Inputs
Use a calibrated or applicable vendor coefficient. 0.98 is an example.
Results
Choose your inputs and calculate.
Calculation basis
β = d/D; At = πd²/4 Q = Cd At √[2ΔP / (ρ(1 − β⁴))] ΔP = (ρ/2)(Q/(Cd At))²(1 − β⁴) Throat diameter is obtained by rearranging the same equation.
How to use this calculator
Enter the pipe ID, throat diameter, density, and the discharge coefficient for your meter. Select flow or differential pressure, or solve a throat diameter for a target liquid flow. Cd depends on geometry and operating conditions; verify its validity with the meter manufacturer.
Single-phase incompressible liquid, full pipe, pressure taps at the same elevation. The inlet-to-throat differential is not the permanent pressure loss. This tool does not select an ISO 5167 coefficient or calculate gas expansibility.
References
Explore all engineering tools · Pipe pressure drop calculator