Control Valve Sizing

Control Valve terminology, bodies, trim, flow characteristics, Cv and Kv sizing, noise, actuators, positioners and more.

ParameterUnitDescriptionTypical Range
Cv (Flow Coefficient)gpm/√psiFlow capacity in US gallons per minute at 1 psi pressure drop0.01 - 1000
Kv (Flow Coefficient)m³/h/√barFlow capacity in cubic meters per hour at 1 bar pressure drop0.001 - 100
Flow Rategpm or m³/hActual fluid flow rate through the valveVariable
Pressure Droppsi or barPressure difference across the valve0.5 - 50
Valve AuthorityDimensionlessRatio of pressure drop across valve to total system pressure drop0.25 - 1.0
Noise LeveldBSound pressure level generated by the valve60 - 90
Actuator SizeVariousPneumatic or electric actuator capacityDepends on valve type
RangeabilityDimensionlessRatio of maximum to minimum controllable flow20:1 - 100:1
Pressure Ratingpsi or barMaximum design pressure for the valve body150 - 10000
Temperature Rating°C or °FOperating temperature range-50 to 500°C