Thom: 13D does not require a waterflow switch for standalone or multipurpose however, it is often required by the local AHJ.
A waterflow switch according to UL Standards must operate not before 4 GPM and not after 10 GPM. Most of the time on a small pipe WFD the trip point is between 8 & 9 GPM. In addition there is a retarding device that would need to be overcome to trip the switch and that can be as long a 70-90 seconds. One manufacture has a special listed device that operates at 12 GPM. Most plumbing fixtures do not approach that kind of flow. A toilet is 1.6 GPM a standard shower is 3 GPM. so even with several fixtures operating at one time the switch won't trip. The hot water demand is taken off before the WFD and if there is a large demand fixture like a big pan head shower or tub the large demand these fixtures come off the manifold before the WFD. The passive purge type system is the most common system we see which will have one to three water closets connected to the sprinkler piping. This is a good way to know that you have an active open water supply. The elimination of the backflow device is one of the key features of a multipurpose system. . . . saves the initial expense and the annual testing. Mike Cabral ---- Thom McMahon <[email protected]> wrote: > Mike: > > Just a question or two, how would you have a flow sw. on a multipurpose or > passive purge system? Wouldn't it go off every time the toilet flushed or > whatever fixture purged it flowed water? > I thought the beauty of the multipurpose systems was that if the plumbing > worked the system was working, so no inspection needed, cause the only way > to turn one off was to turn off the plumbing? > > Thom McMahon, SET > Firetech, Inc. > 2560 Copper Ridge Dr > P.O. Box 882136 > Steamboat Springs, CO 80488 > Tel: 970-879-7952 > Fax: 970-879-7926 > > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Mike Cabral > Sent: Wednesday, March 03, 2010 1:17 PM > To: [email protected] > Subject: 13D Multipurpose Inspection > > I am looking for a contractor in the Coeur d'Alene, ID area to do a State > required inspection on a 13D multipurpose system( 4) four group homes. 13D > exempts' NFPA 25 inspections however, the State wants a walk through to > check valve positions etc. and ring the waterflow switch. The system is a > Rehau PEX installation I am not sure if it's fully integrated or a passive > purge/flow through installation. > > Anyone interested in the area please contact me off forum and I will provide > contact information. > > Thanks, > > [email protected] > > > Michael Cabral > Account Manager > BUILDING TECHNOLOGY-FIRE PROTECTION > REHAU Construction LLC > CELL 314-412-1800 > > Mike Cabral > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
