Fluid and Piping Calculations
0.3208 x GPM ÷ Internal Area
What is the velocity of 10 gpm going through a 1/2" diameter
schedule 40 pipe?
GPM = 10
Internal Area = .304 (see note below)
0.3208 x GPM ÷ Internal
Area = .3208 x 10 ÷ .304 = 10.55 feet per second
Note: The outside diameter of pipe remains the
same regardless of the thickness of the pipe. A heavy duty pipe has
a thicker wall than a standard duty pipe, so the internal diameter
of the heavy duty pipe is smaller than the internal diameter of a
standard duty pipe. The wall thickness and internal diameter of
pipes can be found on readily available charts.
Hydraulic steel tubing also maintains the same outside diameter
regardless of wall thickness.
Hose sizes indicate the inside diameter of the plumbing. A 1/2"
diameter hose has an internal diameter of 0.50 inches, regardless
of the hose pressure rating.
Suggested Piping Sizes:
- Pump suction lines should be sized so the fluid
velocity is between 2 and 4 feet per second.
- Oil return lines should be sized so the fluid velocity is
between 10 and 15 feet per second.
- Medium pressure supply lines should be sized so the fluid
velocity is between 15 and 20 feet per second.
- High pressure supply lines should be sized so the fluid velocity
is below 30 feet per second.
This company assumes no liability for errors in
data nor in safe and/or satisfactory operation of equipment
designed from this information.