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Thanks but not what I was looking for....what I meant is the max flow a hose will flow....regardless of nozzle. Regardless of pressure there is a max flow that hose can attain.
Larry,
This goes back to the late 70's when I was a pump operator. We refered what you are asking as the "redline" GPM flow for the size lines we were using. The Illinios Fire Service Institute Pump Operators course was the bases for this info. You might be able to get more current info there.
Basically the redline rule of thumb was:
1 1/2 - 100 gpm
1 3/4 - 150 gpm (?)
2 1/2 - 400 gpm
3 - 600 gpm
At least this is the best my memory can come up with short of going through some of my old pump operators stuff, lots of dust involved.
Tom
Scott Wetmore said:Thanks but not what I was looking for....what I meant is the max flow a hose will flow....regardless of nozzle. Regardless of pressure there is a max flow that hose can attain.
I think you're missing something here Larry. NFPA 1901 says all 2.5" discharges must flow at least 250 gpm at 150 psi, but do not limit the flow. You can have your pumper piped any way you like as long as you hit the minimums. Point being, you can flow 250 gpm through a 1.5" line off the right discharge. The theoretical friction loss alone would be 150 psi then add your nozzle pressure in, but any class A fire pump will be able to supply the line. Not a good set up, but easily attainable. Heck we just flowed 350 gpm through an 1.75" line using a Vindicator nozzle.1st. NFPA 1901 requires that all 2 1/2 inch fittings on pumping apparatus flow 250 gpm at 150 psig. So you will not be putting 250 gpm through an inch and a half line reguardless of the pressure.
Larry Lasich said:I think you're missing something here Larry. NFPA 1901 says all 2.5" discharges must flow at least 250 gpm at 150 psi, but do not limit the flow. You can have your pumper piped any way you like as long as you hit the minimums. Point being, you can flow 250 gpm through a 1.5" line off the right discharge. The theoretical friction loss alone would be 150 psi then add your nozzle pressure in, but any class A fire pump will be able to supply the line. Not a good set up, but easily attainable. Heck we just flowed 350 gpm through an 1.75" line using a Vindicator nozzle.1st. NFPA 1901 requires that all 2 1/2 inch fittings on pumping apparatus flow 250 gpm at 150 psig. So you will not be putting 250 gpm through an inch and a half line reguardless of the pressure.
As for the original question? You need to know more information than just the diameter of the hose to determine the flow. The gpm at a given psi of each nozzle is a large factor as well as friction loss in the length of the lay. The best thing you can do is get rid of the automatic nozzles which make all streams "look" great even when they're woefully inadequate.
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