There is no friction loss at 0 gpm. The static at the riser will be your churn pressure plus the elevation gain.
In my opinion, you should include the mains as you describe them as part of the calculation. Todd Williams Fire Protection Design/Consulting Stonington, CT 860-608-4559 > > On May 6, 2024 at 4:57 PM, <Bob Knight (mailto:b...@firebyknight.com)> > wrote: > > > I have a project where the complete underground plan has not been provided, > yet. > What I do have is a fire pump house with a recent fire pump test. > The fire pump house is about 2,100 feet from the project site. It is > elevated about 54 feet higher as well. > I do have the underground loop around the building, so I was going to use > the connection point at the loop for the underground from the pump house as > the source point. > The pump test shows 152 psi @ 0 gpm and 101 psi @ 1500 gpm. > The elevation gain in pressure is 23.38 psi. > The friction loss through the 2,100 feet of pipe and 16 or so fittings and > valves, totals 2,372 feet. > This came out to 21.24 psi of friction loss, assuming 800 gpm of flow > including 250 gpm hose. > I'm adding the elevation gain and subtracting the friction loss from the > pump test. > This leaves me with 154.14 psi @ 0 gpm and 103.14 psi @ 1500 gpm. > I'm just going to use the numbers from the pump test and re-verify > everything at a future date. > Does this sound reasonable? > > > -- > > > > Thank you, > Bob Knight, CET III > Fire by Knight, LLC > 208-318-3057 > > > > > > > > > Virus-free.www.avg.com > (http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient) > > > > > _________________________________________________________ SprinklerForum > mailing list: > https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org > To unsubscribe send an email to sprinklerforum-le...@lists.firesprinkler.org >
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