Orifice Plates is a primary flow element in which a circular aperture has machined.General Applications – Gas, Liquids, Vapors etcLimits of use d > = 12.5mm, Pipe line 2” and above, Beta Ratio > = 0.2 & < = 0.75 ReD > = 5000 for 0.2 – 0.45 beta & > = 10000 for beta > 0.45 – For corner tapping ReD > = 1260*beta2*D for Flange Taps