Would the 7 psi minimum operating pressure from NFPA 13 Calculation
Procedure apply to open head deluge, since the operating parts have already
been ejected clear of the frame and deflector by a ball-peen hammer?
Brad Casterline, NICET IV
Fire Protection Division
FSC, Inc.
P:
Doesn't the 7 psi also have to do with minimum pressures to develop spray
patterns properly? If so, you would still need the 7 psi minimum.
Travis Mack, SET
MFP Design, LLC
Sent from my iPhone
On May 21, 2013, at 6:03 AM, Brad Casterline bcasterl...@fsc-inc.com wrote:
Would the 7 psi
makes sense, thanks Travis
-Original Message-
From: Travis Mack [mailto:tm...@mfpdesign.com]
Sent: Tuesday, May 21, 2013 8:06 AM
To: sprinklerforum@lists.firesprinkler.org
Subject: Re: calc procedure logic
Doesn't the 7 psi also have to do with minimum pressures to develop spray
Wouldn't it depend on the application rate, area of protection and orifice size?
Mark at Aero
- Original Message -
From: Brad Casterline [mailto:bcasterl...@fsc-inc.com]
Sent: Tuesday, May 21, 2013 01:03 PM
To: sprinklerforum@lists.firesprinkler.org
sprinklerforum@lists.firesprinkler.org
The 7.0 PSI end head minimum pressure was never intended to kick out the
links, seat etc, but to develop the minimum spray pattern required to
deliver the specified density.
John O'Connor
National Fire Sprinklers, Inc.
Nashville TN
-Original Message-
From:
For example foam/water deluge .16/entire area, heads 9x9=81, times .16=12.96
gpm/head, throwing 4'-6 each way. The requirement to balance the flows
within 15% of each other is physical (we want a fairly uniform blanket on
the floor), but the 7 psi min is not physical, unless 5.48 psi will not
My recollection of the 7 psi min ehp was to make sure the cap was removed and
an acceptable pattern developed.
Thought it took 5 psi to clear the waterway so 7 became the min, maybe for
pattern, maybe buffer.
Mark, that's a Min ehp. With today's hi perf heads we often need lots more,
Thanks John. Assuming that is true, we could say a 1/2 head at 7 psi throws
7'-6 each way. At 7 psi the water hits the deflector going 32.26 ft/sec.
v=SQRT(2gh). At 6 psi it would be going 29.87 ft/sec, and would throw 6'-11
each way.
-Original Message-
From: John O'Connor
Except that you are designing outside the standard.
Can't recall ever even thinking of approaching an AHJ with 6 psi instead of 7.
Sent from my iPhone
On May 21, 2013, at 9:58 AM, Brad Casterline bcasterl...@fsc-inc.com wrote:
Thanks John. Assuming that is true, we could say a 1/2 head at 7
My understanding of sprinkler design is that the cap is supposed to be ejected
away from the sprinkler regardless of the pressure available. As soon as the
element fuses, the cap springs free and clear - it should work whether its
attached to a live system or sitting on your desk as a display.
During Phoenix summers we verify that every time a box of heads sits outside in
the back of a truck.
Ron F
-Original Message-
From: sprinklerforum-boun...@lists.firesprinkler.org
[mailto:sprinklerforum-boun...@lists.firesprinkler.org] On Behalf Of Mark A.
Sornsin, P.E.
Sent: Tuesday,
lol Ron!
Mark, I think there are 2 schools of thought about this, but in the case of
open head deluge it should not matter. The question then is one of the
pattern, and it is not like the pattern drops from 7'-6 radius to 0 at less
than 7 psi! This could have a huge effect on the cost of big
At this point the common NICET level design has been left behind. I'd expect a
rational analysis with a P.E. stamp. This is no longer an NFPA 13 system, at
least for this aspect.
Third party review by another P.E.? I don't know. I'd have to consider it
further.
bv
- Original Message
In days of yore we would use 4.2K's mixed with 5.6K's for balancing. The low K
higher pressure makes it much easier to balance and with 4.2's there was no
danger of going below 7 psi. Now only 5.6 8k are listed with AFFF.
Ron F
-Original Message-
From:
I have building where we are getting ready to commission the standpipes.
The most remote standpipe I have access to the roof and can utilize my
hose monster in order to achieve my flow rates. My second standpipe has
no access to the roof. I know hydroflow makes an inline pitotless nozzle
for an
You are confusing velocity with vector. Same head at 50 psi doesn't go much
farther.
Go grab a head and take a match to it. The link surely clears. The cap if
upright stays. If pendant gravity takes care of it. Then you can see how
little it takes to clear the cap.
Why 7 psi? Why
Are you testing the water supply and gpm/psi? If you flow 500 gpm at the
remote you can flow 250 or 500 through any outlet even on the 1st floor.
IMHO
Arthur Tiroly
ATCO Fire Protection Design
Tiroly and Associates
24400 Highland Rd rm 25, CLE 44143
216-621-8899
216-570-7030 Cell
Don't you still have to show that you have 100psi at the top most outlet
at the other flowing standpipes?
Thanks,
Dewayne
-Original Message-
From: sprinklerforum-boun...@lists.firesprinkler.org
[mailto:sprinklerforum-boun...@lists.firesprinkler.org] On Behalf Of Art
Tiroly
Sent: Tuesday,
Add some dried sludge and age 20 years.
Mark, did u see the clogged drops on a DIPreAction sys up your way? I realize
we need to maintain and cure bad ones with testing, but reality testing should
include aging and normal degradation of system.
Sent from my iPhone
On May 21, 2013, at 4:28
The 2nd SP is closer to the supply and you are only flowing 250 then the
pressure will be at least as high as the most remote or slightly higher. You
need to account for all the gpm and pressure reading at the most remote.
Arthur Tiroly
ATCO Fire Protection Design
Tiroly and Associates
24400
7 psi is equivalent to ~32 ft/sec, another why. 400 heads at 130 s.f.
=52,000 s.f. the standard ceiling jet is ~12 deep under smooth ceiling...
I told my boss a while back there is nothing arbitrary in 13, then
craw-fished out of the statement with, I have not found anything yet that
was not based
It doesn't matter what kind of math you do. You can't cipher your way out
of this one. Sixth grade graduate and all not withstanding. The book says 7
psi. The baseline protocols for all standard spray heads are predicated on
7 psi. Want something else then develop a head. Convince UL that a new
All flows have to be from the tops.
Get a flowmeter and hose it to the street.
I do it all the time.
-Original Message-
From: sprinklerforum-boun...@lists.firesprinkler.org
[mailto:sprinklerforum-boun...@lists.firesprinkler.org] On Behalf Of Art
Tiroly
Sent: Tuesday, May 21, 2013 5:07 PM
Chris forgot to ask where babies come from. The answer - as I understand it -
to the 52,000 sq. ft. question is ... mildly amusing.
SL
-Original Message-
From: sprinklerforum-boun...@lists.firesprinkler.org on behalf of George Church
Sent: Tue 5/21/2013 1:58 PM
To:
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