If you don't locate each separate sensing line between the discharge check and gate, then you're not reading the correct zone if the discharge valve is closed. No sense in monitoring the pressure in the discharge zone of a different pump- it could drop, and the pump whose sensing line is piped incorrectly will start, and it could pump its little impeller all day and, if its discharge valve is closed, never satisfy the pressure to shut off since its discharge isn't getting to the zone being monitored by the sensing line connected to the wrong place.
George L. Church, Jr., CET Rowe Sprinkler Systems, Inc. PO Box 407, Middleburg, PA 17842 877-324-ROWE 570-837-6335 fax [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jeff Garrison Sent: Thursday, September 22, 2011 6:57 AM To: [email protected] Subject: Re: fire pump, pressure sensing lines, tap point (now with PRedV considerations) I believe Each and Every Pump for Fire Protection service is supposed to be able to function completely independently from Each and Every other pump. This requires sensing lines that are independent from each other. On Wed, Sep 21, 2011 at 10:57 PM, å... .... <[email protected]> wrote: > Here is an old thread > that came close, but did not answer > a question I had... > > > 2010 NFPA 20 > 1 diesel, 2 electric Fire Pumps > 3 jockey pump > *** 6 pumps, 6 controllers *** > demand: deluge systems, high-rise systems, DIPA systems, > > It is understood that pump pressure sensing lines will be plumbed > between last check valve and last control valve, which are different > locations for JP versus FP. But is it OK, per NFPA, to use pressure > sensing lines that come from the same tap when used for FP-that-are- > redundant? I don't see where a violation is at. > > **to add more fuel to the fire... > there are 8, yes 8, PRedV's downstream of the FP's. > Intention there was to avoid changing original POOR design practice of > overpressurizing feed mains (the overdesigned pressure was in order > to deliver at top of standpipes in a tower. > > I expect serious jockey pump cycling, if not continuous JP operation, > because of these PRedV's. Client doesn't know what they are getting. > Apparently, neither do the designers. > Client may recognize this thread and get mad at me. I hope so. It may > take rage to elevate design to a higher stage. If that is > what it takes, then my mission is accomplished. > > Due to the authority > and respect of this forum (not a plug at any one member per se, but the > institution of this FORUM as a medium), the client may give > credibility > where previously, the designers were able to ignore well-intended-and- > successful-long-term-strategies for choices-that-are-easiest-for-they- > (the designers) to deliver. These choices, however Code complying, > surrender the client's assets to head-aches, redesign, change-orders > and delays. **** > > > -- > Scot Deal > Excelsior Fire/Al Ilham Engineering Consultants > gsm: +968 952 87345 > -------------- next part -------------- An HTML attachment was > scrubbed... > URL: < > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attac > hments/20110922/cfd69484/attachment.html > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20110922/d47e52b4/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
