In April of 2000, revisions to the specification and installation requirements for orifice meters was published by the American Gas Association in the form of the AGA Report No. 3 – Part 2, Fourth Edition. This purblication is also correctly known as API 14.3, Part 2, ANSI/API 14.3, Part 2-2000 and GPA 8185, Part 2. This report applies to fluids that are considered to be clean, single-phase, homogenous and Newtonian measured using concentric, square edged, flange-tapped orifice meters.The requirements for the construction of orifice meter tubes, as defined in this publication, will be discussed in greater detail throughout this paper