0.3672 gallon per foot of pipe.
A 12 inch diameter round pipe will hold 4.89 UK gallons or 5.88 US gallons per foot.
231 cubic inches. So 0.832674 Gallons.
Over 9,000.
Pipe is generally cylindrical and the dimension refers to the inside diameter. One cubic foot contains 7.48 gallons. The volume of a one foot long 20" diameter pipe is: pi(1.667/2)^2 = 2.18 cubic feet. At 7.48 gallons per cubic foot the total volume is 16.3 gallons.
2.61153 gallons.
One foot of 3 inch pipe will hold approximately 0.625 gallons of water.
0.3672 gallon per foot of pipe.
A 12 inch diameter round pipe will hold 4.89 UK gallons or 5.88 US gallons per foot.
36.7 US gallons.
36.7 US gallons.
0.6528 gallon per foot (rounded)
36.83 u.s. gallons of water in 1 ft. of 30" pipe
0.255 gallons per foot of pipe. A 10 ft long pipe that size holds 2.55 gallons.
0.212 331 gallons per foot.
231 cubic inches. So 0.832674 Gallons.
There need not be any water at all in the pipe. The capacity of the pipe is approx 3.4 Imperial gallons.