If it's an angle valve, 2 1/2" IPSF by 2 1/2" NSHF, it's probably a globe
pattern.
Powhatton is gone, he shut down rather than cave into union demands.
Giacommini's angle globe will show about 10-15 PSI at 250 and maybe twice
that at 500.
I'm sorry to say but they're about the only decent one left, imho.
There are some mexican and chinese valves that have a lot more loss than the
giacco.
I'm not waving a flag or bashing manufacturers but they're not all the same.
Giacco btw is cast in China but assembled in Italy, as opposed to their
"Italy" mark.
I'm happy to share standpipe testing results with you, I have lots.
I don't, as practice, show incoming residuals when testing non-pr hose
valves but I do take the data.
We're not required to and I don't want to confuse things.
I'm not absolutely certain about converting to equivalent feet but I know
the pressure losses.
I know what they publish and claim, but they're like backflows, off some.
:)
One example, a single 4" 4 story mixed use I did at 0500 this morning with
BFD with a pumper truck:
62 PSI (S) - 60 (R) on the draft hydrant.
60 PSI (S) - 60 (R) on the suction gauge of the piece.
150 PSI (S) - 200 (R) on the discharge gauge of the piece.
145 PSI (S) - 155 (R) on the FDC.
125 PSI (S) - 130 (R) on the top of the Standpipe.
125 PSI (S) - 100 (R) on the outlet of the FDV @ 505 GPM.
1250 Hale (decommissioned piece), 4" x 10' LDH in and 2) 2.5" x 50' out.
The FDV was a B-K, chinese made I believe right off the 4" LW standpipe with
a 4x2.5 MT and 2.5x4 nipple.
Pretty straight shot from where the FDC ties in after the backflow, 20'
offset and straight up.
If I sized a pump for this, it would fail, slightly, but it would fail.
Unless you're dancing close to the 175 PSI threshold, be conservative.
One note, we technically failed because it was supposed to deliver 100 with
150 in and we needed 155.
They cut the sprinkler contractor some slack because it was close.
I know it would have been better with a giacco.
Why do we allow pressure restricting and pressure reducing valves to be
installed?
Why isn't it straight non-regulating and/or pressure regulating only?
Tom Duross
Go Red Sox
(Yankee's don't suck but I hope they loose big.)
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
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