7.6.2.4.

(1) A backflow preventer shall not be required in a residential full flow through fire sprinkler system, in which the pipe and fittings are constructed of potable water system materials.

(2) Except as required in 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 the following Clauses:

(a) Residential partial flow through fire sprinkler 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 CAN/CSA-B64.6.1, “Backflow Preventers, Dual Check Valve Type for Fire Systems (DuCF)”,

(b) Class 1 fire sprinkler/standpipe systems shall be protected by a single check valve backflow preventer conforming to CAN/CSA-B64.9, “Backflow Preventers, Single Check Valve Type for Fire Systems (SCVAF)”, provided that the systems do not use antifreeze or other additives of any kind and all pipes and fittings are constructed of potable water system materials,

(c) 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 CAN/CSA-B64.5.1, “Backflow Preventers, Double Check Valve Type for Fire Systems (DCVAF)”, provided that the systems do not use antifreeze or other additives of any kind,

(d) Class 1, Class 2 or 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 CAN/CSA-B64.4.1, “Backflow Preventers, Reduced Pressure Principle Type for Fire 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 Clauses (b) or (c),

(e) Class 4 and 5 fire sprinkler/standpipe systems shall be protected by a reduced pressure principle backflow preventer conforming to CAN/CSA-B64.4.1, “Backflow Preventers, Reduced Pressure Principle Type for Fire Systems (RPF)”,

(f) Class 6 fire sprinkler/standpipe systems shall be protected,

(i) by a double check valve backflow preventer conforming to CAN/CSA-B64.5.1, “Backflow Preventers, Double Check Valve Type for Fire Systems (DCVAF)”, or

(ii) where a potentially severe health hazard may be caused by backflow, by a reduced pressure principle backflow preventer conforming to CAN/CSA- B64.4.1, “Backflow Preventers, Reduced Pressure Principle Type for Fire Systems (RPF)”, and

(g) backflow prevention devices on fire sprinkler and standpipe systems shall be selected and installed in conformance with Table 7.6.2.4.

(3) The backflow preventer 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 the water service pipe at a service connection located on the same premises as the fire service main in Class 3, 4, 5 and 6 fire sprinkler/standpipe systems, a reduced pressure principle backflow preventer conforming to CAN/CSA-B64.4.1, “Backflow Preventers, Reduced Pressure Principle Type for Fire Systems (RPF)”, shall also be provided on the fire service connection.

(5) Except as permitted in Sentences (1) and (8), backflow preventers shall be selected, installed and tested in conformance with CAN/CSA-B64.10 “Manual for the Selection and Installation of Backflow Prevention Devices”.

(6) Backflow prevention devices shall be provided in conformance with Sentence 7.2.10.10.(1)v1.

(7) Tank type water closet valves shall be provided with a back-siphonage preventer in conformance with Sentence 7.2.10.10.(2)v1.

(8) Buildings of residential occupancy within the scope of Part 9 are not required to be isolated unless they have access to an auxiliary water supply.

(9) In addition to the backflow preventer required by this Subsection, for buildings or facilities where a potentially severe health hazard may be caused by backflow, the potable water system shall be provided with premise isolation by the installation of a reduced pressure principle backflow preventer .