That's fine for the flow, but when you add the static pressure of the
water supply with the churn pressure of the pump, you can get real
close to the 175 psi threshold. This is problem increases as
steepness of the public water supply curve increases.
At 12:01 PM 2/7/2007, you wrote:
This does not compute.
If you have a six-story building it's what, 70' high? With static
and friction head, that shouldn't be more than about 40-43 PSI from
the street, unless you're using 3" risers ...
And remember that the 100 PSI is at the discharge side of the valve;
most hose valves have at least 3 PSI and sometimes as much as 7 or 8
PSI head loss (we've had this discussion on-forum before).
Steve
-----Original Message-----
From: Todd Williams - work [mailto:[EMAIL PROTECTED]
Sent: Wednesday, February 07, 2007 6:22 AM
To: [email protected]
Subject: pump tricks
I seem to be running into several situations lately where there is a
very fine balancing act between meeting the 100 psi at the top outlet
of the standpipe and not exceeding 175 psi at the base of the riser.
(6 story hotels are a good example) Does anybody have any good ideas
they'd care to share on making these work? I'd like to limit the use
of extra-heavy pipe and fitting (especially larger sizes) and PRVs. I
have several tricks up my sleeve, but I'm running out of sleeves.
Todd
Todd G. Williams, PE
Fire Protection Design/Consulting
Stonington, Connecticut
860-535-2080
www.fpdc.com
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_______________________________________________
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http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum
Todd G. Williams, PE
Fire Protection Design/Consulting
Stonington, Connecticut
860-535-2080
www.fpdc.com
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