We are not concerned about friction loss in the manual standpipe unless there is over 200 ft. or so of 4 in., or smaller, pipe to any hose connections, and then we would ask for calculations. But at that point in the discussion the designer typically just reduces the amount of 4 in. pipe in lieu of calculations. For high rises our code requires all 6 in. pipe.
The engines used here can pump in excess of 350 psi at large volumes, so the only limiting factor in the discussion for us is the 175 psi limit. This may be different in other areras, I don't know. Wait, there is no 175 psi limit in NFPA 14. I suppose one could theoretically calculate a standpipe with high pressure pipe, fittings, and FDC, using PRV's at all hose connections and have real small pipe for their standpipe and meet NFPA 14. It would be a terrible design, IMHO, but meet NFPA 14 ( I think?). Fortunately, I have never been asked to approve such a design, and really there is only a handful of times where we asked a designer to increase some of the 4 in. pipe to 6 in., and those were fairly large buildings. Rich Richardson Seattle Fire Department >>> Roland Huggins <[EMAIL PROTECTED]> 08/07/07 7:58 AM >>> Rich - do you really NOT require calculations on a manual even when it is NOT a pipe schedule system? Roland On Aug 6, 2007, at 1:37 PM, R Richardson wrote: > > 2) Unless you were to use lots of 4 in. pipe (in lieu of 6 in.) we > would not require calculations at all for a manual standpipe, we > don't require the standpipe flow test at acceptance either, some > would call these policies risky. _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
