Plant engineering calculator · Updated 17 September 2026
Boiler Feedwater Control Valve Cv Calculator — Required Cv, Margin & Pressure Drop
Estimate liquid control-valve Cv for boiler feedwater from flow, specific gravity and available valve pressure drop, then apply a selectable design margin and report pressure-drop share.
Inputs
Live results
- Required Cv 80.096903
- Cv with margin 96.116284
- Valve ΔP share 16.666667%
- Flow 440.28675 US gpm
- Valve ΔP 29.007548 psi
Formula and method
Cv=Q(gpm)×sqrt(SG/ΔP(psi)); selected Cv=Cv×(1+margin).
Worked example
100 m³/h water across 2 bar needs a base Cv near 57 before selection margin.
Engineering assumptions and limits
- Uses the standard incompressible turbulent-liquid Cv screening equation.
- Final valve sizing must check cavitation, flashing, noise, rangeability, reducers and IEC 60534/ISA sizing factors.
Frequently asked questions
What does this Boiler Feedwater Control Valve Cv Calculator calculate?
Estimate liquid control-valve Cv for boiler feedwater from flow, specific gravity and available valve pressure drop, then apply a selectable design margin and report pressure-drop share.
Is this a final equipment selection?
No. Use the result for engineering screening, then verify vendor data, controls, operating cases, codes and project design criteria.
Why does the calculator show intermediate values?
Intermediate values expose the governing load and assumptions, making bad units or unrealistic operating conditions easier to spot before selection.