The Ontario Building Code | Backflow from Fire Protection Systems

7.6.2.4. backflow from Fire Protection Systems

(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), potablewater system connections to fire sprinkler and standpipe systems shall be protected against backflowcaused by back-siphonage or back pressure in conformance with the following Clauses:

(a) residentialpartial 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 CSA B64.6.1, "Dual Check Valve backflow Preventers for Fire Protection Systems (DuCF)",

(b) Class 1 fire sprinkler/standpipe systems shall be protected by a single check valve backflow preventer conforming to CSA B64.9, "Single Check Valve backflow Preventers for Fire Protection 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 CSA B64.5.1, "Double Check Valve backflow Preventers for Fire Protection 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 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 4and Class 5 fire sprinkler/standpipe systems shall be protected by a reduced pressure principle backflow preventer conforming to CSA B64.4.1, "Reduced pressure Principle backflow Preventers for Fire Protection Systems (RPF)",

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

(i) by a double check valve backflow preventer conforming to CSA B64.5.1, "Double Check Valve backflow Preventers for Fire Protection Systems (DCVAF)", or

(ii) where a severe hazard may be caused by backflow, by a reduced pressure principle backflow preventer conforming to CSA B64.4.1, "Reduced pressure Principle backflow Preventers for Fire Protection Systems (RPF)", and

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

Table 7.6.2.4.
backflow Preventers on Fire Sprinkler and Standpipe Systems

Forming Part of Sentence 7.6.2.4.(2)

Item	Column 1	Column 2	Column 3	Column 4	Column 5	Column 6
	CSA Standard Number	Type of Device(1)	System Made with Potable water System Materials		System Not Made with Potable water System Materials
			Minor Hazard(2) residential Partial Flow-Through System	Minor Hazard(2) Class 1 System	Moderate Hazard(2) Class 1, 2, 3 and 6 Systems	Severe Hazard(2) – Any Class of System in which Antifreeze or Other Additives Are Used
1.	B64.6.1	DuCF	P	NP	NP	NP
2.	B64.9	SCVAF	P	P	NP	NP
3.	B64.5.1	DCVAF	P	P	P	NP
4.	B64.4.1	RPF	P	P	P	P

Notes to Table 7.6.2.4.:

P – Permitted

NP – Not Permitted

⁽¹⁾ The product is only permitted for use on fire sprinkler and standpipe systems.

⁽²⁾ Minor Hazard, Moderate Hazard and Severe Hazard have the same meaning as indicated in CSA B64.10 "Selection and installation of Backflow Preventers".

(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 CSA B64.4.1, "Reduced pressure Principle backflow Preventers for Fire Protection Systems (RPF)", shall also be provided on the fire service connection.