Control valve sizing is the process of determining the correct valve size and style for a specific application.
Control valve sizing factors
The primary factors that should be known for accurate sizing are:
- The fluid phase (gas, liquid, multiphase) and the density of the fluid (specific gravity, specific weight,
molecular weight). - The valve inlet and outlet pressures at the flow rates being considered.
- The temperature of the fluid.
- Cleanliness of fluid (entrained particule/catalyst).
- The viscosity (liquids).
- The vapor pressure and critical pressure (liquids).
- Specific heat ratio (gas).
- The compressibility factor (gas).
- Flow rates required (maximum, normal, minimum)
- Pressure drop at shutoff
- Maximum permissible noise level, if pertinent, and the measurement reference point
- Inlet and outlet pipe size and schedule
- Start-up conditions, if different than minimum