Kv and Cv in valves and gas regulators: what they mean for flow and pressure drop

Kv and Cv coefficients are used to describe the flow capacity of a valve or other component.

What they indicate

A larger coefficient generally means that the component can pass a larger flow with a lower pressure drop, under specific conditions.

Why they are useful

They assist in sizing solenoid valves, regulators, and control valves.

Kv/Cv is not enough on its own

For natural gas, inlet pressure, outlet pressure, density, and compressibility must be taken into account.

Practical conclusion

A component with a small flow coefficient can become a significant restriction under high load.