On differential dry valves, the surface area of the top of the seat is several times the water seat dimension. If a column of water of sufficient height is allowed to remain on top of this valve, the seat will never raise and allow a forward flow. I believe there is something in NFPA that specifically disallows this unless you are preparing the piping for an internal inspection.
Garth ----- Original Message ----- From: "Larrimer, Peter A" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Wednesday, March 19, 2008 3:07 PM Subject: Dry Pipe Valve going wet Forum Members: If a dry pipe valve trips and "goes wet", is there any reason why you couldn't leave the system piping filled with water assuming that the weather is not cold enough to freeze it? I am assuming that the clappers have been reset externally and that the alarm connections remain dry since they don't seem to be having problems at this time. Why would they want to use an alarm valve in place in liew of just leaving the dry pipe valve? Thanks in advance. Peter Larrimer VA _______________________________________________ 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)
