About This App
This app computes the gas flow rate using the orifice plate energy equation. The app follows the standard procedure described in ISO 5167-2. The orifice discharge coefficient is calculated using the Reader-Harris/Gallagher (1998) equation.

This app requires the pipe diameter (D), orifice diameter (d), upstream pressure (P1), the differential pressure across the orifice (P1-P2), downstream temperature (T), gas specific gravity and gas isentropic expansion factor/heat capacity ratio (k=Cp/Cv). The user has the option of specifying the units for each, hence the values can have any mix of units.