Answer: .25 gallon
Math:
Volume of a cylinder = pi * R2 * h
pi * 1.52 * 12 = 57.3 cubic inches
231 cubic inches in 1 gallon
57.5/231= .25 gallon (or one quart)
if 3/4 in. is the diameter, you would need 410 2/3 feet of pipe
nominal 3/4 in. type K copper pipe - 132 1/2 feet holds 3 U.S. Gallons
nominal 3/4 in. type L copper pipe -119 1/3 feet holds 3 U.S. Gallons
A pipe is a cylinder and the volume of a cylinder is it's radius squared X pie X it's height. 12 inches of 10" pipe would hold more water than 12 inches of 1" pipe. In the same way 12" of 3 inch pipe would hold more water than 1 inch of pipe 3" in diameter. So what you're missing in this equation is; how long is the pipe?
Once you figure out the volume of the pipe, you'll have to convert that amount into gallons. If you're measuring the pipe in inches your end answer will be in cubic inches, you might be hard pressed to find a conversion table for that. Maybe not.
U.S.Gallons of water per foot = volume in cu. in. divided by 231 cu. in.(for U.S.gal)
= (Pi/4 x 32 x 12) / 231 = 0.3672 U.S. gal per foot of 3 inch pipe.
Just under a gallon .9>>>>>>
A 3" x 100' pipe holds 36.7 gallons of water.
pir2 x300 3.14x 1.5x200= 942
43.6 feet of 3/4-inch pipe.
half a pint
This cylinder will hold up to 3,760.11 gallons of water.
141.06 gallons
A 15 cubic foot tank will hold a maximum of about 112.2 gallons of water.
A three-inch diameter pipe one foot long holds 0.367 gallon.
About 14,351 US gallons of water.
700 gallons
You haven't said how deep it is. To measure volume you need three dimensions.
If you filled it all the way to the top it would be holding about 15,594 gallons of water. If you filled it to three feet deep, it decreases to around 10,200 gallons.
17,000 gallons
0.212 331 gallons per foot.
A pool this size will hold about 21,544 gallons of water.