Valve Calculator
Calculate valve Cv/Kv flow coefficients, pressure drop, flow rates, valve authority, relief valve sizing, and actuator requirements. Get instant engineering calculations based on industry standards.
Calculate Valve Specifications
Calculate valve sizing coefficient for flow control
Water = 1.0
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Valve Types Reference
| Type | Cv Range |
|---|---|
| Globe | 0.01 - 5000 |
| Ball (Full Port) | 1 - 10000 |
| Ball (Reduced) | 0.5 - 5000 |
| Butterfly | 10 - 50000 |
| Gate | 5 - 20000 |
| Plug | 1 - 3000 |
Cf = Pressure recovery factor (lower = higher recovery, more cavitation risk)
Valve Sizing & Selection Guide
Our comprehensive valve calculator helps engineers, technicians, and procurement professionals properly size and select valves for industrial applications. Whether you're specifying a new control valve, verifying pressure drops, or sizing relief valves for safety systems, these calculations follow industry standards including ISA, IEC 60534, and API guidelines.
Key Calculations Included:
- ✓Cv/Kv flow coefficient for liquids and gases
- ✓Pressure drop across valves at given flow
- ✓Flow rate calculation from known Cv
- ✓Valve authority for control applications
- ✓Relief valve orifice sizing (API 520)
- ✓Actuator force and torque requirements
Industry Applications:
- •Oil & gas processing plants
- •Chemical and petrochemical facilities
- •Water and wastewater treatment
- •HVAC and building automation
- •Power generation and steam systems
- •Food and beverage processing
Valve Formulas Reference
Cv (Liquid)
Cv = Q × √(SG / ΔP)
Q = GPM, SG = specific gravity, ΔP = psi
Cv to Kv Conversion
Kv = 0.865 × Cv
Kv in m³/h, Cv in GPM
Pressure Drop
ΔP = (Q / Cv)² × SG
Rearranged Cv equation
Valve Authority
N = ΔPv / ΔPtotal
Target: N = 0.3 to 0.5 for control
Cv (Gas)
Cv = Q×√(SG×T)/(963×P₁)
Subcritical flow, Q in SCFH
Actuator Force
F = ΔP × A × SF
A = seat area, SF = safety factor
Valve Type Selection Guide
| Valve Type | Best Application | Cv Range | Pressure Recovery | Cavitation Risk |
|---|---|---|---|---|
| Globe | Throttling, flow control | 0.01 - 5000 | Low (Cf 0.7-0.9) | Lower |
| Ball (Full Port) | On/Off, low ΔP | 1 - 10000 | High (Cf 0.55-0.7) | Higher |
| Ball (Reduced) | Throttling, moderate ΔP | 0.5 - 5000 | Medium (Cf 0.6-0.8) | Medium |
| Butterfly | Large flows, low ΔP | 10 - 50000 | High (Cf 0.5-0.7) | Higher |
| Gate | On/Off only | 5 - 20000 | Very High (Cf 0.5-0.6) | Higher |
| Plug | Throttling, slurries | 1 - 3000 | Medium (Cf 0.6-0.8) | Medium |
Note: High pressure recovery valves (low Cf) recover more downstream pressure but have higher cavitation potential. Globe valves with low recovery are preferred for high ΔP throttling applications.
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