# Valve Flow Coefficient Cv / Kv

Valve flow coefficient, abbreviared as \(C_v\), also called valve sizing coefficient, a dimensionless number, is the number of US gallons of water at 60°F that will flow throuhg a valve in one minute when the pressure differential across the valve is one pound per square inch (psi).

## Valve Flow Coefficient Cv / Kv Formulas

\(\large{ C_v = Q \sqrt{ \frac{SG}{\Delta P} } }\) |

\(\large{ Q = C_v \sqrt{ \frac{\Delta P}{SG} } }\) |

\(\large{ \Delta P = SG \left( \frac{Q}{C_v} \right) }\) |

\(\large{ K_v = Q \sqrt{ \frac{SG}{\Delta P} } }\) |

\(\large{ Q = K_v \sqrt{ \frac{\Delta P}{SG} } }\) |

\(\large{ \Delta P = SG \left( \frac{Q}{K_v} \right) }\) |

### Where:

Units |
English |
Metric |

\(\large{ C_v }\) = valve flow coefficient (US units) | \(\large{ dimensionless }\) | |

\(\large{ K_v }\) = valve flow coefficient (SI units) | \(\large{ dimensionless }\) | |

\(\large{ Q }\) = valve flow rate | \(\large{\frac{ft^3}{sec}}\) | \(\large{\frac{m^3}{s}}\) |

\(\large{ \Delta P }\) = valve pressure differential | \(\large{\frac{lbf}{in^2}}\) | \(\large{\frac{N}{m^2}}\) |

\(\large{ SG }\) = specific gravity of fluid | \(\large{ dimensionless }\) |

Tags: Pressure Equations Coefficient Equations Flow Equations Valve Equations Valve Sizing Equations