Excess pressure pumps served a purpose when risers had alarm valves with a pressure switch connected to the intermediate chamber. With adjustable flow switches on the riser piping there should never be a need for these pumps anymore.
Garth retired fitter ----- Original Message ----- From: <[email protected]> To: <[email protected]> Sent: Sunday, June 28, 2009 8:09 PM Subject: Re: mercoid switch on wet riser > Excess pressure pump. The definitive solution where someone in the range > of AHJ's takes stopping false alarms due to pressure surges. I do mean > stopping, not reducing. Required in Vancouver (and the rest of B.C.?). > Seems New Zealand is on the list. > > Can be done without the Gamewell (ADT?) unit. Not required to be listed > for fire protection service, unless unit also act as the switch for the > fire alarm system interface. > > Yours, > > Bruce Verhei > > ----- Original Message ----- > From: "Tom Duross" <[email protected]> > To: [email protected] > Sent: Sunday, June 28, 2009 7:51:04 AM GMT -08:00 US/Canada Pacific > Subject: RE: mercoid switch on wet riser > > What Todd said. They probably replaced the original compound type with a > mercury one. >>From what I know, Gamewell isn't making them anymore. I think they ceased > last summer, I drove out to get a diff. switch and they told me. > Just as an aside, my grandfather is on the patent for this and a few other > things Gamewell made before and after the depression when they were in > Newton, MA. I have a beautiful one I "kept" in my basement along with a > couple of those McCullough type switches I posted about last summer too in > really nice shape. > Of course, nothing official but my Dad has a picture of him and the crew > taken in the shop after another patent was awarded. Funny coincidence. :) > > TD > Go Red Sox! > > The old Gamewell excess pressure pumps had a very homemade look about > them. > And that sounds like what is being described. Used to be required in > Canada > and parts of Europe don't know if they still are.. > > Richard > > > Sounds like an excess pressure pump. These were used in areas with a > lot of pressure fluctuations to prevent false alarms. This was before > flow switches with delays. Gamewell was famous for these but > Firematic made a fairly simple version of the same thing. Some towns > (at least in this part of the world) required them > > > > At 11:38 AM 6/27/2009, you wrote: >>I saw something which I do not understand and hope someone can explain >>this to me. >>A 35 year old wet system, manifold with 2 alarm valves. There is a >>electric flow switch on each riser, I think added recently. >>The valves were trimmed with the normal motor gongs, etc. >>The system side gauges are piped together between the two risers, with >>check valves, a mercoid switch labeled pump switch, and another mecoid >>switch labeled alarm switch. On this piping there are 3 check valves >>and a small test cock, presumably for testing. >>There is a small pump with 1/2 in inlet from supply side of valve 2, >>which discharges into the pressure gauge piping described above. >> >>What is the purpose of this? Was it standard at one time? >> > > _______________________________________________ > Sprinklerforum mailing list > http://lists.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 > http://lists.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 http://lists.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)
