1. (1) The differential, static pressure and temperature recording gauges, integrating mechanism, and other pertinent components shall be tested annually.
2. (2) Periodic inspections of meter tubes and orifice plates, no less frequent than annually, shall be scheduled to insure compliance with original installation specifications.

(a) General conditions.

Orifice meters shall be installed to comply with American Gas Association Report No. 3, Orifice Metering of Natural Gas and Other Related Hydrocarbon Fluids, Third Edition, Part 1 General Equations and Uncertainty Guidelines (1990), Part 2 Specification and Installation Requirements (1991), Part 3 Natural Gas Applications (1992), and Part 4 Background, Development, Implementation Procedure, and Subroutine Documentation for Empirical Flange-Tapped Discharge Coefficient Equation (1992), available from American Gas Association, 1515 Wilson Boulevard, Arlington, VA 22209-2470.

(b) Test and inspection programs.