pressure reducing valve
pressure reducing valve
(OP)
I am looking at a 6 story apt bldg that will need a fire pump to get the 100 psi residual @ top of standpipe. My customer has suggested using a 6" pressure reducing valve in the basement on the 6" main supply to the standpipes vs installing individual pressure reducing valves on each floor.
I cannot find anything that says I cannot do this, the calcs work out to allow this to happen. Are there any codes I am missing that say this cannot be done? I am looking at the 6" Tyco PRV-1.
Thanks
I cannot find anything that says I cannot do this, the calcs work out to allow this to happen. Are there any codes I am missing that say this cannot be done? I am looking at the 6" Tyco PRV-1.
Thanks





RE: pressure reducing valve
Is it possible to size your pump to churn at 175 or less and still give you the 100 psi at the hose valve outlet?
RE: pressure reducing valve
In other words what is the elevation of your highest outlet, how many standpipes are there and what is your city water supply/
RE: pressure reducing valve
13.5.4.3* A full flow test shall be conducted on each valve annually and shall be compared to previous test results.
Sorry I do not have the section in 14, but I know it is in the standard.
RE: pressure reducing valve
RE: pressure reducing valve
You will find NFPA 14 has an issue with this. It has to be arranged so that the failure of a single PRV does not effect more than 2 hose valves downstream of the PRV. I have seen this countered by putting two PRV's in parallel. This way, if one fails, the parallel one will function and act as required.
But, Stookey has a very valid point that should be investigated. Is this building a high-rise? Most 6 stories I see are mid-rise buildings. NFPA 14 permits manual standpipes in buildings other than a high rise. If you have 150 psi at the FDC inlet, you may have 20 psi of total friction loss in standpipe distribution piping. This will leave you with adequate pressure to get 69' in the air. If your valve is not higher than that, you may be OK with just using the FDC and manual standpipes.
Travis Mack
MFP Design, LLC
www.mfpdesign.com
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RE: pressure reducing valve
That might be a viable option for you maybe.