To operate at 2 ft/sec with a 20 GPM pump, what diameter cylinder would you need?

To determine the diameter of the cylinder needed to operate at a specific speed and flow rate, we can use fluid power principles, particularly the relationship between flow rate, cylinder area, and piston speed.

The flow rate of a pump, measured in gallons per minute (GPM), indicates how much hydraulic fluid is available to actuate the cylinder. In this scenario, the pump delivers 20 GPM. To convert GPM to cubic feet per second for easier calculations, note that 1 GPM is approximately 0.002228 cubic feet per second (CFS). Therefore, 20 GPM converts to about 0.04456 CFS.

For cylinders, the relationship between flow rate (Q in cubic feet per second), piston speed (V in feet per second), and cylinder area (A in square feet) is given by the equation:

Q = A × V.

Rearranging this allows us to solve for area:

A = Q / V.

Using the values provided:

• Q = 0.04456 CFS,

• V = 2 ft/sec,

we can calculate the required area:

A = 0.04456 CFS / 2 ft/sec = 0.02228 square