This standard provides a single reference for engineering equations, uncertainty estimations, construction and installation requirements, and standardized implementation recommendations for the calculation of flow rate through concentric, square-edged, flange-tapped orifice meters. Both U.S. customary (USC), and international system of units (SI) units are included.

The standard is organized into four parts. Parts 1 (General Equations and Uncertainty Guidelines), 2 (Specifications and Installation Requirements), and 4 (Background, Development, and Implementation Procedure and Subroutine Documentation) apply to the measurement of any Newtonian fluid in the petroleum and chemical industries. Part 3 (Natural Gas Applications) focuses on the application of Parts 1, 2, and 4 to the measurement of natural gas.