How about a more basic question. Why do you even have a relief valve? With a rating of only 105 psi exceeding 175 psi with a tank feed requires a tall tank.
Roland On Mar 19, 2009, at 11:23 PM, A.P.Silva wrote: > > The building owner wants to connect the discharge piping from the pump > relief valve to the pump suction pipe, just upstream of the suction > valve. > The water supply to the pump is a water storage tank. Anyone seen this > arrangement? Is it acceptable? > > NFPA 20, 2007 section 5.18.7 mentions "Discharge to Source of > Supply". Is > this to the tank or can it be also to the suction pipe? Both 5.18.7 > and > A5.18.7, seems to have a concern regarding the size of the relief > valve and > discharge piping, but does not provide much guidance (in my > opinion). Anyone > care to expand on this concern? > > The fire pump is rated 1000 gpm @ 105 psi. The source as mentioned > previously, are gravity tanks. The relief valve is 4" and discharge > pipe is > 8" corresponding to Table 5.25. The discharge piping from the relief > valve > to connection at pump suction pipe has one elbow. At the connection > to the > pump suction there is a tee. Is the tee to be counted and the sizing > be > increased as per 5.18.6.2 ? > > Any pump experts? > > Tony > > _______________________________________________ > 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)
