Gallons of water in pipe

if you have a 20' length of 12" PVC pipe How much water would it contain?
this is the calculation that I am using is it correct?
0.785X1X20=15.7 (Cubic Feet)
15.7X7.48 (Gallons In a Cubic Foot)=117.436

[Mrs X]

Originally Posted by Unregistered

if you have a 20' length of 12" PVC pipe How much water would it contain?
this is the calculation that I am using is it correct?
0.785X1X20=15.7 (Cubic Feet)
15.7X7.48 (Gallons In a Cubic Foot)=117.436

Hi,

The formula for the volume of a tube or cylinder is pi r² times length. You need to have all the units the same, though. Radius is half the diameter.

If you start with feet, then the equation is:

0.5² x 3.1416 x 20 = 15.71f³

There is 7.480 US gallons in a cubic foot, so you have:

15.71 x 7.480 = 117.5 gallons - Bingo!

20 inch pipe, 41 km ,how much of volume water will be there in gallon

[JohnS]

Originally Posted by mohammed

20 inch pipe, 41 km ,how much of volume water will be there in gallon

You can't work in mixed units. Either convert 20" to meters (see below) or convert 41 km to inches and note that 1 (US) gallon =231 in³; also note Imperial gallons are a different size.

20" x 0.0254 m/in = 0.508 m

Volume of a cylinder, V = (pi/4)*d²*h
(be sure you are using inside diameter of the pipe)
= 0.785 * 0.508² * 41000 = 8310 m³ (8.31 megaliters)

A US gallon is about 3.7854 L, so about 2.2 million gallons
(divide by 1.2 for approximate Imperial gallons)

You can also use diam. x diam. x length x 5.9

1.0 x 1.0 x 20 x 5.9 = 118 gallons.

[JohnS]

Originally Posted by Unregistered

You can also use diam. x diam. x length x 5.9

1.0 x 1.0 x 20 x 5.9 = 118 gallons.

Just to be clear, diameter and length must be feet to apply this formula. The constant, 5.9, is a rounded value for (pi/4)*(1728/231), where the second term is number of gallons in 1 cubic foot.

If i have 500 gallons...,what will be the measurement of the pipe using?

How much water contain in 8" Pipe of 91 Mtrs. Length.

[JohnS]

Originally Posted by Bipin Kumar Roy

How much water contain in 8" Pipe of 91 Mtrs. Length.

You must use consistent units. Since 1 L = 1 dm³, decimeters may be the easiest choice. 91 m = 910 dm, 8" = 2.032 dm

V = (pi/4)*D*D*L = 3.14159/4 * 2.032 * 2.032 * 910 dm³ = 2951 L

I'm trying to figure out a pvc pipe gas tank for a homemade boat. If I use 6' pipe, 2' long my calculations using the second method diaxdiaxlengthx5.9, I come up with 2.95 gallons. Correct?