Liquid measurement with orifice meters

While the orifice meter is the most common meter for measuring gas flows, it also has many applications in liquid flow measurement. These applications range from measurement for control purposes only, where flow rate is the important variable, to measurement of dirty or corrosive liquids that would cause excessive maintenance in positive displacement or turbine meters. Liquid metering with orifice meters requires the same equipment tolerances as gas metering. Installation procedures are slightly different, but the same principles apply. Flow calculations are fairly simple for low viscosity liquids. The data and methods referenced in this paper are covered in more detail in Singer Handbook E-2 and in the NGPSA Engineering Data Book.