BCAB #1389 - Location of Shut-Off Valve for Combined Domestic/Sprinkler Water Supply, Sentence 6.1.3.(1), B.C. Plumbing Code
April 20, 1995
Re: Location of Shut-Off Valve for Combined Domestic/Sprinkler Water Supply, Sentence 6.1.3.(1), B.C. Plumbing Code
The project in question is a mixed use commercial/residential building with a parking garage. The building is sprinklered using systems designed to NFPA 13 and NFPA 13R. Both the sprinkler systems and the domestic water system are supplied by the same 4 inch water supply pipe which enters the building through a water entry room in the parking garage.
As presently installed the combined 4 inch water service enters the building vertically through the concrete slab on ground then splits at a 4" x 2" x 3" tee into a 3" sprinkler supply and a 2" domestic supply. The sprinkler system and domestic system have shut-off valves after the tee.
Reason for Appeal
Sentence 6.1.3.(1) of the B.C. Plumbing Code requires the incoming water service to be provided with a shut-off valve "where the pipe enters the building". Sentence 18.104.22.168.(5) of the B.C. Building Code requires control valves to be provided "so that either system can be shut off independently" where a water supply serves both a sprinkler system and other equipment.
The appellant contends that the installation meets the requirements of the Plumbing Code and the Building Code as well as Figure B-2.3.1 in Appendix B of NFPA 13. The appellant notes that the term "point of pipe entry" as used by the building official does not appear in the Plumbing Code and considers the shut-off valve for the domestic water system, located 18" beyond the tee which is 24" above the floor, is within the intent of the words "where the pipe enters the building" in Sentence 6.1.3.(1).
The appellant objects to the installation of an additional shut-off valve on the inlet side of the tee because this would increase the likelihood of the fire protection systems being rendered inoperable by the inadvertent closure of a valve at the "point of entry" in the event or repairs to the domestic plumbing system. The appellant also counters the building officials contention that the main supply valve arrangement must comply with the requirements of NFPA 13R which shows main shut-off valves in advance of the tee. The water supply enters the building in the parking garage where an NFPA 13 system is used and NFPA 13 should govern the installation of the combined service.
Building Official's Position
The building official maintains that for the system to comply with Sentence 6.1.3.(1) of the Plumbing Code a shut-off valve is required before the 4" pipe enters the 4" x 3" x 2" tee. This provides an essential safety factor for the sprinkler system because if the main shut-off valve is closed the domestic system is turned off which cannot be ignored by the building's occupants. Having the main shut-off valve prior to the tee also complies with the requirements of NFPA 13R and renders it unnecessary to use the backflow prevention valve as the shut-off for the sprinklers. The building official has been advised that the valve forming part of this assembly is for test purposes only and is not intended as the main fire line shut-off.
Appeal Board Decision #1389
It is the determination of the Board that Sentence 6.1.3.(1) of the Plumbing Code requires a (single) shut-off valve as close as practical to where the water service pipe enters the building and before it branches into the water distribution system. In the case under appeal the Board considers a shut-off valve should be installed between the floor slab and the 4" x 3" x 2" tee. In addition, Sentence 22.214.171.124.(5) or Article 126.96.36.199. of the Building Code require the sprinkler system and the domestic system to be capable of being shut off independently which requires additional shut-off valves for each system. Such an installation does not contravene the requirements of NFPA 13.
George R. Humphrey, Chair