7.6.2.4.Backflow from Fire Protection Systems

(1) A backflow preventer shall not be required in residential full flow-through fire sprinkler/standpipe systems in which the pipes and fittings are constructed of potable water system materials. (2) Except as required by Sentence (4), potable water system connections to fire sprinkler and standpipe systems shall be protected against backflow caused by back-siphonage or back pressure in conformance with Clauses (a) to (g), as applicable: (a) residential partial flow-through fire sprinkler/standpipe systems in which the pipes and fittings are constructed of potable water system materials shall be protected by a dual check valve backflow preventer conforming to (i) CSA B64.6, “Dual check valve (DuC) backflow preventers,” or (ii) CSA B64.6.1, “Dual check valve backflow preventers for fire protection systems (DuCF),” (b) provided that the systems do not use antifreeze or other additives of any kind and that all pipes and fittings are constructed of potable water system materials, Class 1 fire sprinkler/standpipe systems shall be protected by a single or dual check valve backflow preventer conforming to (i) CSA B64.6, “Dual check valve (DuC) backflow preventers,” or (ii) CSA B64.9, “Single check valve backflow preventers for fire protection systems (SCVAF),” (c) provided that the systems do not use antifreeze or other additives of any kind, Class 1 fire sprinkler/standpipe systems not covered by Clause (b) as well as Class 2 and Class 3 fire sprinkler/standpipe systems shall be protected by a double check valve backflow preventer conforming to (i) CSA B64.5, “Double check valve (DCVA) backflow preventers,” or (ii) CSA B64.5.1, “Double check valve backflow preventers for fire protection systems (DCVAF),” (d) Class 1, Class 2 or Class 3 Class 3 fire sprinkler/standpipe systems in which antifreeze or other additives are used shall be protected by a reduced pressure principle backflow preventer conforming to (i) CSA B64.4, “Reduced pressure principle (RP) backflow preventers,” or (ii) CSA B64.4.1, “Reduced pressure principle backflow preventers for fire protection systems (RPF),” installed on the portion of the system that uses the additives and the balance of the system shall be protected as required by Clause (b) or (c), (e) Class 4 and Class 5 fire sprinkler/standpipe systems shall be protected by a reduced pressure principle backflow preventer conforming to (i) CSA B64.4, “Reduced pressure principle (RP) backflow preventers,” or (ii) CSA B64.4.1, “Reduced pressure principle backflow preventers for fire protection systems (RPF),” (f) Class 6 fire sprinkler/standpipe systems shall be protected by a double check valve backflow preventer conforming to (i) CSA B64.5, “Double check valve (DCVA) backflow preventers,” or (ii) CSA B64.5.1, “Double check valve backflow preventers for fire protection systems (DCVAF).” (g) where a potentially severe health hazard may be caused by backflow, Class 6 fire sprinkler/standpipe systems shall be protected by a reduced pressure principle backflow preventer conforming to (i) CSA B64.4, “Reduced pressure principle (RP) backflow preventers,” or (ii) CSA B64.4.1, “Reduced pressure principle backflow preventers for fire protection systems (RPF).” (3) Backflow preventers required by Sentence (2) shall be installed upstream of the fire department pumper connection. (4) Where a reduced pressure principle backflow preventer is required on a water service pipe at a fire service connection located on the same premises as the fire service pipe in Class 3, 4, 5 and 6 fire sprinkler/standpipe systems, a reduced pressure principle backflow preventer conforming to CSA B64.4.1, “Reduced pressure principle backflow preventers for fire protection systems (RPF),” shall also be required on the fire service connection.