Check Valve Flow Velocity Calculator

Swing check valves require a minimum amount of flow, so that the valve functions correctly. If the flow through a check valve is not sufficient to hold the disc in a full open and stable position, the disc and associated internal parts will be in a constant state of motion (wobble). This type of installation results in premature wear, noisy operation, and vibration.

Use the following calculators for the type of check valve desired and enter the normal flowrate and nominal pipe size to find the velocity. A resulting velocity less than what is recommended will appear red and further investigation should be done to size the valve and piping appropriately, such as reducing the size of the check valve and adjacent piping.

As a rule, for water systems, Milwaukee Valve recommends a minimum velocity of 7.5 ft/sec for swing type check valves and 4 ft/sec for center guided silent checks. The following calculations assume water with a density of 62.34 lb/ft3

Type of Valve:
Q: Gallons Per Minute
Nominal Pipe Size (std wt):
Velocity: Feet/Second

Q = flowrate in gallons per minute
Pipe Size (Std Wt Steel)

While Milwaukee Valve may make recommendations from time to time regarding valve applications based on our experience, the final selection of valve type, valve configuration(s) and material(s) is the responsibility of the end user or his engineering designee.