Liquid Control Valve Sizing Calculator

This calculator is used to size liquid control valves.  The calculator determines the valve flow coefficient (Cv) required for a specified liquid flow rate and pressure drop.  The calculator can handle non-flashing and flashing liquid flow. The calculation method is based on the International Electrotechnical Commission procedure described in the Emerson Control Valve Handbook.

Liquid Control Valve Sizing Calculator Guide

Show Instructions

The calculator determines the valve flow coefficient (Cv) required for the valve to pass a specified liquid flow rate with specified upstream and downstream pressures.

The calculator can handle non-flashing, flashing and choked flow.

  1. Enter the mass flow rate of liquid the valve must pass
  2. Enter the pressures upstream and downstream of the valve
  3. Enter the fluid physical properties
  4. Enter the valve liquid pressure recovery factor
    • This can be obtained from valve manufacturer's literature
    • Typical values for globe valves range from 0.70 to 0.97
  5. Enter the piping geometry factor
  6. Click the "Calculate" button
  7. The calculator will determine the valve Cv
  8. The calculator will also determine if the flow is critical or not through the valve