What do you mean by calibration of orifice plates? Do you mean verification of their flow measurement similar to calibration/proving that is done on turbine meters?
Orifice metering of flowing fluids is one of the most thoroughly documented subjects. ASME has published some superb texts, and numerous other sources are readily available. If your orifice dimensions and adjacent piping configuration are known with sufficient accuracy, the flow characteristics of your system can be determined with reasonably predictable accuracy.
I am sourcing for a Positive Displacement Piston Prover for calibration of Turbine Flowmeters mainly use in Aerospace industries. Could anyone advice me on which are the more reliable Manufacturer. Thank You.