no more than 550 kPa. The TER valve shall be designed for repeated use and shall comply with the requirements of CSA B125.3; or (c) other means acceptable to the regulatory authority.

6.10 Installation orientation
Backflow preventers shall be installed in an orientation in which they have been tested and have shown compliance with the applicable Standard of the CSA B64 Series.

6.11 Enclosures and protection from freezing (see Figure 21) 6.11.1
Backflow preventers and vacuum breakers installed in areas subject to freezing shall be protected in a manner acceptable to the regulatory authority.

6.11.2
Insulation or any other protection of a backflow preventer or vacuum breaker shall not interfere with its operation, testing, or maintenance.

6.11.3
Insulation applied directly to a backflow preventer or vacuum breaker shall be removable to allow access for testing and maintenance.

6.11.4
Insulated enclosures (whether supplied with or without heat) shall comply with the requirements of ASSE 1060.

6.11.5
An enclosure complying with ASSE 1060 is an alternative to any location that would be considered a confined space.

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One-way drain (each side)

Figure 21 Typical enclosure
Optional heater location

(See Clause 6.11.)

One-way drain

Selection and installation of backflow preventers

B64.10-07

Annex A (informative) How backflow can occur
Note: This Annex is not a mandatory part of this Standard.

A.1 Back siphonage
A.1.1
For back siphonage to occur, at least four conditions must occur simultaneously: (a) pressure in the potable water system below atmospheric; (b) an open supply valve; (c) the outlet of a supply valve immersed in a fluid other than potable water; and (d) absence of protection from back siphonage (this includes the malfunctioning of an existing device or method). If any one of the four conditions described in Items (a) to (d) does not exist, the potable water system will not be contaminated.

A.1.2
The main reasons for the water pressure to fall below atmospheric are (a) a break in the water main; (b) drainage of the potable water system for repairs; or (c) an abnormally high demand on another part of the potable water system. Breaks in water mains do occur and are repaired by the municipality. It is standard practice to loop water mains so that a high demand at one point is fed from two directions, thus minimizing the pressure drop that occurs.

A.1.3
When a high demand is caused by a fire pumper truck, a negative pressure is likely to occur in the potable water system. The chance that a pressure below atmospheric will occur increases with the height of the building and the rate of water withdrawal. This situation is illustrated in Figure A.1 and explained as follows: (a) Under normal conditions, the pressure at A is always sufficient to provide the flow pressure required at outlets B to E. (b) When the fire pumper starts drawing water from the water main or the potable water supply system is drained for repairs, the pressure at A is reduced, and a corresponding pressure reduction occurs at B, C, D, and E. (c) The pressure at A can fall to a pressure less than that corresponding to a column of water the same height as E. When this occurs, a suction pressure occurs at E that is equal to the difference between A and E. (d) If the difference is greater than the height between D and E, both D and E will be subjected to the same suction pressure, as the effect of the column of air is insignificant. (e) The pipes supplying E and D are, of course, still full of water, since the valves are normally closed. If one of those valves is opened under the conditions described in Item (d), air will be drawn into the potable water system, and the surface of the water in the riser will fall to some point F corresponding to the pressure at A, expressed as an equivalent column of water. (f) If E or D is directly connected to a fluid and there is no air gap, and a backflow preventer has not been installed, the fluid will be drawn into the riser. Back siphonage is considered to have occurred and will continue to occur until the surface of the contaminating fluid falls below the outlet and air can be drawn into the potable water system.

July 2007

Selection and installation of backflow preventers

(g) When air is drawn into the potable water system, the height of fluid and water in the riser will level off at F. When the fire is over, the pressure at A will rise to normal. The water and fluid in the riser will then be forced back to where the fluid came from, as the valve is still open.

A.1.4
Another reason that the pressure in the riser (see Figure A.1) could fall below atmospheric is an accidental break in the water main, for example at A. The pressure at A will fall until it is equal to the resistance to flow from the break into the ground, and point F would probably be found at about ground level. Back siphonage could then occur as described in Clause A.1.3.

A.2 Back pressure backflow
A.2.1
When the pressure causing backflow is higher than atmospheric pressure, it is referred to as back pressure. Such back pressure is usually caused by mechanical means such as a pump or by thermal means such as a boiler. For backflow to occur, the following four conditions must exist: (a) the back pressure has risen above the supply pressure (or the supply pressure has fallen below the back pressure); (b) a supply valve is open; (c) the potable water system is connected to a device or system that contains a fluid other than potable water; and (d) no backflow preventer has been installed (or the device is not working).

A.2.2 A.2.2.1
Of the four conditions listed in Clause A.2.1, it can generally be assumed that conditions (b) and (c) exist. Unfortunately, in many industrial plants, condition (d) seems to be more common than it should be. Since the pressure on the supply side can vary, it is necessary to consider how a pressure variation can result in the development of back pressure, as explained in Clauses A.2.2.2 and A.2.2.3.

A.2.2.2
Probably the most common examples of piping systems in which pumps can cause back pressure are found in docked ships and in industrial plants where a secondary or alternative water system exists. In these cases, the municipal potable water and alternative water systems are interconnected. As long as a backflow preventer is installed and is in working order, no back pressure is exerted on the municipal potable water system, and backflow cannot occur. Generally, in industry, one system will be used as the principal supply, with the other being connected as an alternative supply in case of an emergency. When ships are in harbour they are generally connected to the public water mains for improved fire protection and refilling of their potable water storage tanks. The ships no longer have to rely on their own mechanical pumping system, which can be temporarily shut down for servicing. It is common practice to flush a ship’s fire protection systems with dockside potable water. After the flushing operation, the ship’s fire pumps are tested to ensure that they are functioning properly. These pumps may generate a pressure of 1400 kPa, which is considerably higher than that of the municipal potable water supply system. If only a shut-off valve has been installed on the municipal potable water system and no backflow preventer is provided at the connection point of the ship’s water system, sea or lake water will be forced into the municipal potable water system whenever the shut-off valve is open and the ship’s pumps are operated.

July 2007

B64.10-07

A.2.2.3
Back pressure can also be caused by thermal means when a potable water system is directly connected to a boiler and the backflow preventer is either missing or defective. In such cases the pressure in the boiler is that provided by the potable water system, regardless of whether it is a hot water boiler or a steam boiler. Back siphonage can occur in the same manner as discussed in Clause A.1, but back pressure can only be developed if the boiler controls fail and overheating occurs. The overheating can cause steam to be formed whose volume is many times that of hot water, so that the water in the boiler is forced back into the potable water system. If steam is not formed, backflow due to back pressure will be relatively small and equal to the change in volume of water corresponding to its increase in temperature.

D F

To fire department pumper suction connection

Drain valve A

Public water supply

Figure A.1 Example of potential back siphonage hazard
(See Clauses A.1.3 and A.1.4.)

July 2007

Selection and installation of backflow preventers

Annex B (informative) Guide to the assessment of hazards
Note: This Annex is not a mandatory part of this Standard.

B.1
To protect the municipal and private potable water supply systems from contamination, the authority administering the local cross-connection control program has several options available when determining the location of backflow preventers within industrial, commercial, and residential premises: (a) The first option is based on a containment theory according to which backflow protection is installed on the incoming service, providing premises isolation that utilizes a minimum number of backflow preventers to isolate the municipal potable water system from the private system, but that does not protect the consumer from the source of contamination via internal cross-connections. (b) The second option is based on internal protection: backflow preventers are either installed on individual water usages or zones of usage. This approach protects the private potable water system from internal contamination, but does not adequately protect the municipal potable water system, because of the complexity of the plumbing system (e.g., plumbing modifications and occupancy changes), that are inherent in industrial, commercial, or residential developments. (c) The third option is based on combining premises, zone, and individual protection to ensure that both the public and private potable water supply systems are protected from contamination.

B.2
Tables B.1 and B.2 are a guide to the degree of hazard, but do not provide a complete list of potential hazards.

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B64.10-07

Table B.1 Guide to degree of hazard — Point of use cross-connections
(See Clauses 5.4.1 and B.2.)
Source of pollution or contamination Agricultural chemical (sprayer)
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Degree of hazard Severe Moderate Moderate Moderate Severe Severe Severe Severe Moderate Moderate Moderate Severe Minor Moderate Moderate to severe Moderate to severe Minor to moderate Severe Severe Severe Moderate to severe Severe Severe Moderate Severe Moderate Minor Severe Minor (Continued)

Air compressor oil cooler Animal watering Aspirator (non-toxic) Aspirator (toxic) Autoclave Autopsy and mortuary equipment Auxiliary water supply Baptistery Basin Bathtub (all) Bedpan washer Beverage dispensing equipment (no carbonator) Beverage dispensing equipment (with carbonator) Bidet Bottle washer Bread making equipment Canopy washers Carwash Chemical feed tank Chiller tank (closed, no chemicals) Chiller tank (open or with chemicals) Chlorinator Clothes washer (residential) Condensate tank Condensate tank (top feed) Cooking kettle (for food only) Cooling condenser, AC unit (solenoid downstream) Cooling condenser, AC unit (solenoid upstream)

July 2007

Selection and installation of backflow preventers

Table B.1 (Continued)
Source of pollution or contamination Cooling tower Cuspidor De-aerator (bottom feed)
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Degree of hazard Severe Severe Severe Moderate Severe Minor Severe Severe Moderate Moderate Moderate Moderate Minor Severe Eyewash/shower to be installed upstream of the zone isolation Minor to severe Severe Moderate Severe Severe Moderate to severe Severe Severe Severe Severe Moderate to severe Severe Moderate Minor to moderate Moderate to severe (Continued)

De-aerator (top feed) Degreasing equipment Dental delivery system (water supply) Dental vacuum pump Detergent dispenser Dipper well in ice cream parlour or restaurant Dish rinse unit with flex hose Dishwasher (commercial) Dishwasher (residential) Distiller Dockside marine facility Emergency eyewash/shower Flexible shower head with hose Floor drain with flushing rim Flush tank Flushing equipment device Flushometer Fountain, ornamental Fountain, ornamental (chemicals added) Fume hood Garbage can washer Garbage disposal unit Heat exchanger Heating system (chemicals added) Heating system (no chemicals added) Heating system (residential; boiler with copper or plastic piping; no chemicals added) Hose connection (other than residential)

July 2007

B64.10-07

Table B.1 (Continued)
Source of pollution or contamination Hose connection (residential) Hospital (active treatment area) Hospital (non-treatment area)
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Degree of hazard Minor to moderate Severe Moderate Moderate Moderate Severe Moderate Moderate to severe Severe Severe Severe Moderate Minor Severe Moderate to severe Severe Moderate Moderate Severe Severe Moderate Severe Severe Minor to moderate Severe Severe Minor to severe Severe Moderate Severe Minor (Continued)

Hot tub or spa Humidifier Humidifier with sump (chemicals added) Hydrotherapy bath Ice machine for commercial restaurant Ice making equipment for sports arena Industrial fluid system Irrigation system (chemicals injected) Irrigation system (no chemicals injected) Lab bench equipment (non-toxic) Lab bench equipment (toxic) Lab faucet Laboratory Laundry machine Lavatory Lethal substance Livestock equipment Mixing tee with steam and water Mortuary or morgue Non-potable water Optician or ophthalmology equipment Photo lab sink Pipette washer Piping to chemical dispensers Plating tank Potato peeler Poultry barn Pressure washer (no aspirator)

July 2007

Selection and installation of backflow preventers

Table B.1 (Continued)
Source of pollution or contamination Pressure washer (with aspirator) Private fire hydrants Private water source
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Degree of hazard Severe Moderate Severe Moderate Severe Severe Severe Minor Moderate Severe Severe Severe Severe Moderate Severe Severe Severe Moderate Severe Severe Moderate Moderate Minor to moderate Moderate Severe Minor Moderate Moderate Minor Moderate Moderate (Continued)

Pump primer line (non-toxic) Pump primer line (toxic) Radiator flushing equipment Restricted area Reverse osmosis equipment Reverse osmosis equipment with backwashing Reverse osmosis equipment with chemical cleaning Serrated faucets Sewage ejectors Sewage pump Shampoo sinks Sizing vats Solar energy units Solution tanks Spa or hot tub Specimen tank Steam boiler Steam cleaner Steam generator Steam table Sterilizer (condensate cooling only) Sterilizer (connection into chamber) Still Swimming pool (direct connection) Swimming pool (other than residential) Swimming pool (residential) Swimming pool makeup tank Teeth cleaning equipment (veterinary type)

July 2007

B64.10-07

Table B.1 (Concluded)
Source of pollution or contamination Trap primer Vending machine with no carbonators Wash rack
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Degree of hazard Severe Minor Severe Moderate Severe Moderate Moderate Severe Minor Severe Moderate Severe

Wash tank Wash tanks (toxic) Water closet (flushometer type) Water closet (tank type) Water hauling equipment (see Annex C) Water softener Water softener drain Wok table (for Oriental cooking) with submerged inlet X-ray equipment

July 2007

Selection and installation of backflow preventers

Table B.2 Guide to degree of hazard — Premises
(See Clauses 5.3.1.2, 5.3.4, and B.2.)
Type of building or facility Airport
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Degree of hazard Moderate Moderate to severe Moderate to severe Moderate Severe Severe Moderate Severe Severe Moderate Severe Severe Severe Severe Moderate Severe Severe Severe Minor to moderate Moderate to severe Severe Moderate Severe Severe Severe Minor Severe Severe Moderate to severe (Continued)

Animal feed lot Animal stock yard Apartment building Aquaculture farm Aquarium (public) Arena Asphalt plant Auto body shop Auto dealership Automotive repair Automotive repair shop Beverage processing plant (includes distillery and brewery) Blood clinic Campsite Campsite with RV hook-ups or dump-stations Carwash Chemical plant Church Commercial premises Concrete plant Dental office Dental surgery facility Dock and marine facility Dry cleaning plant Duplex housing with shared service Dye plant Exhibition ground Farm

July 2007

B64.10-07

Table B.2 (Continued)
Type of building or facility Film processing facility Fire station Fish farms or hatchery
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Degree of hazard Severe Moderate to severe Severe Severe Moderate Moderate to severe Severe Moderate to severe Moderate Moderate Severe Moderate Moderate to severe Moderate Severe Severe Moderate Moderate Moderate to severe Severe Moderate Severe Severe Severe Moderate Severe Moderate Severe Moderate Severe Severe (Continued)

Food processing plant Fuel dispensing facility Funeral home Garbage transfer facility Golf course Grocer Hair salon Hospital Hotel Industrial and institutional premises Kennel Laboratory Laundry (commercial) Laundry (commercial, coin-operated) Manufacturing plant (not specified) Marina (pleasure-boat) Meat packing plant Medical clinic (non surgical) Medical clinic (surgical) Milk processing plant Mining facility Mobile home park Mortuary or morgue Motel Motorcycle repair facility Nursing home Oil refinery Paint manufacturing plant

July 2007

Selection and installation of backflow preventers

Table B.2 (Continued)
Type of building or facility Penitentiary Petroleum processing or storage facility Pharmaceutical manufacturing facility
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Degree of hazard Moderate Severe Severe Severe Severe Severe Severe Severe Severe Severe Severe Severe Severe Severe Severe Severe Severe Minor Moderate Moderate Severe Severe Severe Moderate Minor Moderate to severe Moderate to severe Moderate to severe Severe Severe Severe (Continued)

Photo processing facility Plants using radioactive material Plastic manufacturing plant Plating shop Poultry farm Power generating facility Premises where access is prohibited Printing plant Pulp and/or paper plant Radiator shop Recycling facility Refinery, petroleum processing Rendering facility Research building Residential premises Restaurant School (elementary, junior high, and senior high) Sewage dump station Sewage treatment plant Steel manufacturing plant Swimming pool facility Townhouse (shared services) University Veterinary clinic Waste disposal plant Wastewater facility Wastewater pump station Wastewater treatment plant

July 2007

54
Zoo Severe Severe Severe Moderate Water park Water filling station Water treatment plant Type of building or facility Water treatment pump station

B64.10-07

Table B.2 (Concluded)
Severe Degree of hazard

July 2007

Selection and installation of backflow preventers

Annex C (informative) Water-hauling equipment and backflow devices
Note: This informative (non-mandatory) Annex has been written in normative (mandatory) language to facilitate adoption where users of the Standard or regulatory authorities wish to adopt it formally as additional to requirements to this Standard.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

C.1
An RP backflow preventer or an air gap shall be installed on all water-hauling equipment. See Figures C.1 and C.2.
Note: For air gaps, see Clauses 3.1 and 4.1.

Air gap Permanently attached pipe Hose connection

Figure C.1
(See Clause C.1.)

RP backflow preventer

Figure C.2
(See Clause C.1.)

July 2007

B64.10-07

Annex D (informative) Conversion tables
Note: This Annex is not a mandatory part of this Standard.

Table D.1 Conversion factors
To convert °C kPa kPa L L/s L L/s m m2 mm N N•m To °F lbf/in2 (psi) lbf/ft2 imperial gallon imperial gal/min (imperial gpm) US gallon US gal/min (US gpm) ft ft2 in lbf lbf•in Multiply by 1.8 and add 32 0.145 20.885 0.220 13.198 0.264 15.850 3.281 10.764 0.0394 0.225 8.851

Table D.2 Flow rate equivalencies
L/s 0.19 0.32 0.63 1.00 1.26 1.89 2.52 3.78 4.73 5.67 6.30 US gpm 3.0 5.0 10.0 15.9 20.0 30.0 40.0 60.0 75.0 90.0 100.0

July 2007

Selection and installation of backflow preventers

Annex E (informative) Model backflow prevention bylaw
Notes: (1) This informative (non-mandatory) Annex has been written in normative (mandatory) language to facilitate adoption where users of the Standard or regulatory authorities wish to adopt it formally as additional to the requirements in this Standard. (2) If a regulatory authority adopts this bylaw, consideration should be given to exceptions or changes that may be required due to local or provincial regulations.

E.1
Figure E.1 comprises a model bylaw for enforcement of a cross-connection control program (CCCP) by the regulatory authority.

Backflow Prevention Bylaw 1 Definitions
For the purposes of this Bylaw, the following definitions shall apply: Authorized functions list — the list of functions and the persons authorized to carry out such functions, as outlined in Table 1. Backflow — the reversal of the normal direction of the flow of water. Backflow preventer — a device that prevents backflow. Building — refer to the definition of “building” in [insert reference to provincial building code here]. Cross-connection — any actual or potential connection between a potable water system and any source of pollution or contamination.
Note: Bypass arrangements, jumper connections, removable sections, swivel or changeover devices, or any other temporary or permanent connecting arrangements through which backflow can occur are considered cross-connections.

Owner — any person, firm, or corporation having control over property to which this Bylaw applies. Potable water — water safe for human consumption. Premises isolation — isolation of the water located within a building or structure from the municipal water supply. Regulatory authority (municipality) — the Corporation of [insert name of city, town, or regulatory authority here], including its employees, servants, and agents.

Figure E.1 Model backflow prevention bylaw
(Continued)

July 2007

B64.10-07

2 Contamination and backflow prevention
No person shall connect, cause to be connected, or allow to remain connected to the plumbing system or water distribution system any piping, fixture, fitting, container, or appliance that, under any circumstances, might allow any untreated water, waste water, pollutant, or any other liquid, chemical, or substance to enter the plumbing system or potable water distribution system.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

3 Inspection for cross-connections — Access
3.1
The regulatory authority shall be allowed access, with reasonable notice, to any premises connected to the water distribution system for the purpose of performing inspections to locate possible cross-connections. The regulatory authority may request a routine cross-connection inspection of the premises (at the owner’s expense), to be performed by an approved company or person as described in the Authorized Functions List (Table 1).

3.2
The regulatory authority shall be allowed access, with reasonable notice, to any premises connected to the water distribution system for the purpose of performing inspections to verify compliance with Section 8.

3.3
Where the access requirements of Sections 3.1 and 3.2 are not fulfilled, a written notice may be issued by the regulatory authority outlining a revised deadline for access to the premises in question. If access is not provided by this deadline, the regulatory authority may, at its discretion, shut off the supply of water to the premises until the access is provided.

3.4
If a condition is found to violate Section 2, the regulatory authority may immediately carry out an inspection and may issue any notice required to obtain compliance with Section 2.

4 Notices and orders to correct cross-connections
If the person(s) to whom the regulatory authority has issued notice fails to comply with that notice, the regulatory authority may (a) give further notice to the person(s) to correct the fault (at his or her expense) within a specified time period; if the notice is not complied with, the regulatory authority may then shut off the water service; (b) issue an order, citing unsafe conditions, in accordance with [insert reference to provincial building code here] to correct the condition that could be hazardous to the health or safety of persons in the normal use of the building, persons outside the building, or persons whose access to the building has not been reasonably prevented; and (c) without notice to the consumer, shut off the water service where the commissioner of works has determined, in his or her sole discretion, that an immediate threat of contamination to the water system exists that can endanger public health or safety.

Figure E.1 (Continued)
(Continued)

July 2007

Selection and installation of backflow preventers

5 Premises isolation
5.1
Where, in the opinion of the regulatory authority, a risk of possible contamination of the potable water distribution system exists, the owner, on notice from the regulatory authority, shall install premises isolation in addition to any other backflow protection devices on the premises.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

5.2
Premises isolation shall be installed (a) in buildings of high or severe hazard in accordance with the premises isolation requirements outlined in [insert reference to provincial building code here]; or (b) as required by the regulatory authority.

6 Required surveys
6.1
A cross-connection survey of the plumbing system of all existing industrial, commercial, institutional, and multi-residential buildings and structures, except buildings of residential occupancies within the scope of [insert reference to provincial building code here], shall be completed (at the owner’s expense) by the approved personnel specified in the Authorized Functions List (Table 1).

6.2
The cross-connection survey shall be completed along with a report and sent to the regulatory authority within 30 days of the date of the request by the municipality. The cross-connection survey report shall include existing backflow preventers and cross-connections, corrective measures, recommendations, and a schedule of work to be completed.

6.3
A cross-connection survey shall be completed every 5 years from the date of the first requested survey or as required by the regulatory authority.

7 Selection and installation of backflow preventers
The selection and installation of backflow preventers shall be in accordance with [insert reference to provincial building code here].

8 Maintenance and field-testing of backflow preventers
8.1
Where required by [insert reference to provincial building code here] and CSA B64.10.1, all backflow preventers shall be inspected and tested (at the owner’s expense) to demonstrate that the devices are in proper working condition.

Figure E.1 (Continued)
(Continued)

July 2007

B64.10-07

8.2
When the results of the test in Section 8.1 demonstrate that a backflow preventer is not in proper working condition, the owner shall make all necessary repairs or replace the device within 5 days.

8.3
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

If the owner does not make the appropriate repairs or replace the defective device within 5 days, the regulatory authority may issue a notice (see Section 3.4) or may shut off the water service(s).

8.4
If the owner fails to have a backflow preventer tested, the regulatory authority may notify the owner that the backflow preventer must be tested within a specified time.

8.5
If the owner fails to have a backflow preventer tested within the specified time of the notice described in Section 8.4, the regulatory authority may shut off the water service(s) until the backflow preventer has been tested and approved as required by Section 8.1.

8.6
Failure to comply with Sections 8.1 to 8.5 can result in penalties as described in Section 4.

9 Removal of backflow preventers
No person shall remove a backflow preventer or any part thereof after it has been installed, and no owner of a building or structure in which a backflow preventer is installed shall cause or permit the removal of such a device, unless the purpose of such removal is to (a) facilitate the repair of the device, with the device replaced immediately after the repair is carried out; (b) replace the device with another device that meets or exceeds the provisions of this Bylaw; or (c) remove a device when the fixture or equipment has been taken out of service and removed.

10 Backflow test equipment maintenance
Where required by [insert reference to provincial building code here] and CSA B64.10.1, all equipment used to test backflow preventers shall be verified or calibrated for accuracy.

11 Authorized functions
Only those persons listed in the Authorized Functions List (see Table 1) shall carry out the corresponding functions set out in such list.

Figure E.1 (Continued)
(Continued)

July 2007

July 2007 Item 1 2 Authorized function Carry out crossconnection survey Install, relocate, or replace backflow preventer Repair backflow preventer Test backflow preventer Complete Items 1, 2, 3, and 4 in relation to fire protection systems Complete Items 3 and 4 in relation to lawn sprinkler systems Professional engineer with tester’s licence ✓ — ✓ — 3 4 5 ✓ ✓ ✓ ✓ ✓ ✓ 6 ✓ ✓

Table 1 Authorized functions list
Municipality of _________________ Bylaw number __________________
Certified engineering technologist with tester’s licence* Licensed master plumber with contractor’s and tester’s licence ✓ ✓ Journeyman plumber with tester’s licence† ✓ ✓ Apprentice plumber with tester’s licence‡ — ✓ Fire system sprinkler fitter with a tester’s licence — — Lawn irrigation system installer with tester’s licence — —

✓ ✓ ✓

— — ✓

— ✓ — Selection and installation of backflow preventers

✓

—

Figure E.1 (Concluded)

CSA Standard

B64.10.1-07 Maintenance and field testing of backflow preventers

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Maintenance and field testing of backflow preventers

B64.10.1-07 Maintenance and field testing of backflow preventers
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

1 Scope
1.1
This Standard specifies requirements for the maintenance and field testing of backflow preventers.

1.2
This Standard does not specify requirements for the selection and installation of backflow preventers. Such requirements are specified in CSA B64.10.

1.3
In CSA Standards, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; “should” is used to express a recommendation or that which is advised but not required; “may” is used to express an option or that which is permissible within the limits of the standard; and “can” is used to express possibility or capability. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.

1.4
This Standard is written in SI (metric) units. For conversion tables, see Annex D of CSA B64.10. Vacuum is expressed in pressure below ambient.

2 Reference publications
This publications referenced in this Standard are listed in Clause 2 of CSA B64.10.

3 Definitions, abbreviations, and symbols
The definitions, abbreviations, and symbols given in Clause 3 of CSA B64.10 apply in this Standard.

July 2007

B64.10.1-07

4 Devices to be field tested, frequency, and reporting
4.1 Devices to be field tested 4.1.1
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

To ensure that continuing backflow protection is available, the following backflow preventers shall be checked and field tested in accordance with Clauses 4.2 and 4.3 by a backflow preventer tester (see Clause 5.2.1): (a) DCVA and DCVAF backflow preventers; (b) RP and RPF backflow preventers; (c) PVB and SRPVB devices; and (d) SCVAF backflow preventers.

4.1.2
Air gaps on severe hazard applications shall be inspected in accordance with Clause 4.2. Other backflow preventers shall be visually checked periodically.

4.2 Frequency of field testing
The backflow preventers specified in Clause 4.1 shall be field tested in accordance with the applicable requirements specified for each device in Clauses 8.1, 8.2, and 8.3 at the following times: (a) upon installation; (b) when cleaned, repaired, or overhauled; (c) when relocated; (d) annually; and (e) as required by the regulatory authority.
Note: Recommended field testing procedures are provided in Annex A.

4.3 Reporting 4.3.1
Test results shall be reported on the form appropriate for the type of backflow preventer and procedure. Sample reporting forms are shown in Figures 1(a), 1(b), and 1(c).

4.3.2
Fire departments and fire alarm companies shall be notified when a fire protection service is to be shut down for field testing.

July 2007

Maintenance and field testing of backflow preventers

Testing and inspection report
Double check valve backflow preventer and pressure vacuum breaker
Location address Owner of device
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

DCVA, PVB
Mailing address

Occupant

Owner contact Owner address Name of certified tester Business name Make of test kit Model number Tester certification number Business address Serial number

Telephone Postal code Telephone Postal code Calibration due date

Double check valve backflow preventer/Pressure vacuum breaker
Type of device DCVA Make of device PVB Model number Serial number Size

Location of device in building Type of test Initial Annual Date of test YY MM DD Line pressure at time of test kPa psi

Double check valve backflow preventer Check valve 1 Check valve 2

Pressure vacuum breaker
Test results Passed Failed kPa psi Air inlet valve Failed to open Opened at kPa psi Check valve Leaked Closed tight Pressure drop across check valve Test results Passed Failed kPa psi

Test

With flow Leaked Closed tight Pressure drop across check valve

Against flow Leaked Closed tight kPa psi

With flow Leaked Closed tight

Against flow Leaked Closed tight

Pressure drop across check valve

If the device fails the test for any reason, complete this section and note repair below
Reason for failure (if apparent)

Double check valve backflow preventer Check valve 1 Check valve 2
35 Cleaned Replaced 36 37 38 39 40 41 42 43 Disc Spring Guide Pin Retainer Hinged Pin Seat Diaphragm Other, describe above YY Against flow Leaked Closed tight kPa psi MM DD With flow Leaked Closed tight Pressure drop across check Against flow Leaked Closed tight Re-test results Passed Failed kPa psi 45 46 47 48 49 50 51 52 44 Cleaned Replaced Disc Spring Guide Pin Retainer Hinged Pin Seat Diaphragm Other, describe above 54 55 56 57 58 59 60 61 53 Cleaned

Pressure vacuum breaker
Replaced Vent Disc Vent Spring Poppet Retainer Spring Disc Guide Other, describe above

Repairs Re-test

Date of re-test With flow Leaked Closed tight

Air inlet valve Failed to open Opened at kPa psi

Check valve Leaked Closed tight Pressure drop across check

Pressure drop across check Remarks

Re-test results Passed Failed kPa psi

I certify that I have tested the above device in accordance with the City of Signature registered tester YY

Bylaw MM DD
Distribution White – Cross-connection control officer – Occupant or owner Canary – Certified tester

For office use only

Pink

Figure 1(a) Sample testing and inspection report for DCVA backflow preventers and PVB devices
(See Clause 4.3.1.)

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Testing and inspection report
Reduced pressure principle backflow preventer
Location address Owner of device
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Mailing address

Occupant

Owner contact Owner address Name of certified tester Business name Make of test kit Model number Tester certification number Business address Serial number

Telephone Postal code Telephone Postal code Calibration due date

Reduced pressure principle backflow preventer
Make of device Location of device in building Type of test Initial Annual Date of test YY MM DD Shut-off valve no. 2 Leaked Closed tight Line pressure at time of test kPa psi Model number Serial number Size

Differential pressure relief valve

Check valve 1
Leaked Closed tight Pressure differential across first check valve (no flow) kPa psi

Check valve 2
Leaked Closed tight Pressure differential across second check valve (no flow) kPa psi Test results Passed Failed

Test

Failed to open Opened at

kPa

psi

If the device fails the test for any reason, complete this section and note repair below
Reason for failure (if apparent)

Differential pressure relief valve

Check valve 1
13 Cleaned Replaced Disc Spring Guide Pin retainer Hinged pin Seat Leaked Closed tight Pressure differential across first check valve (no flow) kPa psi 22 20 21 Diaphragm Other (describe above) 23 24 25 26 27 28

Check valve 2
Cleaned Replaced 29 Disc 30 Spring Guide Pin retainer Hinged pin Seat Leaked Closed tight Pressure differential across second check valve (no flow) kPa psi 31 Diaphragm 32 Other (describe above) 33 34

Shut-off valve 2
Cleaned Replaced Disc Seat Other (describe above)

Repairs

1 2 3 4 5 6 7

Cleaned Replaced Disc upper Disc lower Spring Diaphragm lg. Upper Lower

8 9 10 11 12

Diaphragm small Upper Spacer Seat Other (describe above)

14 15 16 17 18 19

Re-test

Failed to open Opened at Date of re-test

kPa YY MM

psi DD

Re-test results Passed Failed

Remarks

I certify that I have tested the above device in accordance with the City of

Bylaw

Signature registered tester

Distribution White – Cross-connection control officer – Occupant or owner Canary – Certified tester

For office use only

Pink

Figure 1(b) Sample testing and inspection report for RP backflow preventers
(See Clause 4.3.1.)

July 2007

Maintenance and field testing of backflow preventers

Testing and inspection report
Reduced pressure principle backflow preventer, double check valve backflow preventer, pressure vacuum breaker, and spill-resistant pressure vacuum breaker
Location address Owner Type of device RP DCVA
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

RP, DCVA, PVB, SRPVB
Mailing address

Occupant Address of owner Make of device PVB SRPVB Model number Serial number

Party contacted Postal code Size

Telephone number

– –
Install date
YY

– –
MM DD

Telephone number

Location of device (i.e., building, room number) Tester’s certification number Location address Type of test (please check one) Initial Annual Replacement Tester’s equipment number Name of certified tester

Installed on what system Business name Telephone number

–
Postal code

–

Line pressure at time of test

kPa psi

Pressure differential across first check valve (no flow) Minus the opening point of relief valve kPa psi = Buffer

kPa psi kPa psi
Test results

Test

Test date
YY MM DD

Reduced pressure principle backflow preventer Double check valve backflow preventer Check valve 2 Check valve 1 Shut-off valve 2 With flow Against flow With flow Against flow Leaked Leaked Leaked Leaked Leaked Closed tight Closed tight Closed tight Closed tight Closed tight

Differential pressure relief valve

Pressure vacuum breaker or spill-resistant pressure vacuum breaker Air inlet valve Failed to open Opened at Check valve Leaked Closed tight

Failed to open Opened at

kPa psi

Passed Failed

If the device fails the initial test for any reason, complete this section and note repair below
1 2 3 4 5 6 7 8 9

Repairs

Cleaned Replaced Disc Spring Guide Pin retainer Hinge pin Seat Diaphragm Other (describe)

20 21 22 23

Cleaned Replaced Disc Seat Other (describe)

30 31 32 33 34 35 36 37 38

Cleaned Replaced Disc Spring Guide Pin retainer Hinge pin Seat Diaphragm Other (describe)

50 51 52 53 54 55 56 57 58 59 60 61

Re-test

Pressure differential across First check valve (no flow) re-test
Leaked Closed tight Leaked Closed tight

kPa psi
Leaked Closed tight

Cleaned Replaced Disc, upper Disc, lower Spring Diaphragm, large Upper Lower Diaphragm, small Upper Lower Spacer, lower Other (describe)
Failed to open Opened at kPa psi

70 71 72 73 74 75 76 77 78

Cleaned Replaced Vent disc Vent spring Poppet Retainer Spring Disc Guide Other (describe)

Results

Re-test date
YY

Leaked Leaked MM DD Closed tight Closed tight Remarks – reason for failure (if apparent)

Failed to open kPa Opened at psi

Leaked Closed tight

Re-test results Passed Failed

I certify that I have tested the above device in accordance with the City of Bylaw For office use only Distribution: White – Cross-connection control officer

Signature of certified tester

Date
YY

Canary – Certified tester

Pink – Occupant or owner

Figure 1(c) Sample testing and inspection report for RP and DCVA backflow preventers and PVB and SRPVB devices
(See Clause 4.3.1.)

5 School accreditation and tester certification and licensing
5.1 School accreditation
A school or college conducting certification or re-certification courses shall be accredited by an organization or association. The accrediting organization or association shall have minimum requirements established for the following: (a) instructor and backflow prevention device tester qualifications; (b) instructor and backflow prevention device tester re-certification qualifications; (c) course content and duration for device tester qualifications; (d) course content and duration for device tester re-certification courses; (e) examinations and minimum passing criteria for Items (c) and (d);

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(f) laboratory facilities; (g) issuance of certificates for certified or re-certified testers; and (h) current liability insurance coverage (with an expiry date no less than 6 months after the date of application for licensing or registration).

5.2 Tester certification and re-certification
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

5.2.1
To be recognized as such, a backflow prevention device tester shall have completed and passed a cross-connection control course in backflow preventer testing at an accredited school or college and shall have a certificate issued by an accrediting organization.

5.2.2
To maintain active status, the tester shall provide proof to the appropriate authority that he or she complies with the active status requirements of the accrediting organization.
Note: The appropriate authority may be the regulator or its designated representative.

5.2.3
If a tester does not maintain active status, or every 5 years, the tester shall attend and pass a re-certification course before his or her licence is accepted.

5.2.4
If a tester repeatedly submits test reports that are unacceptable because (a) information that is required to be submitted by Clause 8.1, 8.2, or 8.3 is missing or falsified on the report form; or (b) a device is reported as “passed” when the data obtained in the test indicate that the device has failed, the tester shall be required to attend and pass a re-certification course at an accredited school or college before submitting any further test reports.

5.2.5
To be re-certified, a backflow prevention device tester shall complete and pass a backflow prevention device tester re-certification course at an accredited school or college.

5.3 Tester licensing and registration
When applying to the regulatory authority for licensing or registration as a backflow prevention device tester, the individual shall have the following qualifications: (a) a certificate from an accredited organization or association as a backflow prevention device tester that has been issued, or renewed through completion of a re-certification course, within the 5 years before the date of application; (b) a current calibration certificate for test equipment (dated within the 12 months before the date of application for licensing or registration); (c) another trade or professional qualification (e.g., plumbing certificate, sprinkler fitter certificate, etc.); and (d) current liability insurance coverage (with an expiry date no less than 6 months after the date of application for licensing or registration).
Note: The regulatory authority administering the cross-connection control program should license or register backflow prevention device testers who have the above-noted qualifications.

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Maintenance and field testing of backflow preventers

6 Maintenance
6.1 General 6.1.1
If a backflow preventer has to be removed from a water line and the line is used as the electrical ground, a jumper wire shall be installed.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

6.1.2
When entering a confined space, entry procedures established by the regulatory authority shall be followed.

6.1.3
Backflow preventers designed for in-line servicing and repair shall not be replaced with a spool or pipe and shall not be reassembled while awaiting delivery of replacement parts if any parts have been removed.
Note: To eliminate the necessity of removal for servicing, many backflow preventers are designed for in-line repairs. Once a backflow preventer has been removed, no protection is provided. A false sense of protection can be given when a backflow preventer appears to be still operational.

6.1.4
Valve springs on large backflow preventers shall be removed with caution. The manufacturer’s instructions shall be consulted.

6.1.5
After repairs are completed, entrapped air shall be bled off.

6.2 RP backflow preventers 6.2.1
On RP backflow preventers, parts in the upstream check valve need not be interchangeable with the parts in the downstream check valve.

6.2.2
If an RP backflow preventer is continuously leaking from the relief port, the upstream check valve, the downstream check valve, or the relief valve has failed. The check valves shall be cleaned and the valve seats checked for damage.

6.2.3
If the downstream shut-off valve of an RP backflow preventer is closed and water begins to be discharged from the relief port, the upstream check valve shall be checked for possible leakage.

6.3 DCAPC backflow preventers 6.3.1
If the atmospheric port of a DCAPC backflow preventer discharges, the device shall be disassembled, thoroughly inspected, cleaned, and reassembled with new parts as necessary, following the manufacturer’s instructions.

6.3.2
DCAPC backflow preventers shall be checked for water and carbon dioxide (CO2) leaks before they are returned to service.

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7 Test gauges and kits
7.1 Accuracy
The accuracy of test equipment used by backflow prevention device testers shall be monitored by the regulatory authority or its designated agent.

7.2 Verification and calibration
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Mechanical test kits shall be verified or calibrated for accuracy at least annually or as required by the regulatory authority. Compliance with this requirement shall be a condition for the issuing or reissuing of a tester’s licence or registration. All verification or calibration equipment shall be traceable to a national standard.

7.3 Units
Test equipment calibrated in yard/pound units equivalent to the SI (metric) units specified in this Standard shall be acceptable.

8 Field test requirements and pass/fail criteria
Note: Recommended field test procedures are provided in Annex A.

8.1 PVB devices 8.1.1 General
To be recorded as “passed”, a PVB device shall comply with the requirements of Clauses 8.1.2, 8.1.3, and 8.1.4. If “failed” is recorded in one or more of these tests, the PVB device shall be recorded as “failed”. The test results shall be recorded as specified in Clause 4.3.1 (see Table 1).

8.1.2 Air inlet valve 8.1.2.1 Requirements
The air inlet valve shall begin to open when the internal pressure in the PVB device is at least 6.9 kPa higher than atmospheric pressure and shall be fully open when the water drains from the PVB device.

8.1.2.2 Pass/fail criteria
If the air inlet valve begins to open when the internal pressure in the PVB device is at least 6.9 kPa higher than atmospheric pressure and is fully open when the water drains from the PVB device, the test shall be recorded as “opened/passed”. If one or both requirements are not met, the test shall be recorded as “failed to open/failed”.

8.1.3 Check valve 8.1.3.1 Requirements
The check valve shall close tight for a minimum period of 2 min or until the gauge reading stabilizes, in the direction of flow, when the inlet pressure is at least 6.9 kPa higher than the outlet pressure.

8.1.3.2 Pass/fail criteria
If the check valve closes tight for a minimum period of 2 min or until the gauge reading stabilizes, in the direction of flow, when the inlet pressure is at least 6.9 kPa higher than the outlet pressure, the test shall be recorded as “closed tight/passed”. If the check valve does not close tight for a minimum period of 2 min or until the gauge reading stabilizes, the test shall be recorded as “leaked/failed”.

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Maintenance and field testing of backflow preventers

8.1.4 Static line pressure 8.1.4.1 Requirements
The static inlet line pressure shall be measured at the time of the test and recorded on the test report form.

8.1.4.2 Pass/fail criteria
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

If the static inlet line pressure at the time of testing is (a) recorded on the test report form, the test shall be recorded as “passed”; and (b) not recorded on the test report form, the test shall be recorded as “failed”.

8.2 RP and RPF backflow preventers 8.2.1 General
To be recorded as “passed”, RP and RPF backflow preventers shall comply with the test requirements of Clauses 8.2.2 to 8.2.5. If “failed” is recorded in one or more of the tests, the backflow preventer shall be recorded as “failed”. The test results shall be recorded as specified in Clause 4.3.1 (see Table 1).

8.2.2 Relief valve 8.2.2.1 Requirements
The relief valve shall open at a minimum pressure differential of 13.8 kPa for an RP backflow preventer or 6.9 kPa for an RPF backflow preventer, as measured across check valve 1.

8.2.2.2 Pass/fail criteria
If the relief valve opens at a pressure differential of 13.8 kPa or greater for an RP backflow preventer or 6.9 kPa for an RPF backflow preventer across check valve 1, the test shall be recorded as a “pass”, and the relief valve opening pressure shall be recorded (“Opened at ___ kPa”). If the relief valve does not open or opens below a pressure differential of 13.8 kPa for an RP backflow preventer or 6.9 kPa for an RPF backflow preventer, as measured across check valve 1, the test shall be recorded as “failed”, and the relief valve opening pressure shall be recorded (“Opened at ___ kPa”).

8.2.3 Check valve 1 8.2.3.1 Requirements 8.2.3.1.1
Check valve 1 (upstream) shall close tight in the direction of flow, holding a differential pressure for a minimum period of 2 min or until the gauge reading stabilizes.

8.2.3.1.2
The differential pressure across check valve 1 shall be a minimum of 20.7 kPa higher than the opening pressure of the relief valve. This requirement shall not apply to RPF backflow preventers.

8.2.3.2 Pass/fail criteria 8.2.3.2.1
If check valve 1 closes tight in the direction of flow, holding a differential pressure for a minimum period of 2 min or until the gauge reading stabilizes, the test shall be recorded as “passed/closed tight”. If check valve 1 does not close tight in the direction of flow, holding a differential pressure for a minimum period of 2 min or until the gauge reading stabilizes, the test shall be recorded as “leaked/failed”.

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8.2.3.2.2
For RP backflow preventers only, if the differential pressure across check valve 1 is at least 20.7 kPa higher than the opening pressure of the relief valve, the test shall be recorded as “passed”. If the differential pressure across check valve 1 is less than 20.7 kPa higher than the opening pressure of the relief valve, the test shall be recorded as “failed”.

8.2.4 Check valve 2
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8.2.4.1 Requirements
Check valve 2 (downstream) shall close tight in the reverse direction of flow, holding a differential pressure for a minimum period of 2 min or until the gauge reading stabilizes.

8.2.4.2 Pass/fail criteria
If check valve 2 closes tight in the reverse direction of flow, holding a differential pressure for a minimum period of 2 min or until the gauge reading stabilizes, the test shall be recorded as “closed tight/passed”. If check valve 2 does not close tight in the reverse direction of flow, holding a differential pressure for a minimum period of 2 min or until the gauge reading stabilizes, the test shall be recorded as “leaked/failed”.

8.2.5 Static line pressure 8.2.5.1 Requirements
The static inlet line pressure shall be measured at the time of the test and recorded on the test report form.

8.2.5.2 Pass/fail criteria
If the static inlet line pressure at the time of the test is recorded on the test report form, the test shall be recorded as “passed”. If the static inlet line pressure at the time of the test is not recorded on the test report form, the test shall be recorded as “failed”.

8.3 DCVA, DCVAF, and SCVAF backflow preventers 8.3.1 General
To be recorded as “passed”, DCVA, DCVAF, and SCVAF backflow preventers shall comply with the test requirements of Clauses 8.3.2 to 8.3.4. If “failed” is recorded in one or more of the tests, the backflow preventer shall be recorded as “failed”. The test results shall be recorded as specified in Clause 4.3.1 (see Table 1).

8.3.2 Check valve 1 8.3.2.1 Requirements
Check valve 1 shall close tight in the direction of flow for a minimum period of 2 min or until the gauge reading stabilizes, when there is a differential pressure across the check valve with the (a) inlet pressure 6.9 kPa higher than the outlet pressure for DCVA and SCVAF backflow preventers; or (b) inlet pressure 3.45 kPa higher than the outlet pressure for DCVAF backflow preventers.

8.3.2.2 Pass/fail criteria
If check valve 1 complies with the requirements of Clause 8.3.2.1, the test shall be recorded as “closed tight/passed”. If check valve 1 does not comply with the requirements of Clause 8.3.2.1, the test shall be recorded as “leaked/failed”.

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Maintenance and field testing of backflow preventers

8.3.3 Check valve 2 8.3.3.1 Requirements
Check valve 2 shall close tight in the direction of flow for a period of 2 min or until the gauge reading stabilizes, when there is a differential pressure across the check valve with the (a) inlet pressure 6.9 kPa higher than the outlet pressure for DCVA backflow preventers; or (b) inlet pressure 3.45 kPa higher than the outlet pressure for DCVAF backflow preventers.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

8.3.3.2 Pass/fail criteria
If check valve 2 satisfies the requirements of Clause 8.3.3.1, the test shall be recorded as “closed tight/passed”. If check valve 2 does not satisfy the requirements of Clause 8.3.3.1, the test shall be recorded as “leaked/failed”.

8.3.4 Static line pressure 8.3.4.1 Requirements
The static inlet line pressure shall be taken at the time of the test and recorded on the test report form.

8.3.4.2 Pass/fail criteria
If the static inlet line pressure at the time of the test is recorded on the test report form, the test shall be recorded as “passed”. If the static inlet line pressure at the time of the test is not recorded on the test report form, the test shall be recorded as “failed”.

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Table 1 Field test requirements for backflow preventers
(See Clauses 8.1.1, 8.2.1, 8.3.1, and 8.5.1.)
Tests required Type of backflow preventer DCVA Check valve 1 buffer N/A Relief or air inlet required opening pressure N/A

Check valve 1 Hold a 6.9 kPa differential in direction of flow Hold a 3.4 kPa differential in direction of flow Hold a 6.9 kPa differential in direction of flow Hold tight with a differential in direction of flow Hold tight with a differential in direction of flow Hold a 6.9 kPa differential in direction of flow

Check valve 2 Hold a 6.9 kPa differential in direction of flow Hold a 3.4 kPa differential in direction of flow N/A

Record line pressure Yes

DCVAF

N/A

Yes

PVB/SRPVB

N/A

Before a 6.9 kPa differential Before a 13.8 kPa differential Before a 6.9 kPa differential N/A

Yes

Hold tight with a differential in reverse direction of flow Hold tight with a differential in reverse direction of flow N/A

20.7 kPa

Yes

RPF

N/A

Yes

SCVAF

N/A

Yes

Notes: (1) This Table provides a condensed version of the tests required. For the complete requirements, see Clauses 8.1, 8.2, and 8.3. (2) N/A means not applicable.

8.4 HCDVB devices — Manual field test of downstream check valve 8.4.1 Test requirement
When a back pressure equivalent to 3 m of head pressure is applied to the downstream check valve of an HCDVB device, it shall not allow leakage from the atmospheric vent exceeding 6 s in duration (this is normal and indicates proper operation). Continuous leakage exceeding 6 s at the atmospheric vent indicates that the downstream check valve is faulty and that the HCDVB device should be repaired or replaced.

8.4.2 Test set-up
With the HCDVB device in its normal operating position, as specified by the manufacturer, a hose shall be attached to its outlet.

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Maintenance and field testing of backflow preventers

8.4.3 Test procedure
The manual field test of the downstream check valve of an HCDVB device shall be conducted as follows: (a) Raise the hose until the end of the hose is at a height of 3 m. (b) Turn on the faucet or shut-off valve upstream of the specimen and let water run to fill the hose and purge any trapped air. (c) Turn off the faucet or shut-off valve and follow the manufacturer’s instructions to operate or open the atmospheric vent and reduce the pressure between the check valves to atmospheric, and then return the check valves to their normal operating position. (d) Maintain the hose at a height of 3 m for 5 min while observing the atmospheric vent for leakage.

8.5 SRPVB devices 8.5.1 General
To be recorded as “passed”, an SRPVB device shall comply with the test requirements of Clauses 8.5.2 to 8.5.4. If “failed” is recorded in one or more of these tests, the SRPVB device shall be recorded as “failed”. The test results shall be recorded as specified in Clause 4.3.1 (see Table 1).

8.5.2 Air inlet valve 8.5.2.1 Requirements
The air inlet valve shall begin to open when the internal pressure in the valve is 6.9 kPa or more above atmospheric pressure and shall be fully open when the water drains from the body of the SRPVB device.

8.5.2.2 Pass/fail criteria
If the air inlet valve begins to open when the internal pressure in the valve is 6.9 kPa or more above atmospheric pressure and is fully open when the water drains from the body, the test shall be recorded as ”opened/passed”. If one or both of the requirements are not met, the test shall be recorded as “failed to open/failed”.

8.5.3 Check valve 8.5.3.1 Requirements
The check valve shall close tight in the direction of flow for a minimum period of 2 min or until the gauge reading stabilizes, when the inlet pressure is a minimum of 6.9 kPa.

8.5.3.2 Pass/fail criteria
If the check valve closes tight in the direction of flow for a minimum period of 2 min or until the gauge reading stabilizes, when the inlet pressure is a minimum of 6.9 kPa, the test shall be recorded as “closed tight/passed”. If the check valve does not close tight for a minimum period of 2 min or until the gauge reading stabilizes, the test shall be recorded as ”leaked/failed”.

8.5.4 Static line pressure 8.5.4.1 Requirements
The static inlet line pressure test shall be measured at the time of the test and recorded on the test report form.

8.5.4.2 Pass/fail criteria
If the static inlet line pressure at the time of testing is (a) recorded on the test report form, the test shall be recorded as “passed”; and (b) not recorded on the test report form, the test shall be recorded as “failed”.

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Annex A (informative) Field testing procedures
Note: This informative (non-mandatory) Annex has been written in normative (mandatory) language to facilitate adoption where users of the Standard or regulatory authorities wish to adopt it formally as additional to the requirements in this Standard.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

A.1 PVB devices — Field testing using a differential pressure gauge
A.1.1 PVB devices — Testing procedures using a 3-valve differential pressure gauge A.1.1.1 Equipment required
Quantity 1 1 1 Description 3-valve differential pressure gauge Pressure gauge with a range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure Bleed valve with NPS-1/4 tee, 1/4 needle valve, 1/4 nipple, and IPS-1/4 flare adapter end

The tests specified in Clauses A.1.1.2 to A.1.1.5 shall be conducted using a 3-valve differential pressure gauge. To avoid damage to the gauge, it shall be gradually pressurized when using only one side of the gauge. The gauge and hoses (including hoses not used) shall be held at the same level as the PVB device being tested.

A.1.1.2 PVB devices — Test No. 1: Air inlet valve test A.1.1.2.1 Purpose
The purpose of the air inlet valve test is to test the operation of the air inlet valve of PVB devices.

A.1.1.2.2 Requirements
The requirements for the air inlet valve test for PVB devices are specified in Clause 8.1.2.

A.1.1.2.3 Procedure (see Figure A.1)
The air inlet valve test for PVB devices shall be conducted as follows: (a) Remove the atmospheric vent shield and conduct a physical examination of the PVB device to determine the condition of the air inlet valve and atmospheric vent. (b) Blow out the test cocks to remove any foreign material.
Notes: (1) Do not stand directly in front of the test cocks when turning them on or off; foreign material may be discharged or the test cocks may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

(c) Connect the hose to test cock 2, and gradually open test cock 2. (d) Open the high-pressure valve; then open the low-pressure valve and bleed the gauge and hoses. Close the low-pressure valve. (e) Close shut-off valve 2, then shut-off valve 1.

July 2007

Maintenance and field testing of backflow preventers

Gradually open the low-pressure valve, relieving pressure from the specimen and being careful not to drop the reading on the gauge too quickly. (g) Observe and note the gauge reading when the air inlet valve begins to open. (h) Completely open the low-pressure valve to drain the water from the specimen. (i) If the air inlet valve begins to open before the gauge reading drops below 6.9 kPa and is opened fully when the water is completely drained from the specimen, the test shall be recorded as “opened”. (ii) If the air inlet valve does not open or opens with a reading less than 6.9 kPa, the test shall be recorded as “failed to open/failed”. (i) Close the high-pressure valve, close the low-pressure valve, close test cock 2, and remove the gauge. (j) If the air inlet valve does not open, the gauge reading does not drop, and water continues to be discharged from the low-pressure valve, see Clause A.1.1.2.4.
High-pressure Differential pressure valve gauge Low-pressure valve

(f)

Atmospheric vent

Shield

Air inlet valve Test cock 2

Hose Shut-off valve 2 Check valve Shut-off valve 1

Test cock 1

Figure A.1 PVB devices — Test No. 1: Air inlet valve test
(See Clause A.1.1.2.3.)

July 2007

B64.10.1-07

A.1.1.2.4 Leaking shut-off valves (see Figure A.2)
If the low-pressure valve has to be opened more than one-quarter of the fully open position, it is likely that shut-off valve 1 is leaking and the following procedure shall be used: (a) To get a better seal, reopen and close shut-off valve 1. (b) If the leak persists, divert the leak so that the air inlet valve can be tested. (c) To redirect the leakage from shut-off valve 1, gradually open test cock 1, monitoring the gauge until its reading stabilizes. (d) Once the leakage has been diverted through test cock 1, resume testing at Item (f) of Clause A.1.1.2.3. (e) If the air inlet valve does not open and the leak through shut-off valve 1 exceeds the limit of test cock 1, repair or replace shut-off valve 1 before continuing with the test.
High-pressure valve Differential pressure gauge Low-pressure valve

Atmospheric vent

Shield

Air inlet valve

Test cock 2 Hose

Test cock 1

Shut-off valve 2 Check valve

Shut-off valve 1

Figure A.2 PVB devices — Leaking shut-off valve 1: Air inlet valve test
(See Clause A.1.1.2.4.)

July 2007

Maintenance and field testing of backflow preventers

A.1.1.3 PVB devices — Test No. 2: Check valve test A.1.1.3.1 Purpose
The purpose of the check valve test is to determine whether the check valve of PVB devices will close tight in the direction of flow.

A.1.1.3.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the check valve test for PVB devices are specified in Clause 8.1.3.

A.1.1.3.3 Procedure (see Figure A.3)
The check valve test for PVB devices shall be conducted as follows: (a) Open shut-off valve 1 to re-establish pressure in the PVB device. (b) Connect the hose to test cock 1 and gradually open test cock 1. (c) Open the high-pressure valve; then open the low-pressure valve and bleed the gauge and hoses. Close the gauge low valve. (d) Close shut-off valve 1 (shut-off valve 2 should still be closed from the air inlet valve test). (e) Open test cock 2, reducing the downstream side of the check valve to atmospheric pressure. (f) When the water stops flowing from test cock 2, (i) if the gauge reading has stabilized at 6.9 kPa or greater, record that the check valve “closed tight”; (ii) if the gauge reading drops to 0 kPa, or stabilizes at less than 6.9 kPa, record that the check valve “leaked/failed”; or (iii) if water continues to flow from test cock 2, see Clause A.1.1.3.4. (g) Close test cocks 1 and 2 and remove the pressure gauge. (h) Open shut-off valve 1, then open shut-off valve 2. (i) Reinstall the atmospheric vent shield.
Atmospheric vent Shield

High-pressure valve Differential pressure gauge

Low-pressure valve

Air inlet valve

Test cock 2
15

Test cock 1 Hose Shut-off valve 1

Shut-off valve 2 Check valve

Figure A.3 PVB devices — Test No. 2: Check valve test
(See Clause A.1.1.3.3.)

July 2007

B64.10.1-07

A.1.1.3.4 Leaking shut-off valves (see Figure A.4)
If water continues to flow from test cock 2 during Item (e) of Clause A.1.1.3.3, shut-off valve 1 is leaking and the following procedure shall be used: (a) Close test cock 1 and remove the hose. (b) Connect the bleed valve to test cock 1 and reconnect the hose. (c) Open test cock 1 (test cock 2 should still be open from the check valve test). (d) Gradually open the bleed valve until the water flow from test cock 2 is reduced to a slight drip. (e) Observe the reading on the gauge as the static pressure drop across the check valve decreases. (i) If the water flow ceases through test cock 2 and if the gauge reading has stabilized at 6.9 kPa or greater, record that the check valve “closed tight”. (ii) If the water flow from test cock 2 cannot be eliminated by opening the bleed valve, do not attempt to determine the tightness of the check valve until shut-off valve 1 is repaired or replaced.
Atmospheric vent

Shield

High-pressure valve Differential pressure gauge

Test cock 2 Low-pressure valve Test cock 1

Air inlet valve

Bleed valve Hose Shut-off valve 1

Shut-off valve 2 Check valve

Figure A.4 PVB devices — Leaking shut-off valve 1: Check valve test
(See Clause A.1.1.3.4.)

July 2007

Maintenance and field testing of backflow preventers

A.1.1.4 PVB devices — Test No. 3: Static line pressure test A.1.1.4.1 Purpose
The purpose of the static line pressure test is to determine the static inlet line pressure upstream of the check valve of a PVB device.

A.1.1.4.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the static line pressure test for PVB devices are specified in Clause 8.1.4.

A.1.1.4.3 Procedure (see Figure A.5)
The static line pressure test for PVB devices shall be conducted as follows: (a) Connect the pressure gauge to test cock 1. (b) Open test cock 1 and bleed the gauge to remove the air. (c) Observe and record the pressure reading on the test report form. (d) If the static inlet line pressure at the time of the test is not recorded on the test report form, record the test result as “failed”. (e) Close test cock 1 and remove the gauge.
Pressure gauge

Shield

40 30 20 10 0

60 70 80 90 100

Atmospheric vent

Air inlet valve Test cock 2

Hose Test cock 1

Shut-off valve 2 Check valve

Shut-off valve 1

Figure A.5 PVB devices — Test No. 3: Static line pressure test
(See Clause A.1.1.4.3.)

July 2007

B64.10.1-07

A.1.1.5 Returning PVB devices to service
After completing the tests specified in Clauses A.1.1.2 to A.1.1.4, PVB devices shall be returned to service as follows: (a) Close all test cocks. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the PVB device for leaks. (e) Inform the regulatory authority that the water supply is ready to be turned on. (f) Open shut-off valve 2, putting the PVB device back into service.

A.1.2 PVB devices — Testing procedures using a 5-valve differential pressure gauge A.1.2.1 Equipment required
Quantity 1 1 1 Description 5-valve differential pressure gauge Pressure gauge with a range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure Bleed valve with NPS-1/4 tee, 1/4 needle valve, 1/4 nipple, and IPS-1/4 flare adapter end

The tests specified in Clauses A.1.2.2 to A.1.2.5 shall be conducted using a 5-valve differential pressure gauge. To avoid damage to the gauge, it shall be gradually pressurized when using only one side of the gauge. The gauge and hoses (including hoses not used) shall be removed or held at the same level as the PVB device being tested.

A.1.2.2 PVB devices — Test No. 1: Air inlet valve test A.1.2.2.1 Purpose
The purpose of the air inlet valve test is to test the operation of the air inlet valve of PVB devices.

A.1.2.2.2 Requirements
The requirements for the air inlet valve test for PVB devices are specified in Clause 8.1.2.

A.1.2.2.3 Procedure (see Figure A.6)
The air inlet valve test for PVB devices shall be conducted as follows: (a) Remove the atmospheric vent shield and conduct a physical examination of the PVB device to determine the condition of the air inlet valve and atmospheric vent. (b) Blow out the test cocks to remove any foreign material.
Notes: (1) Do not stand directly in front of the test cocks when turning them on or off; foreign material may be discharged or the test cocks may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

(c) Connect the hose to test cock 2 and gradually open test cock 2. (d) Bleed the gauge and hoses as follows: (i) open the high-pressure valve; (ii) bleed the gauge and hoses; and (iii) close the high-pressure valve. (e) Close shut-off valve 2 and then close shut-off valve 1. (f) Gradually open the high-pressure valve, relieving pressure from the PVB device and being careful not to drop the reading on the gauge too quickly.

July 2007

Maintenance and field testing of backflow preventers

(g) Observe and note the gauge reading when the air inlet valve begins to open. (h) Completely open the high-pressure valve to drain the water from the body of the PVB. (i) If the air inlet valve begins to open before the gauge reading drops below 6.9 kPa and is fully open when the water is completely drained from the body, the test shall be recorded as “opened/passed”. (ii) If the air inlet valve does not open or opens with a reading less than 6.9 kPa, the test shall be recorded as “failed to open/failed”. (i) Close the high-pressure valve, then close test cock 2 and remove the gauge. (j) If the air inlet valve does not open, the gauge reading does not drop, and water continues to discharge from the low-pressure valve, see Clause A.1.2.2.4.
Differential pressure gauge High-pressure valve Low-pressure valve Atmospheric vent Shield

6 5 4 3 2 1 0

9 10 11 12 13 14 15

Air inlet valve

Test cock 2 Lowpressure inlet Test cock 1 Hose Shut-off valve 1 Shut-off valve 2 Check valve

High-pressure inlet

Bypass

Figure A.6 PVB devices — Test No. 1: Air inlet valve test
(See Clause A.1.2.2.3.)

July 2007

B64.10.1-07

A.1.2.2.4 Leaking shut-off valves (see Figure A.7)
If the high-pressure valve has to be opened more than one-quarter of the fully open position, it is likely that shut-off valve 1 is leaking and the following procedure shall be used: (a) To get a better seal, reopen and close shut-off valve 1. (b) If the leak persists, divert the leak so that the air inlet valve can be tested. (c) To redirect the leakage from shut-off valve 1, gradually open test cock 1, monitoring the gauge until its reading stabilizes. (d) Once the leakage has been diverted through test cock 1, testing may be resumed at Item (f) of Clause A.1.2.2.3. (e) If the air inlet valve does not open and the leak through shut-off valve 1 exceeds the limit of test cock 1, repair or replace shut-off valve 1 before continuing with the test.
Differential pressure gauge High-pressure valve Low-pressure valve Atmospheric vent Shield

6 5 4 3 2 1 0

9 10 11 12 13 14 15

Air inlet valve

Test cock 2 Lowpressure inlet Test cock 1 Shut-off valve 2 Check valve Shut-off valve 1

High-pressure inlet

Bypass

Hose

Figure A.7 PVB devices — Leaking shut-off valve 1: Air inlet valve test
(See Clause A.1.2.2.4.)

July 2007

Maintenance and field testing of backflow preventers

A.1.2.3 PVB devices — Test No. 2: Check valve test A.1.2.3.1 Purpose
The purpose of the check valve test is to determine whether the check valve of a PVB device will close tight in the direction of flow.

A.1.2.3.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the check valve test for PVB devices are specified in Clause 8.1.3.

A.1.2.3.3 Procedure (see Figure A.8)
The check valve test for PVB devices shall be conducted as follows: (a) Open shut-off valve 1 to re-establish pressure in the PVB device. (b) Connect the hose to test cock 1 and gradually open test cock 1. (c) Open the high-pressure valve and bleed the gauge and hose. Close the high-pressure valve. (d) Close shut-off valve 1 (shut-off valve 2 should still be closed from the air inlet valve test). (e) Open test cock 2, reducing the downstream side of the check valve to atmospheric pressure. (f) When the water stops flowing from test cock 2, (i) if the gauge reading has stabilized at 6.9 kPa or greater, record that the check valve “closed tight/passed”; (ii) if the gauge reading drops to 0 kPa or stabilizes at less than 6.9 kPa, record that the check valve “leaked/failed”; or (iii) if water continues to flow from test cock 2, see Clause A.1.2.3.4. (g) Close test cocks 1 and 2 and remove the gauge. (h) Open shut-off valve 1, then open shut-off valve 2. (i) Reinstall the atmospheric vent shield.
Atmospheric vent Differential pressure gauge High-pressure valve Low-pressure valve Test cock 2
6 5 4 3 2 1 0 15 7 8 9 10 11 12 13 14

Shield

Air inlet valve

Test cock 1 Lowpressure inlet Hose Shut-off valve 1

Shut-off valve 2 Check valve

High-pressure inlet

Bypass

Figure A.8 PVB devices — Test No. 2: Check valve test
(See Clause A.1.2.3.3.)

July 2007

B64.10.1-07

A.1.2.3.4 Leaking shut-off valves (see Figure A.9)
If water continues to flow from test cock 2 during Item (e) of Clause A.1.2.3.3, shut-off valve 1 is leaking and the following procedure shall be used: (a) Close test cock 1 and remove the hose from the gauge. (b) Connect the bleed valve to test cock 1 and reconnect the hose. (c) Open test cock 1 (test cock 2 should still be open from the check valve test). (d) Gradually open the bleed valve until the water flow from test cock 2 is reduced to a slight drip. (e) Observe the reading on the gauge as the static pressure drop across the check valve decreases. (f) If the water flow ceases through test cock 2, and if the gauge reading has stabilized at 6.9 kPa or greater, record that the check valve “closed tight”. (g) If the water flow from test cock 2 cannot be eliminated by opening the bleed valve, do not attempt to determine the tightness of the check valve until shut-off valve 1 is repaired or replaced.
Atmospheric vent Differential pressure gauge High-pressure valve Low-pressure valve Test cock 1
6 5 4 3 2 1 0 15 7 8 9 10 11 12 13 14

Shield

Test cock 2 Air inlet valve

Shut-off valve 2 Lowpressure inlet Hose Bleed valve Shut-off valve 1 Check valve

High-pressure inlet

Bypass

Figure A.9 PVB devices — Leaking shut-off valve 1: Check valve test
(See Clause A.1.2.3.4.)

July 2007

Maintenance and field testing of backflow preventers

A.1.2.4 PVB devices — Test No. 3: Static line pressure A.1.2.4.1 Purpose
The purpose of the static line pressure test is to determine the static inlet line pressure upstream of the check valve of a PVB device.

A.1.2.4.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the static line pressure test for PVB devices are specified in Clause 8.1.4.

A.1.2.4.3 Procedure (see Figure A.10)
The static line pressure test for PVB devices shall be conducted as follows: (a) Connect the pressure gauge to test cock 1. (b) Open test cock 1 and bleed the gauge to remove the air. (c) Observe the pressure reading and record it on the test report form. If the static inlet line pressure at the time of test is not recorded on the test report form, record the test result as “failed”. (d) Close test cock 1 and remove the gauge.
Pressure gauge Shield

40 30 20 10 0

60 70 80 90 100

Atmospheric vent Air inlet valve Test cock 2

Hose Test cock 1

Shut-off valve 2 Check valve

Shut-off valve 1

Figure A.10 PVB devices — Test No. 3: Static line pressure test
(See Clause A.1.2.4.3.)

July 2007

B64.10.1-07

A.1.2.5 Returning PVB devices to service
After completing the tests specified in Clauses A.1.2.2 to A.1.2.4, PVB devices shall be returned to service as follows: (a) Close all test cocks. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the PVB device for leaks. (e) Inform the regulatory authority in charge that the water supply is ready to be turned on. (f) Open shut-off valve 2, putting the PVB device back into service.

A.2 PVB devices — Field testing using the sight tube method
A.2.1 Equipment required
Quantity 1 2 1 2 1 Description Clear plastic tube (NPS-3/4 ID recommended) 900 mm long, complete with the necessary brass fittings and drain valve to allow it to be attached to a NPS-1/8 or NPS-1/4 female fitting NPS-1/4 IP to NPS-1/4 flare adapters Pressure gauge with a range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure Adapter fittings for each test cock, NPS-1/8 or NPS-1/4 female fitting Bleed valve with NPS-1/4 tee, 1/4 needle valve, 1/4 nipple, and IPS-1/4 flare adapter end

A.2.2 PVB devices — Test No. 1: Air inlet valve test A.2.2.1 Purpose
The purpose of the air inlet valve test is to test the operation of the air inlet valve of a PVB device.

A.2.2.2 Requirements
The requirements for the air inlet valve test for PVB devices are specified in Clause 8.1.2.

A.2.2.3 Procedure (see Figure A.11)
The air inlet valve test for PVB devices shall be conducted as follows: (a) Remove the atmospheric vent shield and conduct a physical examination of the PVB device to determine the condition of the air inlet valve and atmospheric vent. (b) Blow out the test cocks to remove any foreign material.
Notes: (1) Do not stand directly in front of the test cocks when turning them on or off; foreign material may be discharged or the test cocks may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

(c) Install the sight tube on test cock 2. (d) Open test cock 2, fill the sight tube to within 50 mm of the top (865 mm above the centreline of the air inlet valve seat), and then close test cock 2. (e) Mark the sight tube at 711 mm (equivalent to 6.9 kPa) above the centreline of the air inlet valve seat. (f) Close shut-off valve 2, then shut-off valve 1, and wait for 2 min. (g) If the air inlet valve opens at this time, it is an indication that shut-off valve 2 is leaking and should be repaired if the test cannot be continued.

July 2007

Maintenance and field testing of backflow preventers

(h) Open test cock 2, and if the air inlet valve does not open at this time, gradually open the drain valve to drain the water from the sight tube. (i) Watch the changing water level in the sight tube and observe when the air inlet valve opens. (j) If the air inlet valve (i) begins to open at or above the 711 mm mark and is fully open when the water drains from the body, record the test as “opened”; or (ii) opens below the 711 mm mark, record the test as “failed to open/failed”. (k) Close test cock 2 and remove the sight tube. (l) If the air inlet valve does not open when test cock 2 and the drain valve are open and water continues to be discharged through the drain valve, or water continues to rise in the sight tube, shut-off valve 1 could be leaking. See Figure A.12 and Clause A.2.2.4.

Sight tube

711 mm

Atmospheric port

Shield

Air inlet valve Test cock 2 Drain valve

Test cock 1 Shut-off valve 2 Check valve

Shut-off valve 1

Figure A.11 PVB devices — Test No. 1: Air inlet valve test
(See Clause A.2.2.3.)

July 2007

B64.10.1-07

A.2.2.4 Leaking shut-off valves (see Figure A.12)
If the conditions described in Item (l) of Clause A.2.2.3 occur, the following procedure shall be used: (a) To get a better seal, reopen and close shut-off valve 1. (b) If the leak persists, divert the leak so that the air inlet valve can be tested. (c) To redirect the leakage from shut-off valve 1, gradually open test cock 1, monitoring and maintaining the water level in the sight tube. (d) Once the leakage has been diverted through test cock 1, resume testing at Item (e) of Clause A.2.2.3. (e) If the leak through shut-off valve 1 exceeds the limit of the test cock 1, repair or replace shut-off valve 1 before continuing with the test.

Sight tube

711 mm

Atmospheric vent

Shield

Air intake valve Test cock 2

Drain valve

Test cock 1 Check valve

Shut-off valve 2

Shut-off valve 1

Figure A.12 PVB devices — Leaking shut-off valve 1: Air inlet valve test
(See Clause A.2.2.4.)

July 2007

Maintenance and field testing of backflow preventers

A.2.3 PVB devices — Test No. 2: Check valve test A.2.3.1 Purpose
The purpose of the check valve test is to determine whether the check valve of a PVB device will close tight in the direction of flow.

A.2.3.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the check valve test for PVB devices are specified in Clause 8.1.3.

A.2.3.3 Procedure (see Figure A.13)
The check valve test for PVB devices shall be conducted as follows: (a) Open shut-off valve 1 to re-establish pressure in the PVB device. (b) Connect the sight tube to test cock 1. (c) Open test cock 1 and fill the sight tube to a minimum height of 711 mm above test cock 2, then close test cock 1. (d) Close shut-off valve 1. (e) Open test cock 2, reducing the downstream side of the check valve to atmospheric pressure. (f) If water continues to flow from test cock 2, see Clause A.2.3.4. (g) Open test cock 1. (h) Observe the water level in the sight tube. (i) If the water level in the sight tube holds steady at or higher than the 711 mm mark for a period of 2 min, record that the check valve “closed tight” in the direction of flow. (ii) If the water level is not maintained at 711 mm, record that the check valve “leaked/failed” in the direction of flow. (iii) If the sight tube is filled to a height greater than 711 mm above test cock 2 and the water level in the sight tube drops, do not record that the check valve failed in the direction of flow until the water level drops below 711 mm. The water level should first be lowered to the 711 mm mark. If it continues to drop, record that the check valve “leaked/failed”. (iv) If the water level in the sight tube holds at 711 mm, record that the check valve “closed tight”. (i) Record the test results on the test report form. (j) Close test cocks 1 and 2, remove the sight tube, and reinstall the atmospheric vent shield.

July 2007

94
711 mm Drain valve Test cock 2 Test cock 1 Shut-off valve 1 Sight tube Atmospheric vent

B64.10.1-07

Figure A.13 PVB devices — Test No. 2: Check valve test
Check valve Air inlet valve Shut-off valve 2

(See Clause A.2.3.3.)

Shield

July 2007

Maintenance and field testing of backflow preventers

A.2.3.4 Leaking shut-off valves (see Figure A.14)
If water continues to flow from test cock 2 during Item (e) of Clause A.2.3.3, shut-off valve 1 is leaking and the procedure below shall be followed: (a) Open test cock 1 (test cock 2 should still be open from the check valve test). (b) Gradually open the drain valve until the water flow from test cock 2 is reduced to a slight drip. (c) Observe and maintain the water level in the sight tube (a minimum height of 711 mm above test cock 2). (d) Once the leakage has been diverted through test cock 1, resume testing at Item (e) of Clause A.2.3.3. (e) If the leak through shut-off valve 1 exceeds the limit of test cock 1, then repair or replace shut-off valve 1 before continuing with the test.

Sight tube

711 mm

Atmospheric vent

Shield

Air inlet valve Test cock 2

Test cock 1 Drain valve Shut-off valve 1

Shut-off valve 2 Check valve

Figure A.14 PVB devices — Leaking shut-off valve 1: Check valve test
(See Clause A.2.3.4.)

July 2007

B64.10.1-07

A.2.4 PVB devices — Test No. 3: Static line pressure test A.2.4.1 Purpose
The purpose of the static line pressure test is to determine the static inlet line pressure upstream of the check valve of a PVB device.

A.2.4.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the static line pressure test for PVB devices are specified in Clause 8.1.4.

A.2.4.3 Procedure (see Figure A.15)
The static line pressure test for PVB devices shall be conducted as follows: (a) Open shut-off valve 1 to re-establish pressure in the valve. (b) Connect the pressure gauge to test cock 1. (c) Open test cock 1 and bleed the pressure gauge to remove the air. (d) Observe and record the pressure reading on the test report form. (e) If the static inlet line pressure at time of test is not recorded on the test report form, record this test as “failed”. (f) Close test cock 1 and remove the pressure gauge.
Pressure gauge Shield

40 30 20 10 0

60 70 80 90 100

Atmospheric vent Air inlet valve

Test cock 2

Hose Test cock 1 Check valve

Shut-off valve 2

Shut-off valve 1

Figure A.15 PVB devices — Test No. 3: Static line pressure test
(See Clause A.2.4.3.)

July 2007

Maintenance and field testing of backflow preventers

A.2.5 Returning PVB devices to service
After completing the tests specified in Clauses A.2.2 to A.2.4, PVB devices shall be returned to service as follows: (a) Close all test cocks. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the PVB device for leaks. (e) Inform the regulatory authority that the water supply is ready to be turned on. (f) Open shut-off valve 2, putting the PVB device back into service.

A.3 RP backflow preventers — Field testing using a differential pressure gauge
A.3.1 RP backflow preventers — Testing procedures using a 3-valve differential pressure gauge A.3.1.1 Equipment required
Quantity 1 1 Description 3-valve differential pressure gauge Pressure gauge with a range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure

The procedures specified in Clauses A.3.1.2 to A.3.1.4 shall be conducted using a 3-valve differential pressure gauge.

A.3.1.2 RP backflow preventers — Test No. 1: Relief valve test A.3.1.2.1 Purpose
The purpose of the relief valve test for RP backflow preventers is to test the operation of the relief valve and determine the pressure at which it will open.

A.3.1.2.2 Requirements
The requirements for the relief valve test for RP backflow preventers are specified in Clause 8.2.2.

A.3.1.2.3 Procedure (see Figure A.16)
The relief valve test for RP backflow preventers shall be conducted as follows: (a) Open test cock 4 to ensure flow through the RP backflow preventer. Next, (i) gradually open, flush, and gradually close each test cock, starting with test cock 1, then 2, and then 3, to remove any foreign material; and (ii) gradually close test cock 4.
Notes: (1) Do not stand directly in front of the test cocks when turning them on or off; foreign material may be discharged or the test cocks may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

(b) Connect the high-pressure hose to test cock 2. (c) Connect the low-pressure hose to test cock 3. (d) Open the bypass valve, gradually open test cock 3, then open the low-pressure valve and bleed the low-pressure side of the gauge (leave it discharging while proceeding to Item (e)).

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(e) Bleed the high-pressure side of the gauge as follows: (i) gradually open test cock 2; (ii) open the high-pressure valve; (iii) bleed the high-pressure side of the gauge; (iv) close the high-pressure valve; (v) close the low-pressure valve; and (vi) close the bypass valve.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Note: When performing these procedures, it is important that the tester does not cause the relief valve to discharge before Item (e)(vi).

(f)

Close shut-off valve 2 and observe the gauge reading. If the reading drops very low and the relief valve begins to discharge continuously, check whether valve 1 is leaking. Repair the valve before proceeding.
Note: This reading will be referenced as the “apparent reading”.

(g) Open the high-pressure valve; then slightly open (one-quarter of the fully open position or less) the low-pressure valve, bypassing water from the high-pressure side of the gauge through test cock 3 into the reduced pressure zone until the gauge reading begins to drop (it is important that the rate of drop be gradual). (h) Hold one hand below the relief port and observe the gauge reading drop. Record the pressure at which water starts to be discharged from the relief port. (i) If the gauge reading is 13.8 kPa or higher, record that the relief valve “opened” and record the gauge reading at the opening point. (ii) If the gauge reading is lower than 13.8 kPa, record that the relief valve “failed to open” at the required pressure. (iii) If the relief valve does not open after bypassing water from the high-pressure to the low-pressure side, it could indicate that either the relief valve is faulty or shut-off valve 2 is leaking. (1) If the relief valve is faulty, the differential pressure will drop to 0 kPa. (2) If shut-off valve 2 is leaking, the low-pressure valve will have to be opened more than one-quarter of the fully open position to decrease the gauge reading to the opening pressure of the relief valve. In this case, see Clause A.3.1.2.4. (i) Close the high- and low-pressure valves.
Note: If wide line pressure fluctuations are observed during this test, shut-off valve 1 may have to be closed before proceeding with the test. Open shut-off valve 1 upon completion of the test.

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High-pressure valve

Differential pressure gauge

Low-pressure valve Bypass valve

HI
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Hoses

Test cock 3 Test cock 4

Test cock 1 Check valve 2 Shut-off valve 1 Relief port Check valve 1 Test cock 2 Shut-off valve 2

Relief valve

Figure A.16 RP backflow preventers — Test No. 1: Relief valve test
(See Clause A.3.1.2.3.)

A.3.1.2.4 Leaking shut-off valves
If the low-pressure valve needs to be opened more than one-quarter of the fully open position to decrease the gauge reading to the opening pressure of the relief valve, shut-off valve 2 could be leaking and the following procedure shall be used: (a) To get a better seal, reopen and close shut-off valve 2. (b) If the gauge reading does not drop to the opening pressure of the relief valve, repair or replace shut-off valve 2.

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A.3.1.3 RP backflow preventers — Test No. 2: Check valve 2 test A.3.1.3.1 Purpose
The purpose of the check valve 2 test for RP backflow preventers is to determine whether check valve 2 will close tight.

A.3.1.3.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the check valve 2 test for RP backflow preventers are specified in Clause 8.2.4.

A.3.1.3.3 Procedure (see Figure A.17)
The check valve 2 test for RP backflow preventers shall be conducted as follows: (a) Open the high-pressure valve and then slightly open the bypass valve to bleed air from the bypass hose. (b) Connect the bypass hose to test cock 4, close the bypass valve, and then open test cock 4. (c) Slightly unthread the low-pressure hose from test cock 3 and bleed water from the gauge until the reading is equal to or above the apparent reading (see Item (f) of Clause A.3.1.2.3). Retighten the hose. (d) Open the bypass valve to allow water to flow from test cock 2 through the bypass and test cock 4 into the RP backflow preventer. (e) The gauge reading across check valve 1 should remain the same or decrease slightly from the previous reading in test No. 1. Maintain the gauge reading for a period of 2 min. (i) If the pressure differential remains the same, record that check valve 2 “closed tight” in the reverse direction of flow. (ii) If the pressure differential is not maintained and drops to the relief valve opening pressure, either check valve 2 is fouled or disc compression has led to the discharge. To determine the cause, use the following procedure: (1) Slightly loosen the low-pressure hose from test cock 3, allowing water to bleed out. (2) Tighten the low-pressure hose to test cock 3. (3) If the relief valve discharges again, record on the test report that check valve 2 “leaked” in the reverse direction of flow. (4) If, after tightening the low-pressure hose to test cock 3, the gauge reading settles above the relief valve opening pressure, record that check valve 2 “closed tight” in the reverse direction of flow. It was disc compression that originally caused the relief valve to discharge.

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Differential pressure gauge High-pressure valve
5
10

Low-pressure valve Bypass valve

Hoses

Test cock 3 Test cock 4

Test cock 1 Check valve 2 Shut-off valve 1 Relief port Check valve 1 Test cock 2 Shut-off valve 2

Relief valve

Figure A.17 RP backflow preventers — Test No. 2: Check valve 2 test
(See Clause A.3.1.3.3.)

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A.3.1.4 RP backflow preventers — Test No. 3: Check valve 1 test A.3.1.4.1 Purpose
The purpose of the check valve 1 test for RP backflow preventers is to determine whether check valve 1 will close tight in the direction of flow, and to record the static pressure drop across check valve 1.

A.3.1.4.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the check valve 1 test for an RP backflow preventer are specified in Clause 8.2.3.

A.3.1.4.3 Procedure (see Figure A.18)
The check valve 1 test for an RP backflow preventer shall be conducted as follows: (a) To re-establish the pressure across check valve 1, slightly unthread the low-pressure hose connection at test cock 3, allowing a small amount of water to bleed, until the gauge reading is equal to or above the apparent check valve 1 reading (see Item (f) of Clause A.3.1.2.3 and Figure A.18). Then retighten the hose connection. (b) Observe the gauge reading for 2 min or until the reading stabilizes. (c) Record the gauge reading (this reading is the actual static pressure drop across check valve 1). (i) If the gauge reading remains constant, record that check valve 1 “closed tight” in the direction of flow. (ii) If the pressure differential reading falls until the relief valve opens, record that check valve 1 “leaked” in the direction of flow. (d) Calculate the buffer between the static pressure drop across check valve 1 and the opening pressure of the relief valve. The buffer is the static pressure drop across check valve 1, minus the opening pressure of the relief valve. (e) Record the buffer on the test report form. (i) If the buffer is 20.7 kPa or greater, record the test as “passed”. (ii) If the buffer is less than 20.7 kPa, record the test as “failed”. (f) Close all test cocks and remove the gauge.

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Differential pressure gauge Low-pressure valve High-pressure valve
5
10

Bypass valve

Hoses

Test cock 3 Test cock 4

Test cock 1

Check valve 2 Relief port Shut-off valve 1 Check valve 1 Relief valve Test cock 2 Shut-off valve 2

Figure A.18 RP backflow preventers — Test No. 3: Check valve 1 test
(See Clause A.3.1.4.3.)

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A.3.1.5 RP backflow preventers — Test No. 4: Static line pressure test A.3.1.5.1 Purpose
The purpose of the static line pressure test for RP backflow preventers is to determine the static inlet pressure at the time of the test.

A.3.1.5.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the static line pressure test for RP backflow preventers are specified in Clause 8.2.5.

A.3.1.5.3 Procedure (see Figure A.19)
The static line pressure test for RP backflow preventers shall be conducted as follows: (a) Connect the pressure gauge to test cock 1. (b) Open test cock 1 and bleed the gauge. (c) Observe and record the pressure reading on the test report form. (d) If the static inlet line pressure at time of test is not recorded on the test report form, record this test as “failed”. (e) Close test cock 1, and remove the gauge.

Pressure gauge

Test cock 3 Test cock 4

40 30 20 10 0

60 70 80 90 100

Test cock 1

Check valve 1 Shut-off valve 1 Test cock 2

Check valve 2 Relief port Shut-off valve 2

Relief valve

Figure A.19 RP backflow preventers — Test No. 4: Static line pressure test
(See Clause A.3.1.5.3.)

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A.3.1.6 Returning RP backflow preventers to service
After completing the tests specified in Clauses A.3.1.2 to A.3.1.5, RP backflow preventers shall be returned to service as follows: (a) Close all test cocks. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the RP backflow preventer for leaks. (e) Inform the regulatory authority that the water is ready to be turned on. (f) Open shut-off valve 2, putting the RP backflow preventer back into service.

A.3.2 RP backflow preventers — Testing procedures using a 5-valve differential pressure gauge A.3.2.1 Equipment required
Quantity 1 1 Description 5-valve differential pressure gauge Pressure gauge with a range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure

The test procedures specified in Clauses A.3.2.2 to A.3.2.5 shall be conducted using a 5-valve differential pressure gauge.

A.3.2.2 RP backflow preventers — Test No. 1: Relief valve test A.3.2.2.1 Purpose
The purpose of the relief valve test for RP backflow preventers is to test the operation of the relief valve and determine the pressure at which it will open.

A.3.2.2.2 Requirements
The requirements for the relief valve test for RP backflow preventers are specified in Clause 8.2.2.

A.3.2.2.3 Procedure (see Figure A.20)
The relief valve test for RP backflow preventers shall be conducted as follows: (a) Open test cock 4 to ensure flow through the RP backflow preventer. (i) Gradually open, flush, and close each test cock, starting with test cock 1 and finishing with 3, to remove any foreign material. (ii) Gradually close test cock 4.
Notes: (1) Do not stand directly in front of the test cocks when turning them on or off; foreign material may be discharged or the test cocks may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

(b) Connect the high-pressure hose of the gauge to test cock 2. (c) Connect the low-pressure hose of the gauge to test cock 3. (d) Gradually open test cock 3, then open the low-pressure valve and bleed the low-pressure side of the gauge (leave it discharging while proceeding to Item (e)). (e) Bleed the high-pressure side of the gauge as follows: (i) gradually open test cock 2; (ii) open the high-pressure valve; (iii) bleed the high-pressure side of the gauge; (iv) close the high-pressure valve; and

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(v) close the low-pressure valve.
Note: When performing these procedures it is important that the tester does not cause the relief valve to discharge before Item (f).

(f)

(g) Open the high-pressure valve, then slightly open (one-quarter of the fully open position or less) the low-pressure valve, bypassing water from the high-pressure side of the gauge through test cock 3 into the zone of reduced pressure until the gauge reading begins to drop (it is important that the rate of drop be gradual). (h) Hold one hand below the relief port and observe the gauge reading drop. Record the gauge reading at the pressure at which water starts to be discharged from the relief port. (i) If the gauge reading is 13.8 kPa or higher, record that the relief valve “opened” and the gauge reading at the opening point. (ii) If the gauge reading is lower than 13.8 kPa, record that the relief valve “failed to open” at the required pressure. (iii) If the relief valve does not open after bypassing water from the high-pressure side to the low-pressure side, it could indicate that either the relief valve is faulty or that shut-off valve 2 is leaking. (1) If the relief valve is faulty, the differential pressure will drop to 0 kPa. (2) If shut-off valve 2 is leaking, the low-pressure valve will have to be more than one-quarter of the fully open position to lower the gauge reading to the relief valve opening pressure. In this case, see Clause A.3.2.2.4. (i) Close the high- and low-pressure valves.
Note: If wide fluctuations of line pressure are observed during this test, shut-off valve 1 may have to be closed before proceeding with the test. Open shut-off valve 1 upon completion of the test.

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Differential pressure gauge High-pressure valve
6 5 4 3 2 7 8 9 10 11 12 13 1 0 15 14

Low-pressure valve

Highpressure inlet Bypass valve Hoses

Low-pressure inlet

Test cock 3 Test cock 4

Test cock 1 Check valve 2 Shut-off valve 1 Check valve 1 Test cock 2 Relief port Shut-off valve 2

Relief valve

Figure A.20 RP backflow preventers — Test No. 1: Relief valve test
(See Clause A.3.2.2.3.)

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A.3.2.2.4 Leaking shut-off valves
If the low-pressure valve needs to be opened more than one-quarter of the fully open position to decrease the gauge reading to the relief valve opening pressure, shut-off valve 2 could be leaking and the following procedure shall be used: (a) To get a better seal, reopen and close shut-off valve 2. (b) If the gauge reading does not drop to the relief valve opening pressure, repair or replace shut-off valve 2.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

A.3.2.3 RP backflow preventers — Test No. 2: Check valve 2 test A.3.2.3.1 Purpose
The purpose of the check valve 2 test for RP backflow preventers is to determine whether check valve 2 will close tight.

A.3.2.3.2 Requirements
The requirements for the check valve 2 test for RP backflow preventers are specified in Clause 8.2.4.

A.3.2.3.3 Procedure (see Figure A.21)
The check valve test No. 2 for RP backflow preventers shall be conducted as follows: (a) Slightly open the bypass valve to bleed air from the bypass hose, then close the bypass valve. (b) Connect the bypass hose to test cock 4 and open test cock 4. (c) Open the low-pressure valve and relieve the excess pressure to re-establish the apparent pressure drop reading across check valve 1. Close the low-pressure valve. (d) Open the bypass valve to allow water to flow from test cock 2 through the bypass and from test cock 4 into the valve. (e) The gauge reading across check valve 1 should remain the same or decrease slightly from the previous reading in test No. 1. Maintain the gauge reading for a period of 2 min. (i) If the pressure differential remains the same, record that check valve 2 “closed tight” in the reverse direction of flow. (ii) If the pressure differential is not maintained and drops to the relief valve opening pressure, either check valve 2 is fouled or disc compression has led to the discharge. To determine the cause, use the following procedure: (1) Open the low-pressure valve to allow water to bleed. (2) Close the low-pressure valve. (3) If the relief valve discharges again, record on the test report that check valve 2 “leaked” in the reverse direction of flow. (4) If, after closing the low-pressure valve, the gauge reading settles above the relief valve opening pressure, record that check valve 2 “closed tight” in the reverse direction of flow. This indicates that disc compression originally caused the relief valve to discharge.

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Differential pressure gauge High-pressure valve
6 5 4 3 2 7 8 9 10 11 12 13 1 0 15 14

Low-pressure valve

Highpressure inlet Bypass valve

Low-pressure inlet

Hoses

Test cock 3

Test cock 4

Test cock 1 Check valve 2 Shut-off valve 1 Check valve 1 Relief port Shut-off valve 2

Test cock 2

Relief valve

Figure A.21 RP backflow preventers — Test No. 2: Check valve 2 test
(See Clause A.3.2.3.3.)

A.3.2.4 RP backflow preventers — Test No. 3: Check valve 1 test A.3.2.4.1 Purpose
The purpose of the check valve 1 test for RP backflow preventers is to determine whether check valve 1 will close tight in the direction of flow, and to record the static pressure drop across check valve 1.

A.3.2.4.2 Requirements
The requirements for the check valve 1 test for RP backflow preventers are specified in Clause 8.2.3.

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A.3.2.4.3 Procedure (see Figure A.22)
The check valve 1 test for RP backflow preventers shall be conducted as follows: (a) To re-establish the pressure across check valve 1, open the low-pressure valve, allowing a small amount of water to bleed, until the gauge reading is equal to or above the apparent check valve 1 reading (see Item (g) of Clause A.3.2.2.3). Close the low-pressure valve. (b) Observe the gauge reading for 2 min or until the reading stabilizes. (c) Record the gauge reading (this reading is the actual static pressure drop across check valve 1). (i) If the gauge reading remains constant, record that check valve 1 “closed tight” in the direction of flow. (ii) If the pressure differential reading falls until the relief valve opens, record that check valve 1 “leaked” in the direction of flow. (d) Calculate the buffer between the static pressure drop across check valve 1 and the opening pressure of the relief valve. The buffer is the static pressure drop across check valve 1 minus the opening pressure of the relief valve. (e) Record the buffer on the test report form. (i) If the buffer is 20.7 kPa or greater, record the test as “passed”. (ii) If the buffer is less than 20.7 kPa, record the test as “failed”. (f) Close all test cocks and remove the gauge.

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Maintenance and field testing of backflow preventers

Differential pressure gauge High-pressure valve
6 5 4 3 7 8 9 10 11 12 13 1 0 15 14

Low-pressure valve

Highpressure inlet Bypass valve

Low-pressure inlet

Hoses

Test cock 3

Test cock 4

Test cock 1 Check valve 2 Relief port Check valve 1

Shut-off valve 1

Shut-off valve 2

Relief valve Test cock 2

Figure A.22 RP backflow preventers — Test No. 3: Check valve 1 test
(See Clause A.3.2.4.3.)

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A.3.2.5 RP backflow preventers — Test No. 4: Static line pressure A.3.2.5.1 Purpose
The purpose of the static line pressure test for RP backflow preventers is to determine the static inlet pressure at the time of the test.

A.3.2.5.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the static line pressure test for RP backflow preventers are specified in Clause 8.2.5.

A.3.2.5.3 Procedure (see Figure A.23)
The static line pressure test for RP backflow preventers shall be conducted as follows: (a) Connect the pressure gauge to test cock 1. (b) Open test cock 1 and bleed the gauge. (c) Observe and record the pressure reading on the test report form. (d) If the static inlet line pressure at the time of the test is not recorded on the test report form, record the test as “failed”. (e) Close test cock 1 and remove the gauge.

Pressure gauge

Test cock 3 Test cock 4

40 30 20 10 0

60 70 80 90 100

Test cock 1

Check valve 1 Shut-off valve 1 Test cock 2

Check valve 2 Relief port Shut-off valve 2

Relief valve

Figure A.23 RP backflow preventers — Test No. 4: Static line pressure test
(See Clause A.3.2.5.3.)

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A.3.2.6 Returning the RP backflow preventer to service
After completing the tests specified in Clauses A.3.2.2 to A.3.2.5, RP backflow preventers shall be returned to service as follows: (a) Close all test cocks. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the RP backflow preventer for leaks. (e) Inform the regulatory authority that the water is ready to be turned on. (f) Open shut-off valve 2, putting the RP backflow preventer back into service.

A.4 DCVA backflow preventers — Testing procedures using the sight tube method
A.4.1 Equipment required
Quantity 1 1 1 2 1 1 Description Clear plastic tube (NPS-3/4 ID recommended) 900 mm long, complete with the necessary brass fittings and drain valve to allow it to be attached to an NPS-1/8 or NPS-1/4 female fitting NPS-1/2 × 1/4 brass bushing (used for testing NPS-2-1/2 to NPS-4 valves inclusive) NPS-3/4 × 1/4 brass bushing (used for testing NPS-6 and larger valves) NPS-1/4 IP to NPS-1/4 flare adapters Hose with flare adapter ends Pressure gauge with a range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure

A.4.2 DCVA backflow preventers — Test No. 1: Check valve 1 A.4.2.1 Purpose
The purpose of the check valve 1 test for DCVA backflow preventers is to determine if check valve 1 will close tight in the direction of flow and to measure the static pressure drop across check valve 1.

A.4.2.2 Requirements
The requirements for the check valve 1 test for DCVA backflow preventers are specified in Clause 8.3.2.

A.4.2.3 Procedure (see Figure A.24)
The check valve 1 test for DCVA backflow preventers shall be conducted as follows: (a) Blow out the test cocks to remove any foreign material.
Notes: (1) Do not stand directly in front of the test cocks when turning them on or off; foreign material may be discharged or the test cocks may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

(b) Install the sight tube on test cock 2. (c) Mark the sight tube at 711 mm above the centreline of test cock 3. If test cock 3 is below the centreline of the DCVA backflow preventer, take the 711 mm measurement from the centreline of the DCVA backflow preventer [see Figure A.24(a)]. (d) Open test cock 2 and fill the sight tube with water to the predetermined mark. Close test cock 2. (e) Close shut-off valve 2, then close shut-off valve 1.

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(f) Open test cock 2, then open test cock 3. (g) Observe the water level in the sight tube. (i) If the water level in the sight tube holds steady at a height of 711 mm for a period of 2 min, record that check valve 1 “closed tight” in the direction of flow. (ii) If the water level is not maintained at 711 mm, record that check valve 1 “leaked/failed” in the direction of flow. (iii) If the sight tube is filled to a level higher than 711 mm and the water level drops, do not record that check valve 1 “leaked/failed” in the direction of flow until the water level in the sight tube drops below the 711 mm mark. (iv) If the water level drops below the 711 mm mark, record that check valve 1 “leaked/failed” in the direction of flow. (v) If the water level in the sight tube rises, it indicates that shutoff valve 1 is leaking. Repair the shut-off valve before proceeding with the test. (h) Close test cock 3, close test cock 2, and then remove the sight tube.
Note: Figures A.24(a) and (b) illustrate alternative methods of measurement depending on the test cock location.

Sight tube

711 mm

Shut-off valve 1 Test cock 1

Test cock 2 Check valve 1

Test cock 3 Check valve 2

Test cock 4

Shut-off valve 2

(a) Test cocks located on the centreline

Figure A.24 DCVA backflow preventers — Test No. 1: Check valve 1 test
(See Clause A.4.2.3.)
(Continued)

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Sight tube

711 mm

Test cock 3 Test cock 4

Test cock 2

Shut-off valve 1

Check valve 1 Test cock 1

Check valve 2

Shut-off valve 2

(b) Test cocks located above the centreline

Figure A.24 (Concluded) A.4.3 DCVA backflow preventers — Test No. 2: Check valve 2 test A.4.3.1 Purpose
The purpose of the check valve 2 test for DCVA backflow preventers is to determine if check valve 2 will close tight in the direction of flow and to measure the static pressure drop across check valve 2.

A.4.3.2 Requirements
The requirements for the check valve 2 test for DCVA backflow preventers are specified in Clause 8.3.3.

A.4.3.3 Procedure (see Figure A.25)
The check valve 2 test for DCVA backflow preventers shall be conducted as follows: (a) Install the sight tube on test cock 3. (b) Mark the sight tube at 711 mm above the opening of test cock 4. If the downstream test cock is below the centreline of the DCVA backflow preventer, the 711 mm measurement shall be taken from the centreline of the DCVA backflow preventer [see Figure A.25(a)]. (c) Open shut-off valve 1, then open test cock 3 and fill the sight tube with water to the 711 mm mark. Close test cock 3. (d) Close shut-off valve 1. (e) Open test cock 3, then open test cock 4.

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Observe the water level in the sight tube. (i) If the water level in the sight tube holds steady at a height of 711 mm for a period of 2 min, record that check valve 2 “closed tight” in the direction of flow. (ii) If the water level is not maintained at a height of 711 mm, record that check valve 2 “leaked/failed” in the direction of flow. (iii) If the sight tube is filled to a level higher than 711 mm and the water level drops, do not record that check valve 2 “leaked/failed” in the direction of flow until the water level in the sight tube drops below the 711 mm mark. (iv) If the water level does drop below the 711 mm mark, record that check valve 2 “leaked/failed” in the direction of flow. (v) A continuous discharge of water from test cock 4, while the water level in the sight tube remains constant, indicates that shut-off valve 2 is leaking. This will only occur if there is back pressure in the piping system. Repair shut-off valve 2 before proceeding with the test. (g) Close test cock 4, close test cock 3, then remove the sight tube.
Note: Figures A.25(a) and (b) illustrate alternative methods of measurement depending on the test cock location.

(f)

Sight tube

711 mm Test cock 2

Test cock 1 Shut-off valve 1

Check valve 1

Test cock 3

Test cock 4

Shut-off valve 2

Check valve 2

(a) Test cocks located on the centreline

Figure A.25 DCVA backflow preventers — Test No. 2: Check valve 2 test
(See Clause A.4.3.3.)
(Continued)

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Sight tube

711 mm
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Test cock 4

Test cock 3

Test cock 2

Shut-off valve 1

Test cock 1

Check valve 1

Check valve 2

Shut-off valve 2

(b) Test cocks located above the centreline

Figure A.25 (Concluded) A.4.4 DCVA backflow preventers — Test No. 3: Static line pressure test A.4.4.1 Purpose
The purpose of the static line pressure test for DCVA backflow preventers is to determine the static inlet pressure at the time of the test.

A.4.4.2 Requirements
The requirements for the static line pressure test for DCVA backflow preventers are specified in Clause 8.3.4.

A.4.4.3 Procedure (see Figure A.26)
The static line pressure test for DCVA backflow preventers shall be conducted as follows: (a) Connect the pressure gauge to test cock 1. (b) Open test cock 1 and bleed the gauge. (c) Observe and record the pressure reading on the test report form. (d) If the static inlet line pressure at the time of test is not recorded on the test report form, record the test as “failed”. (e) Close test cock 1 and remove the gauge.

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Pressure gauge
40 30 20 10 0 50 60 70 80 90 100

Test cock 2

Shut-off valve 1

Test cock 1

Test cock 3 Check valve 1 Check valve 2

Test cock 4

Shut-off valve 2

Figure A.26 DCVA backflow preventers — Test No. 3: Static line pressure test
(See Clause A.4.4.3.)

A.4.5 Returning DCVA backflow preventers to service
After completing the tests specified in Clauses A.4.2 to A.4.4, DCVA backflow preventers shall be returned to service as follows: (a) Close all test cocks. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the DCVA backflow preventer for leaks. (e) Inform the regulatory authority that the water is ready to be turned on. (f) Open shut-off valve 2, putting the DCVA backflow preventer back into service.

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A.5 DCVA backflow preventers — Field testing of DCVA backflow preventers using a differential pressure gauge
A.5.1 DCVA backflow preventers — Testing procedures using a 3-valve differential pressure gauge
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

A.5.1.1 Equipment required
Quantity 1 1 1 1 Description 3-valve differential pressure gauge Clear plastic tube (NPS-3/4 ID is recommended) 900 mm long, complete with the necessary brass fittings and drain valve to allow it to be attached to an NPS-1/8 or NPS-1/4 female fitting Pressure gauge with range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure Bleed valve with NPS-1/4 tee, 1/4 needle valve, 1/4 nipple, and IPS-1/4 flare adapter end

The tests specified in Clauses A.5.1.2 to A.5.1.4 shall be conducted using a 3-valve differential pressure gauge. To avoid damage to the gauge, it shall be gradually pressurized when using only one side of the gauge. To obtain accurate readings, the gauge and hoses (including hoses not used) shall be held at the same level as the DCVA backflow preventer being tested.

A.5.1.2 DCVA backflow preventers — Test No. 1: Check valve 1 test for DCVA backflow preventers A.5.1.2.1 Purpose
The purpose of the check valve 1 test for DCVA backflow preventers is to determine whether check valve 1 will close tight in the direction of flow and to measure the static pressure drop across check valve 1.

A.5.1.2.2 Requirements
The requirements for the check valve 1 test for DCVA backflow preventers are specified in Clause 8.3.2.

A.5.1.2.3 Procedure (see Figure A.27)
The check valve 1 test for DCVA backflow preventers shall be conducted as follows: (a) Blow out the test cocks to remove any foreign material.
Notes: (1) Do not stand directly in front of the test cocks when turning them on or off; foreign material may be discharged or the test cocks may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

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(v) bleed the high-pressure side of the gauge; (vi) close the low-pressure valve; and (vii) close the high-pressure valve. (d) If the vertical tube is attached, open test cock 3 and fill the tube to the elevation that is level with the centreline of the gauge, then close test cock 3. (e) Close shut-off valve 2, then close shut-off valve 1. (f) Gradually open test cock 3; after water stops discharging from test cock 3 and the gauge stabilizes, observe the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record the value and that check valve 1 “closed tight”. (ii) If the gauge reading stabilizes at less than 6.9 kPa, record that check valve 1 “leaked/failed”. (g) Close all test cocks, open shut-off valve 1, and remove the gauge.
High-pressure valve

Differential pressure gauge
10

Low-pressure valve Vertical tube

Hoses Test cock 2

Water level to centreline of gauge

Test cock 3 Shut-off valve 1 Test cock 1 Bleed valve Check valve 1 Check valve 2 Shut-off valve 2 Test cock 4

Figure A.27 DCVA backflow preventers — Test No. 1: Check valve 1 test
(See Clauses A.5.1.2.3 and A.5.1.2.4.)

A.5.1.2.4 Leaking shut-off valves (see Figure A.27) A.5.1.2.4.1 Leaking shut-off valve 2 (with no pressure downstream)
If the water recedes (in the vertical tube) through test cock 3, lower the centreline of the gauge to the centreline of the DCVA backflow preventer and observe and record the gauge reading as follows: (a) If the reading is 6.9 kPa or greater, record that check valve 1 “closed tight”. (b) If the reading stabilizes at less than 6.9 kPa, record that (i) check valve 1 “leaked”; (ii) shut-off valve 2 “leaked”; and (iii) check valve 2 “leaked”.

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A.5.1.2.4.2 Leaking shut-off valves 1 and 2 (with pressure downstream)
If the water rises (in the vertical tube) through test cock 3, one of the shut-off valves could be leaking. Observe and note the gauge reading and use the following procedure: (a) Gradually open the bleed valve. (b) If water continues to flow through the bleed valve, and the bleed valve can be adjusted so there is only a slight rise (in the vertical tube) or a drip through test cock 3, observe and record the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record that check valve 1 “closed tight”. (ii) If the reading stabilizes at less than 6.9 kPa, record that (1) check valve 1 “leaked/failed”; and (2) shut-off valve 1 “leaked”. (c) If the water flow cannot be reduced sufficiently, repair or replace shut-off valve 1 before proceeding. (d) If water does not continue to flow through the bleed valve, yet continues to flow through test cock 3, observe and record the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record that check valve 1 “closed tight”. (ii) If the reading stabilizes at less than 6.9 kPa, record that (1) check valve 1 “leaked/failed”; (2) shut-off valve 2 “leaked”; and (3) check valve 2 “leaked”. (e) Advance to Item (f) of Clause A.5.1.2.3.

A.5.1.3 DCVA backflow preventers — Test No. 2: Check valve 2 test A.5.1.3.1 Purpose
The purpose of the check valve 2 test for DCVA backflow preventers is to determine whether check valve 2 will close tight in the direction of flow and to measure the static pressure drop across check valve 2.

A.5.1.3.2 Requirements
The requirements for the check valve 2 test for DCVA backflow preventers are specified in Clause 8.3.3.

A.5.1.3.3 Procedure (see Figure A.28)
The check valve 2 test for DCVA backflow preventers shall be conducted as follows: (a) To obtain proper readings from the gauge, locate it at the same elevation or level as the test cock downstream of check valve 2 (test cock 4). (i) If test cock 4 is the highest point of check valve 2, use the top of test cock 4 as a reference point, and advance to Item (b). (ii) If test cock 4 is not the highest point of check valve 2, install a vertical tube on test cock 4 so that it rises above the body of the DCVA backflow preventer. (b) Install the bleed valve on test cock 3. Then (i) connect the high-pressure hose to the bleed valve; (ii) gradually open test cock 3; (iii) open the high-pressure valve; (iv) open the low-pressure valve; (v) bleed the high-pressure side of the gauge; (vi) close the low-pressure valve; and (vii) close the high-pressure valve. (c) If the tube is attached, open test cock 4 and fill the tube to an elevation that is level with the centreline of the gauge; then close test cock 4. (d) With shut-off valve 2 still closed, close shut-off valve 1.

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(e) Gradually open test cock 4; after water stops discharging from test cock 4 and the gauge stabilizes, observe the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record the value of the reading and that check valve 2 “closed tight”. (ii) If the gauge reading stabilizes at less than 6.9 kPa, record that check valve 2 “leaked/failed”. (f) Close all test cocks, open shut-off valve 1, and remove the gauge.
Low-pressure valve
10

High-pressure valve Differential pressure gauge

Vertical tube
LO
15

Hose Bleed valve Water level to centreline of gauge

Test cock 4

Test cock 3 Test cock 2

Shut-off valve 1 Test cock 1

Check valve 1

Check valve 2

Shut-off valve 2

Figure A.28 DCVA backflow preventers — Test No. 2: Check valve 2 test
(See Clauses A.5.1.3.3 and A.5.1.3.4.)

A.5.1.3.4 Leaking shut-off valves (see Figure A.28) A.5.1.3.4.1 Leaking shut-off valve 2 (with no pressure downstream)
If the water recedes (in the vertical tube) or flows through test cock 4, lower the centreline of the gauge to the centreline of the DCVA backflow preventer and observe and record the gauge reading as follows: (a) If the reading is 6.9 kPa or greater, record that check valve 1 “closed tight”. (b) If the gauge reading stabilizes at less than 6.9 kPa, record that check valve 1 “leaked/failed” and shut-off valve 2 “leaked”.

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A.5.1.3.4.2 Leaking shut-off valves 1 and 2 (with pressure downstream)
If the water rises (in the vertical tube) or flows through test cock 4, one of the shut-off valves could be leaking. Observe and note the gauge reading and use the following procedure: (a) Gradually open the bleed valve. (b) If water continues to flow through the bleed valve, and the bleed valve can be adjusted so that there is only a slight rise (in the vertical tube) or a drip through test cock 4, observe and record the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record that check valve 2 “closed tight”. (ii) If the reading stabilizes at less than 6.9 kPa, record that check valve 2 “leaked/failed” and shut-off valve 1 “leaked”. (c) If water does not continue to flow through the bleed valve, yet continues to flow through test cock 4, observe and record the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record that check valve 2 “closed tight”. (ii) If the reading is less than 6.9 kPa, record that check valve 2 “leaked/failed” and shut-off valve 2 “leaked”.

A.5.1.4 DCVA backflow preventers — Test No. 3: Static line pressure test A.5.1.4.1 Purpose
The purpose of the static line pressure test for DCVA backflow preventers is to determine the static inlet pressure at the time of the test.

A.5.1.4.2 Requirements
The requirements for the static line pressure test for DCVA backflow preventers are specified in Clause 8.3.4.

A.5.1.4.3 Procedure (see Figure A.29)
The static line pressure test for DCVA backflow preventers shall be conducted as follows: (a) Connect the pressure gauge to test cock 1. (b) Open test cock 1 and bleed the gauge. (c) Observe and record the pressure reading on the test report form. (d) If the static inlet line pressure at time of test is not recorded on the test report form, record the test as “failed”. (e) Close test cock 1 and remove the gauge.

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Pressure gauge

40 30 20 10 0

60 70 80 90 100

Shut-off valve 1

Test cock 2 Test cock 1

Test cock 3 Check valve 1

Test cock 4 Check valve 2

Shut-off valve 2

Figure A.29 DCVA backflow preventers — Test No. 3: Static line pressure test
(See Clause A.5.1.4.3.)

A.5.1.5 Returning DCVA backflow preventers to service
After completing the tests specified in Clauses A.5.1.2 to A.5.1.4, DCVA backflow preventers shall be returned to service as follows: (a) Close all test cocks. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the DCVA backflow preventer for leaks. (e) Inform the regulatory authority that the water is ready to be turned on. (f) Open shut-off valve 2, putting the DCVA backflow preventer back into service.

A.5.2 DCVA backflow preventers — Testing procedures using a 5-valve differential pressure gauge A.5.2.1 Equipment required
Quantity 1 1 1 1 Description Clear plastic tube (NPS-3/4 ID is recommended) 900 mm long, complete with the necessary brass fittings and drain valve to allow it to be attached to an NPS-1/8 or NPS-1/4 female fitting 5-valve differential pressure gauge Pressure gauge with a range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure Bleed valve with NPS-1/4 tee, 1/4 needle valve, 1/4 nipple, and IPS-1/4 flare adapter end

The tests specified in Clauses A.5.2.2 to A.5.2.5 shall be conducted using a 5-valve differential pressure gauge. To avoid damage to the gauge, it shall be gradually pressurized when using only one side of the gauge. To obtain accurate readings, the gauge and hoses (including hoses not used) shall be removed or held at the same level as the DCVA backflow preventer being tested.

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A.5.2.2 DCVA backflow preventers — Test No. 1: Check valve 1 test A.5.2.2.1 Purpose
The purpose of the check valve 1 test for DCVA backflow preventers is to determine whether check valve 1 will close tight in the direction of flow and to measure the static pressure drop across check valve 1.

A.5.2.2.2 Requirements
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

The requirements for the check valve 1 test for DCVA backflow preventers are specified in Clause 8.3.2.

A.5.2.2.3 Procedure (see Figure A.30)
The check valve 1 test for DCVA backflow preventers shall be conducted as follows: (a) Blow out the test cocks to remove any foreign material.
Notes: (1) Do not stand directly in front of the test cocks when turning them on or off; foreign material may be discharged or the test cocks may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

(b) To obtain proper readings from the pressure gauge, locate it at the same elevation or level as the test cock downstream of check valve 1 (test cock 3). (i) If test cock 3 is the highest point of check valve 1, the top of test cock 3 can be used as a reference point; advance to Item (c). (ii) If test cock 3 is not the highest point of check valve 1, install a vertical tube on test cock 3 so that it rises above the DCVA backflow preventer. (c) Install the bleed valve on test cock 2 as follows: (i) connect the high-pressure hose to the bleed valve; (ii) gradually open test cock 2; (iii) open the high-pressure valve; (iv) bleed the high-pressure side of the gauge; and (v) close the high-pressure valve. (d) If the tube is attached, open test cock 3 and fill the tube to an elevation that is level with the centreline of the gauge; then close test cock 3. (e) Close shut-off valve 2, then close shut-off valve 1. (f) Gradually open test cock 3; after water stops discharging from test cock 3 and the gauge stabilizes, observe the reading as follows: (i) If the reading is 6.9 kPa or greater, record the value and record that check valve 1 “closed tight”. (ii) If the gauge reading stabilizes at less than 6.9 kPa, record that check valve 1 “leaked/failed”. (g) Close all test cocks, open shut-off valve 1, and remove the gauge.

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Differential pressure gauge High-pressure valve Low-pressure valve Vertical tube
11 12 13 1 0 15 14

6 5 4 3 2

9 10

Hose Low-pressure inlet Water level to centreline of gauge

High-pressure inlet

Hose Bypass valve Test cock 2

Test cock 3 Shut-off valve 1
Test cock 1

Bleed valve Check valve 1

Check valve 2 Shut-off valve 2 Test cock 4

Figure A.30 DCVA backflow preventers — Test No. 1: Check valve 1 test
(See Clauses A.5.2.2.3 and A.5.2.2.4.)

A.5.2.2.4 Leaking shut-off valves (see Figure A.30) A.5.2.2.4.1 Leaking shut-off valve 2 (with no pressure downstream)
If the water recedes (in the vertical tube) through test cock 3, lower the centreline of the gauge to the centreline of the DCVA backflow preventer and observe and record the gauge reading as follows: (a) If the reading is 6.9 kPa or greater, record that check valve 1 “closed tight”. (b) If the reading stabilizes at less than 6.9 kPa, record that (i) check valve 1 “leaked”; (ii) shut-off valve 2 “leaked”; and (iii) check valve 2 “leaked”. (c) Advance to Item (f) of Clause A.5.2.2.3.

A.5.2.2.4.2 Leaking shut-off valves 1 and 2 (with pressure downstream)
If the water rises (in the vertical tube) through test cock 3, one of the shut-off valves could be leaking. Observe and note the gauge reading and use the following procedure: (a) Gradually open the bleed valve. (b) If water continues to flow through the bleed valve and it can be adjusted so there is only a slight rise (in the vertical tube) or a drip through test cock 3, observe and record the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record that check valve 1 “closed tight”.

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(ii) If the reading stabilizes at less than 6.9 kPa, record that check valve 1 “leaked/failed” and shut-off valve 1 “leaked”. (c) If the water flow cannot be sufficiently reduced, repair or replace shut-off valve 1 before proceeding. (d) If water does not continue to flow through the bleed valve, yet continues to flow through test cock 3, observe and record the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record that check valve 1 “closed tight”. (ii) If the reading stabilizes at less than 6.9 kPa, record that (1) check valve 1 “leaked/failed”; (2) shut-off valve 2 “leaked”; and (3) check valve 2 “leaked”. (e) Advance to Item (f) of Clause A.5.2.2.3.

A.5.2.3 DCVA backflow preventers — Test No. 2: Check valve 2 test A.5.2.3.1 Purpose
The purpose of the check valve 2 test for DCVA backflow preventers is to determine whether check valve 2 will close tight in the direction of flow and to measure the static pressure drop across check valve 2.

A.5.2.3.2 Requirements
The requirements for the check valve 1 test for DCVA backflow preventers are specified in Clause 8.3.2.

A.5.2.3.3 Procedure (see Figure A.31)
The check valve 1 test for DCVA backflow preventers shall be conducted as follows: (a) To obtain proper readings from the pressure gauge, locate it at the same elevation or level as the test cock downstream of check valve 2 (test cock 4). (i) If test cock 4 is the highest point of check valve 2, use the top of test cock 4 as a reference point; advance to Item (b). (ii) If test cock 4 is not the highest point of check valve 2, install a vertical tube on test cock 4 so that it rises above the DCVA backflow preventer. (b) Install the bleed valve on test cock 3, then (i) connect the high-pressure hose to the bleed valve; (ii) gradually open test cock 3; (iii) open the high-pressure valve; (iv) bleed the high-pressure side of the gauge; and (v) close the high-pressure valve. (c) If the vertical tube is attached, open test cock 4 and fill the tube to an elevation that is level with the centreline of the gauge; then close test cock 4. (d) With shut-off valve 2 still closed, close shut-off valve 1. (e) Gradually open test cock 4; after water stops discharging from test cock 4 and the gauge stabilizes, observe the reading as follows: (i) If the reading is 6.9 kPa or greater, record the value of the reading and that check valve 2 “closed tight”. (ii) If the gauge reading stabilizes at less than 6.9 kPa, record that check valve 2 “leaked/failed”. (f) Close all test cocks, open shut-off valve 1, and remove the gauge.

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Differential pressure gauge High-pressure valve
6 5 4 7 8 9 10 11 12 13 1 0 15 14

Low-pressure valve

Vertical tube

3 2

High-pressure inlet Bleed valve Test cock 2 Test cock 3 Bypass valve
Hoses

Lowpressure inlet

Water level to centreline of gauge

Test cock 4

Shut-off valve 1

Test cock 1

Check valve 1

Check valve 2

Shut-off valve 2

Figure A.31 DCVA backflow preventers — Test No. 2: Check valve 2 test
(See Clauses A.5.2.3.3 and A.5.2.3.4.)

A.5.2.3.4 Leaking shut-off valves (see Figure A.31) A.5.2.3.4.1 Leaking shut-off valve 2 (with no pressure downstream)
If the water recedes (in the vertical tube) or flows through test cock 4, lower the centreline of the gauge to the centreline of the DCVA backflow preventer and observe and record the gauge reading as follows: (a) If the reading is 6.9 kPa or greater, record that check valve 1 “closed tight”. (b) If the reading stabilizes at less than 6.9 kPa, record that check valve 1 “leaked/failed” and shut-off valve 2 “leaked”.

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Maintenance and field testing of backflow preventers

A.5.2.3.4.2 Leaking shut-off valves 1 and 2 (with pressure downstream)
If the water rises (in the vertical tube) or flows through test cock 4, one of the shut-off valves could be leaking. Observe and note the gauge reading, and use the following procedure: (a) Gradually open the bleed valve. (b) If water continues to flow through the bleed valve and it can be adjusted so there is only a slight rise (in the vertical tube) or a drip through test cock 4, observe and record the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record that check valve 2 “closed tight”. (ii) If the reading stabilizes at less than 6.9 kPa, record that check valve 2 “leaked/failed” and shut-off valve 1 “leaked”. (c) If water does not continue to flow through the bleed valve and yet continues to flow through test cock 4, observe and record the gauge reading as follows: (i) If the reading is 6.9 kPa or greater, record that check valve 2 “closed tight”. (ii) If the reading is less than 6.9 kPa, record that check valve 2 “leaked/failed” and shut-off valve 2 “leaked”.

A.5.2.4 DCVA backflow preventers — Test No. 3: Static line pressure test A.5.2.4.1 Purpose
The purpose of the static line pressure test for DCVA backflow preventers is to determine the static inlet pressure at the time of the test.

A.5.2.4.2 Requirements
The requirements for the static line pressure test for DCVA backflow preventers are specified in Clause 8.3.4.

A.5.2.4.3 Procedure (see Figure A.32)
The static line pressure test for DCVA backflow preventers shall be conducted as follows: (a) Connect the pressure gauge to test cock 1. (b) Open test cock 1 and bleed the gauge. (c) Observe and record the pressure reading on the test report form. (d) If the static inlet line pressure at the time of test is not recorded on the test report form, record the test as “failed”. (e) Close test cock 1 and remove the gauge.

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Pressure gauge
50

40 30 20 10 0

60 70 80 90 100

Shut-off valve 1

Test cock 2 Test cock 1 Check valve 1

Test cock 3

Test cock 4 Check valve 2

Shut-off valve 2

Figure A.32 DCVA backflow preventers — Test No. 3 — Static line pressure test
(See Clause A.5.2.4.3.)

A.5.2.5 Returning DCVA backflow preventers to service
After completing the tests specified in Clauses A.5.2.2 to A.5.2.4, DCVA backflow preventers shall be returned to service as follows: (a) Close all test cocks. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the DCVA backflow preventer for leaks. (e) Inform the regulatory authority that the water is ready to be turned on. (f) Open shut-off valve 2, putting the DCVA backflow preventer back into service.

A.6 SRPVB devices — Field testing using a 3-valve differential pressure gauge
A.6.1 Equipment required — 3-valve differential pressure gauge
Quantity 1 1 1 Description 3-valve differential pressure gauge Pressure gauge with a range of either 0 to 420 kPa, 0 to 700 kPa, or 0 to 1120 kPa, depending on the maximum line pressure Bleed valve with NPS-1/4 tee, 1/4 needle valve, 1/4 nipple, and IPS-1/4 flare adapter end

The tests specified in Clauses A.6.2 and A.6.3 shall be conducted using a 3-valve differential pressure gauge. During the tests, the gauge shall be held at the same level as the SRPVB device being tested, as illustrated in Figure A.33. To avoid damage to the gauge, it shall be gradually pressurized when using only one side of the gauge. The gauge and hoses (including hoses not used) shall be held at the same level as the SRPVB being tested.

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Maintenance and field testing of backflow preventers

A.6.2 SRPVB devices — Test No. 1: Air inlet valve test A.6.2.1 Purpose
The purpose of the air inlet valve test is to test the operation of the air inlet valve of SRPVB devices.

A.6.2.2 Requirements
The requirements for the air inlet valve test for SRPVB devices are specified in Clause 8.5.2.
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

A.6.2.3 Procedure (see Figure A.33)
The air inlet valve test for SRPVB devices shall be conducted as follows: (a) Remove the air atmospheric vent shield and conduct a physical examination of the SRPVB device to determine the condition of the air inlet valve and atmospheric vent. (b) Blow out the test cock and the bleeder to remove any foreign material.
Notes: (1) Do not stand directly in front of the test cock when turning it on or off; foreign material may be discharged or the test cock may blow off, inflicting injury. (2) It is strongly recommended that safety glasses be worn to protect the eyes.

(c) Connect the high-pressure hose to the test cock and gradually open the bleeder. (d) Bleed the gauge and hoses as follows: (i) open the high-pressure valve; (ii) open the low-pressure valve; (iii) bleed the gauge and hoses; and (iv) close the low-pressure valve. (e) Close shut-off valve 2, then close shut-off valve 1. (f) Gradually open the bleeder and relieve pressure from the SRPVB device, being careful not to drop the reading on the gauge too quickly. (g) Observe and note the gauge reading when the air inlet valve begins to open. (i) If the air inlet valve begins to open before the gauge reading drops below 6.9 kPa and is opened fully when the water is completely drained from the SRPVB device, the test shall be recorded as ‘’opened/passed’’. (ii) If the air inlet valve does not open or opens with a reading less than 6.9 kPa, the test shall be recorded as “failed to open/failed”. (h) Close the high-pressure valve, the low-pressure valve, the bleeder, and the test cock, and remove the gauge. (i) If the air inlet valve does not open, the gauge reading does not drop, and water continues to be discharged from the low-pressure valve, see Clause A.6.2.4.

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Shield High-pressure valve Differential pressure gauge Low-pressure valve Bleeder
5
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Atmospheric vent Air inlet valve

Membrane (not shown) Test cock

Hose

Shut-off valve 2 (closed position) Check valve Shut-off valve 1 (closed position)

Figure A.33 SRPVB devices — Test No. 1: Air inlet valve test
(See Clause A.6.2.3.)

A.6.2.4 Leaking shut-off valves (see Figure A.34)
If the low-pressure valve has to be opened more than one-quarter of its fully open position, it is likely that shut-off valve 1 is leaking and the following procedure shall be used: (a) To get a better seal, reopen and close shut-off valve 1. (b) If the leak persists, divert the leak so that the air inlet valve can be tested. (c) To redirect the leakage from shut-off valve 1, attach a bleed valve to the test cock and reconnect the high-pressure hose. (d) Gradually open the test cock and divert some water, monitoring the gauge until its reading stabilizes. (e) Once the leakage has been diverted through the test cock, resume testing at Item (f) of Clause A.6.2.3. (f) If the air inlet valve does not open and the leak through shut-off valve 1 exceeds the limit of test cock 1, repair or replace shut-off valve 1 before continuing the test.

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Maintenance and field testing of backflow preventers

Atmospheric vent Air inlet valve

Membrane (not shown) Test cock

Bleed valve

Shut-off valve 2 (closed position) Check valve Shut-off valve 1 (closed position)

Figure A.34 SRPVB devices — Leaking shut-off valve 1: Air inlet valve test
(See Clause A.6.2.4.)

A.6.3 SRPVB devices — Test No. 2: Check valve test A.6.3.1 Purpose
The purpose of the check valve test is to determine if the check valve of SRPVB devices will close tight in the direction of flow.

A.6.3.2 Requirements
The requirements for the check valve test for SRPVB devices are specified in Clause 8.5.3.

A.6.3.3 Procedure (see Figure A.35)
The check valve test for SRPVB devices shall be conducted as follows: (a) Open shut-off valve 1 to re-establish pressure in the SRPVB device. (b) Connect the high-pressure hose to the test cock and gradually open the test cock. (c) Bleed the gauge and hoses as follows: (i) open the high-pressure valve; (ii) open the low-pressure valve; (iii) bleed the gauge and hoses; and (iv) close the low-pressure valve. (d) Close shut-off valve 1 (shut-off valve 2 should still be closed from the air inlet valve test). (e) Open the bleeder, reducing the pressure on the downstream side of the check valve to atmospheric. When the water stops flowing from the bleeder, (i) if the gauge reading has stabilized at 6.9 kPa or greater, record that the check valve “closed tight/passed”; (ii) if the gauge reading drops to 0 kPa, or stabilizes at less than 6.9 kPa, record that the check valve “leaked/failed”; or (iii) if water continues to flow from the bleeder, see Clause A.6.3.4.

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(f) Close the test cocks and bleeder and remove the gauge. (g) Open shut-off valve 1, then open shut-off valve 2. (h) Reinstall the atmospheric vent shield.
Shield High-pressure valve
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

Differential pressure gauge

Low-pressure valve Bleeder Atmospheric vent Air inlet valve

5
HI

Membrane (not shown) Test cock

Hose

Shut-off valve 2 (closed position) Check valve Shut-off valve 1 (closed position)

Figure A.35 SRPVB devices — Test No. 2: Check valve test
(See Clause A.6.3.3.)

A.6.3.4 Leaking shut-off valves (see Figure A.36)
If water continues to flow from the bleeder (see Item (e) of Clause A.6.3.3), shut-off valve 1 is leaking and the following procedure shall be used: (a) Close the test cock and remove the hose from the gauge. (b) Attach a bleed valve to the test cock and reconnect the high-pressure hose. (c) Open the test cock (the bleeder should still be open from the check valve test). (d) Gradually open the bleed valve until the water flow from the bleeder is reduced to a slight drip. (e) Observe the reading on the gauge as the static pressure drop across the check valve decreases. (i) If the water flow ceases through the bleeder and if the gauge reading has stabilized at 6.9 kPa or greater, record that the check valve “closed tight/passed”. (ii) lf the water flow from the bleeder cannot be eliminated by opening the bleed valve, do not attempt to determine the tightness of the check valve until shut-off valve 1 is repaired or replaced.

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Maintenance and field testing of backflow preventers

Atmospheric vent Air inlet valve

Membrane (not shown) Test cock

Bleed valve

Shut-off valve 2 (closed position) Check valve Shut-off valve 1 (closed position)

Figure A.36 SRPVB devices — Leaking shut-off valve 1: Check valve test
(See Clause A.6.3.4.)

A.6.4 SRPVB devices — Test No. 3: Static line pressure A.6.4.1 Purpose
The purpose of the static line pressure test is to determine the static inlet line pressure upstream of the check valve of a SRPVB device.

A.6.4.2 Requirements
The requirements for the static line pressure test for SRPVB devices are specified in Clause 8.5.4.

A.6.4.3 Procedure (see Figure A.37)
The static line pressure test for SRPVB devices shall be conducted as follows: (a) Connect the pressure gauge to test cock 1. (b) Open test cock 1 and bleed the gauge to remove the air. (c) Observe the pressure reading and record it on the test report form. If the static inlet line pressure at the time of test is not recorded on the test report form, record the test result as “failed”. (d) Close test cock 1 and remove the gauge.

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Pressure gauge Shield
40 30 20 10
Licensed for/Autorisé à Jeff Whitaker, Utilities Kingston, Sold by/vendu par CSA on/le 4/8/2009. Single user license only. Storage, distribution or use on network prohibited./Permis d'utilisateur simple seulement. Le stockage, la distribution ou l'utilisation sur le réseau est interdit.

60 70 80 90 100

Bleeder

Atmospheric vent Air inlet valve

Membrane (not shown) Test cock

Hose

Shut-off valve 2 (closed position) Check valve

Shut-off valve 1 (closed position)

Figure A.37 SRPVB devices — Test No. 3: Static line pressure
(See Clause A.6.4.3.)

A.6.5 Returning SRPVB devices to service
After completing the tests specified in Clauses A.6.2 and A.6.3, SRPVB devices shall be returned to service as follows: (a) Close the test cock and the bleeder. (b) Remove the test equipment. (c) Ensure that shut-off valve 1 is fully open. (d) Check the SRPVB device for leaks. (e) Inform the regulatory authority that the water is ready to be turned on. (f) Open shut-off valve 2, putting the SRPVB device back into service.

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CSA-B64.10 Selection and Installation of Backflow - docshare.tips (2023)