The answer depends on the units used for the diameter of the pipe. And since you have not bothered to share that crucial bit of information, I cannot provide a more useful answer.
4
4.
2.61153 gallons.
0.3672 gallon per foot of pipe.
A three-inch diameter pipe one foot long holds 0.367 gallon.
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)
31.987 gallons per foot.
much water per foot will a 5 inch pipe hold
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.
375.7952 gallons per foot of 96" pipe