Control Valve Sizing

ISA/IEC 60534 Cv sizing for liquids and gases with choked flow detection

Fluid Type

Process Conditions

P₁ (bar abs)

P₂ (bar abs)

Temperature (°C)

ΔP = 3.00 bar

Liquid Properties

Flow Rate (m³/h)

Specific Gravity Gf

Water = 1.0

Vapor Pressure (bar)

Pc (bar, optional)

Water = 221.2

FL (Recovery Factor)

Results

Required Cv

57.7350

Flow Rate

100.0000 m³/h

ΔP Used

3.000 bar

ΔP Max

7.717 bar

Sub-critical

FF (pressure ratio factor): 0.9467

FL: 0.90

x = ΔP/P₁ = 0.3000 | x_choked = Fk·xT = 0.7000

Quick Reference

Q = Flow (m³/h)

Cv = Flow coefficient

Gf = Specific gravity (water=1)

SG = Specific gravity (air=1)

FL = Liquid pressure recovery

xT = Terminal pressure drop ratio

FF = Liquid critical pressure ratio

Y = Expansion factor (≥0.667)