Very good point..
Anthony Carrizosa
Project Manager | Fire Protection
7855 S 206th St Kent, WA 98032
Cell: 206-679-5283 | Office Dir: 253-341-4593
[cid:image001.jpg@01D9EFB2.8A0830B0]
What a great discussion this has been! I see it as my job to present a
design to my customer, the AHJ, and the specifying engineer (and
potentially other stakeholders) a design that attempts to address their
respective concerns as we attempt to work together to provide a system that
offers a
Let’s look at it another way: I have a two-riser standpipe system with 750 gpm
demand; my water supply duration is 30 minutes, so I need to store 22,500
gallons. If I have a break tank that’s got water in it up to a point that
floods pump suction (let’s say the water column is 6” over the
I don't believe it states whether the spacing is along branches or between
Max spacing is 12'-0 but max coverage is still only 100sqft
Thanks
Brett Peters
General Manager Installation & Design
Proudline Fire Protection Services Ltd.
br...@proudline.ca
780 490 7602 office ext 202
780 490 7605
Steve, I understand your point but the IBC says Secondary water supply. Thus a
second water supply as a backup to the main or primary supply. 403.3.3
describes : An additional fire
pump shall not be required for the secondary water supply
unless needed to provide the minimum design intake
Is the spacing of 12' in building less than 30' in table 14.2.8.2.1 of the 2019
NFPA 13 along the branchline or can it be between the branchlines? I feel it's
along the branchline but can't find my confirmation.
Joe
Burtell | SET, CFPS
Fire Sprinkler Manager
D
C
406-204-4653
406-861-4507
3004
We have designed and overseen construction of numerous PIP concrete tanks built
into the parkade basements of high-rise buildings. We generally line them
with a product that’s mostly polyurethane in composition, formulated to bond
especially well with concrete.Inspection doesn’t require a
I think you’re blurring 403.3.2 and 403.3.3. If you need two separate city
connections based on building height, you can still fill a break tank with
supply lines connected to separate main legs as prescribed. 403.3.3 doesn’t
say anything about the connection configuration of pump to tank
Per NFPA 25 Tank internal inspection is required every five years.
From: Travis Mack
Sent: Monday, September 25, 2023 12:22 PM
To: Discussion list on issues relating to automatic fire sprinklers
Subject: [Sprinklerforum] Re: Standpipe PRV Question
That makes total sense and I can see where
That makes total sense and I can see where some projects I did in your area in
the past were specified that way. I thought it odd, but I see the reasoning
behind it now.
Travis Mack, SET
M.E.P.CAD | Instructor / Support
181 N. Arroyo Grande Blvd. #105 I Henderson, NV 89074
True, if your tank is down for maintenance…
That occurs pretty infrequently, I’m sure we all agree. Like maybe once every
20 years or so? We take sprinkler systems in and out of service without any
special consideration all the time and keep in mind that there are options for
fire watch,
Steve, I understand the argument but I think that eliminates having two
supplies to the fire pump, if you are only filling the tank and using the
tank as the sole supply to the fire pump then you only have on supply, what
happens if in the case of some type of event you actually lose the tank but
Steve:
I was envisioning that you had your city supply going to the tank and you had
the full tank. So if there is activation, you have either city supply or tank
as back up. That is no issue. But if there is no direct bypass around the
tank, then when your tank is down for maintenance,
Respectfully don’t concur.
The point of the tank is to store a reserve of standpipe water or sprinkler
water, whichever volume is highest given demand x duration. This requirement
is intended to mitigate interruption of the primary water supply (city main)
due to a cataclysmic seismic event
Micah,
To add to what Anthony just posted, I think the key point that may have been
missed in your initial question is that the secondary water supply needs to be
“automatic” all on its own. This means that is needs to be equivalent to the
city water supply in available gpm and pressure before
We utilized a secondary pump with tank supply, as Mr. Carrizuosa explains
below, on a project recently.
Our challenge was the tank had to be located underground because there was not
enough room in the basement and we had to be very carefull with our vortex
plate elevation to avoid exceeding
In my opinion, that is not dual water supplies. If the tank is down your water
supply is down. You need one connected to the city and one connected to the
tank. Yes. It can be quite tough to balance that calc. I’ve had to put a PRV on
the incoming line so as to basically kill most of the supply
Micah,
We typically design ours with a primary pump taking suction from the city main
and a secondary pump taking suction from the tank.
The primary is of course designed to provide the required pressure to meet the
standpipe design. The secondary pump is sized to provide an equivalent pressure
Thank you for the response, Steve! Does the redundant fill valves for the
tank satisfy the secondary supply requirement of the IBC without an
additional tank? I was interpreting the city main connected to the pump as
the primary supply and the tank as the secondary supply (or vice versa).
If my
Micah:
The best way to stabilize the pump discharge pressure and give yourself a
(nearly) straight line suction pressure curve is to arrange the required
secondary water supply as a break tank. Fill the tank with city water
(recommend to manifold at least one automatic plus one manual fill;
Good morning, Forum!
I've got a head-scratcher and am interested in the Forum's collective
opinion! Important project parameters are as follows.
- 42-story high rise with an automatic standpipe
- Seismic Design Category - C
- IBC 2018
- Fire pump supplied by city water supply
- Secondary
21 matches
Mail list logo
