There is no such thing as a cubic gallon unless you happen to live in a hyper-space with 9 linear dimensions. For us normal human beings, who live in just 3 dimensional space, the answer is 0.283 Imperial gallons.
816 gallons per 800 feet of 5-inch pipe.
A 72-inch pipe 16 feet long holds up to 3,384.1 US gallons of water.
14.7 gallons of water.
111 gallons of water.
12,239.9 gallons of water per 3,000 feet.
5.5 gallons per 15 feet of 3-inch pipe.
1.6 gallons of water.
Up to 1,795.2 gallons of water.
6.5 US gallons of water.
65.3 gallons or 8.7 cubic feet.
40.8 gallons of water per 10 feet of length.
This pipe will hold 1,468.8 gallons of water.
45.9 US gallons.