E.G like this: 5/.433=11.547 ft of head "h". From experiments: v=SQRT(2gh), so if you are getting a 5 on the pitot gage it means the water is going (2*32.2*11.547)^.5=27.27ft/sec. Now if we just knew what the reduction in the effective square feet of the 2.5 orifice was, we could start calcing something
> On May 15, 2014, at 4:01 PM, Brad Casterline <bcasterl...@fsc-inc.com> wrote: > > Hmmm.. I wonder if there is any way we can figure out how fast water would > have to be going to exert a velocity pressure of 5 psi? Could we slap > ourselves on the forehead and say Hey- the old Law of Falling Bodies works > here. ? > >> On May 15, 2014, at 11:06 AM, <rfletc...@aerofire.com> wrote: >> >> Tim, So based on 47 psi at one test valve and just a flow on the rest, what >> was the pressure on the suction flange of the pump? Can't you just plot 1500 >> gpm on flow test curve and subtract the friction and elevation losses >> between the supply and pump? >> >> Brian, Pitot the discharge for each outlet, adjust the valves to control the >> required gpm, record the total gpm, read the discharge gauge on the pump and >> subtract the pressure on the suction gauge from the pressure on the >> discharge gauge? >> I'm glad tomorrow is Friday. Ron F >> >> -----Original Message----- >> From: Tim Stone [mailto:tston...@comcast.net] >> Sent: Thursday, May 15, 2014 8:51 AM >> To: Ronl.Fletcher; Sprinklerforum@lists.firesprinkler.org >> Subject: RE: Test Header Calc >> >> Ron, >> In my case the EOR was worried about negative pressures on the suction >> flange before the sprinkler contractor ordered the pump. >> >> Regards, >> G. Tim Stone >> >> G. Tim Stone Consulting, LLC >> NICET Level III Engineering Technician >> Fire Protection Sprinkler Design >> and Consulting Services >> >> 117 Old Stage Rd. - Essex Jct., VT. 05452 >> CELL: (802) 373-0638 TEL: (802) 434-2968 Fax: (802) 434-4343 >> tston...@comcast.net >> >> -----Original Message----- >> From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] >> On Behalf Of rfletc...@aerofire.com >> Sent: Thursday, May 15, 2014 11:43 AM >> To: Sprinklerforum@lists.firesprinkler.org >> Subject: RE: Test Header Calc >> >> Okay, what am I missing? There are gauges on the suction and discharge sides >> of the pump, right? >> Ron F >> >> -----Original Message----- >> From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] >> On Behalf Of Tim Stone >> Sent: Thursday, May 15, 2014 8:36 AM >> To: Sprinklerforum@lists.firesprinkler.org >> Subject: RE: Test Header Calc >> >> Brian, >> >> I just performed this on a warehouse project with a diesel fire pump taking >> suction from a municipal water supply. The EOR wanted to know the pressures >> on the Suction Flange of the pump. >> I started off with 375 GPM on each test header valve and assigned a pressure >> of 47 PSI to one of the valves with just a flow on the rest. >> Adjust the starting pressure for your needs. >> >> Regards, >> G. Tim Stone >> >> G. Tim Stone Consulting, LLC >> NICET Level III Engineering Technician >> Fire Protection Sprinkler Design >> and Consulting Services >> >> 117 Old Stage Rd. - Essex Jct., VT. 05452 >> CELL: (802) 373-0638 TEL: (802) 434-2968 Fax: (802) 434-4343 >> tston...@comcast.net >> >> -----Original Message----- >> From: Sprinklerforum [mailto:sprinklerforum-boun...@lists.firesprinkler.org] >> On Behalf Of Brian Harris >> Sent: Thursday, May 15, 2014 11:22 AM >> To: sprinklerforum@lists.firesprinkler.org >> Subject: Test Header Calc >> >> I'm running a theoretical calc on a pump test header to try and determine if >> the existing pump is running at or near its rating, there are (4) 2-1/2" >> hose valves flowing 375 gallons each. The question I have is what pressure >> would be plugged into the calc's for each valve? I have a test chart that >> shows me a 2-1/2" orifice flowing roughly 400 gpm will have a 5 pitot >> reading. I've searched for threads on converting pitot to a residual >> pressure and it doesn't seem there is any direct correlation. I've also seen >> post that say a pitot reading and the residual are pretty close at pressure >> under 40 psi. Any help would be greatly appreciated. >> >> Brian Harris, CET >> BVS Systems Inc. >> Sprinkler Division >> bvssystemsinc.com<http://bvssystemsinc.com/> >> Phone: 704.896.9989 >> Fax: 704.896.1935 >> >> _______________________________________________ >> Sprinklerforum mailing list >> Sprinklerforum@lists.firesprinkler.org >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> >> _______________________________________________ >> Sprinklerforum mailing list >> Sprinklerforum@lists.firesprinkler.org >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> >> >> _______________________________________________ >> Sprinklerforum mailing list >> Sprinklerforum@lists.firesprinkler.org >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> >> >> >> _______________________________________________ >> Sprinklerforum mailing list >> Sprinklerforum@lists.firesprinkler.org >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list Sprinklerforum@lists.firesprinkler.org http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
