GPM calculation on 8" pipe...
GPM calculation on 8" pipe...
(OP)
How would I calculate GPM on an 8"water main. We recently broke a water main and I mean it BROKE! Major flood in our basement. I want to look into sizing up our sump system but want to know the max capabilities of our domestic water output. I am only looking for a rough estimate. Here are the specs...
Water PSI is about 110-115 and that is about where the break happened... so psi loss is not a factor and the pipe is 8"
Water PSI is about 110-115 and that is about where the break happened... so psi loss is not a factor and the pipe is 8"





RE: GPM calculation on 8" pipe...
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com
RE: GPM calculation on 8" pipe...
The conditions of the break and the surrounding materials would also have an effect. For a robust distribution system at 110 psi, I would expect the break to put out somewhere about 5,000 gpm.
RE: GPM calculation on 8" pipe...
RE: GPM calculation on 8" pipe...
RE: GPM calculation on 8" pipe...
RE: GPM calculation on 8" pipe...
RE: GPM calculation on 8" pipe...
Under normal operating static pressure at the break, I had a guage that read 110-115. The break was at a PVC flange fitting and broke the entire circumfrence of the fitting. The supply was domestic water from the city and it took me about 20 minutes to turn the water off at the meters. I couldn't see the break while the water was flowing because the room it was in had so much water in it and we couldn't force the water back by pushing on the door with three guys.
good times... and thankful for insurance since my domestic water pumps and controls got submurged.
RE: GPM calculation on 8" pipe...
More realistic is around 10 fps in the 8" pipe giving 1500 gpm. But this really is a "how long is a piece of string?" question.
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com
RE: GPM calculation on 8" pipe...
RE: GPM calculation on 8" pipe...
I understand what you are saying Katmar.
Thanks for all of your help.
As for the PVC fitting... well it is for a Sterling water conditioner. Not sure if I want to put another one in. I haven't been convinced of its performance in the first place.
Thanks to everyone for your help... I kind of have a better idea of what kind of water was lost.
Matt
RE: GPM calculation on 8" pipe...
rmw
and PS: the client being demonstrated to didn't buy our machine.
RE: GPM calculation on 8" pipe...
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com