I'm looking for data on the flow characteristics through FD standpipe hose
valves. NFPA 13 and 14 has 31' for an angle valve and 70' for a globe
valve. At least 2 manufactures today said the data doesn't exist.
So how does one properly calculate a standpipe correctly? Basically, I'm
questioning the NFPA 13 and 14 values to see if they are accurate. I would
like to find they are a bit high considering 9.4 psi loss for an angle
valve, short nipple and tee at 250 gpm. My concern is they are low and
there is much more loss through them.
Tom Duross I believe has mentioned many times experiences of problems when
conducting actual field testing. I believe he attributed some of the
problems to the valve. Was that because they weren't considered at all or
were considered but not correctly or were considered correctly and the
values in 13 and 14 are wrong?
We are working on an existing 2 story with a pump where they are adding 3
more stories. The pump isn't even capable of supplying a 2 story building
standpipe never mind the added demands of a 5 story. This is fine as we are
heading to a wet-manual standpipe anyway. The existing risers are 4"
instead of the original 6" specified. So 500 gpm through the existing 4"
burns up some pressure. It works but barely and only if the angle valve
losses are correct.
Chris Cahill, P.E.
Fire Protection Engineer
Sentry Fire Protection, Inc.
763-658-4483
763-658-4921 fax
Email: [EMAIL PROTECTED]
Mail: P.O. Box 69
Waverly, MN 55390
Location: 4439 Hwy 12 SW
Waverly, MN 55390
_______________________________________________
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)
