PRV before Reduced pressure backflow?

[FireFreak08]

Is there any reason that you cannot put a pressure reducing valve before a reduced pressure backflow on an incoming fire service? I can't seem to find anything that says you can't.

 

[stookeyfpe]

It's a fairly common practice in certain areas of my community that have some pretty significant grade changes. In my case, the water utility installs them.

 

[FireFreak08]

Thanks. This is in regards to a previous post I made. Either a relief valve or reducing valve is the only thing I can think of. Evidently there are some high pressure surges in the city system.

http://www.eng-tips.com/viewthread.cfm?qid=361483

 

[LCREP]

Make sure you install a test header after the PRV so it can be flow tested annually as per NFPA 25 2014, see below. Also required to forward flow the RPZ test header required as per NFPA 13.


13.5.4 Master Pressure-Regulating Devices.
13.5.4.1* Devices shall be inspected weekly to verify that the
devices are in the following condition:
(1)*The downstream pressures are maintained in accordance with the design criteria.
(2) The supply pressure is in accordance with the design cri- teria.
(3) The devices are not leaking.
(4) The devices and trim are in good condition.
13.5.4.2* A partial flow test adequate to move the valve from its seat shall be conducted quarterly.
13.5.4.3* A full flow test shall be conducted on each valve annually and shall be compared to previous test results.
13.5.4.4 When valve adjustments are necessary, they shall be made in accordance with the manufacturer’s instructions.

 

[LCREP]

FYI

Link