Highrise PRV Floor Control Valve Testing

[bmlxd40]

Good Morning Folks,

NFPA 25, 2001 ed. section 13.5.1.2 requires that sprinkler pressure reducing valves be full flow tested every five years and the data compared to previous test results. To me, full flow testing means testing at system demand, however, the annex material in A13.5.1.2 seems to indicate that a drain valve is adequate to perform the test. Obviously, the drain valve doesn't allow you to measure the flow, so you wouldn't know if you were at "Full flow".

I am thinking a flowmeter, similar to what is used to test 2½" pressure reducing hose valves, should be connected downstream of the sprinkler PRV and connected to the 3" drain riser in a similar manner to the test for hose valves. Shouldn't the flow and residual pressure be measured to make sure the system demand is still available from the sprinkler control PRV??

 

[PEDARRIN2]

It is my understanding that sprinkler systems are tested at the flow of a single sprinkler either at the floor control valve or at a remote inspector's test. I would assume there is a pressure gauge on the upstream and downstream side of the PRV.

 

[stookeyfpe]

The main issue for sprinkler FCVs with a PRV is not a full flow test because it isn't required. The only requirement is the residual pressure doesn't exceed 165 PSIG. Essentially, you flow the test connection on the riser package. For a new building, verify the correct K factor was selected for the test orifice. This is very important, especially with some the of extended coverage sprinklers.

Now if this a standpipe with hose valves with integral PRVs, then yes, a flow meter is required to ensure the hose valve will supply the rated flow and the pressure doesn't exceed 175 PSIG.

 

[RiskConslt]

re: testing PRV's on sprinkler systems: the drain should have been sized to accommodate the full flow requirement. or use a hose into a barrel. Most important is having two pressure gauges, one up and one downstream. You could probably get away with one pressure gauge downstream if you post the actual static pressure upstream of the valve at the valve.