The capacity of one foot of a pipe with an inner diameter of 20 inches is approx 1.36 US gallons. The maximum amount of water is, therefore, 1.36 gallons, but there need not be any water in the pipe.
36.83 u.s. gallons of water in 1 ft. of 30" pipe
In a pipe with diameter 8 ft, there will be just over 376 US gallons per foot.
31.987 gallons per foot.
There need not be any water at all in the pipe. The capacity of the pipe is approx 3.4 Imperial gallons.
0.255 gallons per foot of pipe. A 10 ft long pipe that size holds 2.55 gallons.
A three-inch diameter pipe one foot long holds 0.367 gallon.
much water per foot will a 5 inch pipe hold
0.212 331 gallons per foot.
0.61 * d2 Where d is the diameter of the pipe in inches.
A 12 inch diameter round pipe will hold 4.89 UK gallons or 5.88 US gallons per foot.
For a 3 foot diameter pipe, 52.9 US gallons per foot of length.
It will hold 477.4 gallons of water per 1,300-foot section.