Kv (flow factor)

The flow factor is the metric equivalent of Flow coefficient.

In more practical terms, the flow factor Kv is the rate of flow of cold water in cubic metres per hour at a pressure drop of one kilogram per square centimetre across the valve.[1]

Kv can be calculated using:

K_v = F \sqrt{\dfrac{SG}{\Delta P}}

where:
Kv = flow factor
F = Rate of flow (cubic meters per hour).
SG = Relative Specific gravity of fluid with reference to water(Water = 1).
ΔP = Pressure drop across valve (1 bar or 100kPa).

Kv is commonly used in Europe and Asia. Kv can be calculated using the equation [2]

{K_v} = (0.865)({C_v})

References

  1. ↑ ISBN 978-1-4005-2712-0 Flow of fluids through valves and fittings, Crane Co.
  2. ↑ Control Valve Handbook Search Chapter 5.