We have a proposed fire hydrant in our county that will have pressures ranging from 210 psi to 250 psi according to the engineer designing the underground line.
My Chief and I are looking into this in regards to NFPA standards/applicable code, and are concerned that the high pressure could injure firefighters or damage equipment. Is there a maximum permitted pressure that a hydrant can be, per code? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
9 Comments
Alex
8/1/2022 06:54:37 am
Hi,
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chad
8/1/2022 08:12:57 am
I concur with Alex.
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Glenn Berger
8/1/2022 08:11:01 am
Delivered pressure of 210 to 250 psi is way to high. Need to ensure that the hydrants provided can support that pressure and that the Fire Department approves.
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Greg
8/1/2022 08:35:14 am
I'm in agreement with Glenn that the pressure is too high. My experience with similar pressures as noted by Glenn was in a transmission type pipe in Nevada. The water's source was elevated in a nearby mountain range and the main transmission piping network had very very high pressures. The water sent to the fire hydrant networks required pressure reduction.
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Aaron
8/1/2022 09:14:01 am
As an engineer who has decades of municipal and private experience with transmission, distribution and point of use I can say that something sounds quite off here.
Fred walker
8/1/2022 10:13:59 am
There are some cities like Baltimore and San Francisco (there are others) which operate high pressure / high volume fire protection water distribution systems separate from the potable distribution systems. Some of these are capable of pressures you have indicated.
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Jesse
8/1/2022 01:45:35 pm
I concur with Alex. This is too high
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Dwight
8/1/2022 07:02:59 pm
Ever been on the business end of a manual hose line with 175 psi on it? It is not fun, and totally unproductive. In fact, it is on the borderline of dangerous. For fixed appliances it can work, but not for a mixture of the two (manual and fixed). For manual firefighting the nozzle pressures typically vary between 50 psi for straight bore and 100 psi for fog tips. Even at a supply pressure of150 psi, your discharge pressure from the engine will be about 175 psi, at idle.
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Jay
8/2/2022 10:45:41 am
Our fire engines have intake relief valves set at 145psi, so that's something you'll want to look into cause you'll be dumping water like crazy. Also think about the LDH you'll be using to connect the hydrant to the pumper.....what is its maximum working pressure?
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