ANSI B109.3:2000 pdf download.ROTARY-TYPE GAS DISPLACEM ENT METERS .
This part establishes the construction requirements for the qualification of a new-type rotary meter.
2.2 DIMENSIONS
The following standard specifications are included to provide for practical mounting and connecting interchangeability, consistent with accepted manufacturing procedures.
2.2.1 Meter Piping Connection. Meter piping connections shall conform dimensionally with the flange class specifications in the “Standard for Cast Iron Pipe flanges and Flanged Fittings,” ANSI/ASME B 16.1-1989, or “Standard for Steel Pipe Flanges and Flanged Fittings,” ANSVASME B16.5-1988, or threaded connection specifications in the “Standard for Pipe Threads (Except Dryseai), General Purpose (inch),” ANSI/ASME B1.20.1, for gas transmission and piping systems.
2.2.2 ConnectIon Tolerances. Meter connections shall conform to the face-to-face tolerance limits specified (Dimension A, Figure 1; Dimensions A and B, Figure 2). The axis of the inlet and outiet connections shall be concentric within 1/16 inch (1.6 mm). (Dimension C, Figures 1 and 2.)
2.2.2.1 Range Connections. The flange faces shall be parallel with each other and perpendicular to an axis through the center of each, to within I degree (0.017 rad). (Dimension 13, Figure 1.)
2.2.2.2 Threaded Connections. Meters with threaded connections (pipe nipples or threaded) shall be checked for concentricity with pipe nipples, installed as iflustrated in Figure 2.
2.3 MAXIMUM ALLOWABLE OPERATING PRESSURE (MAOP)
The MAOP shall be the maximum working pressure as determined by the manufacturer using the guidelines set forth in Section VIII of the ASME Boiler and Pressure Vessel Code. The pressure rating of the meter shall no exceed the MAOP of the meter or the flange connection, whichever is less.
2.4 STRENGTH OF METER CONNECTIONS
The meter connections shall be constructed to provide adequate strength in connecting the meter to related piping systems.
Method of Test
Tests for determining the strength of meter connections shall be performed with a device constructed to provide (1) a lever arm of predetermined length to which a force can be applied in a perpendicular plane for performing torsional and bending moment tests, (2) a pressure tigbt connection at meter connections, and (3) a pressure tap for connecting a manometer or pressure gauge.
Tests shall be applied in the following sequence:
a. The meter shall be tested for accuracy at 20 percent of its rated capacity near atmospheric pressure.
b. A bending moment shall be applied according to Table I and the pressure raised to 5% and then to 100% of the MAOP. There shall be no leakage under either of these conditions of stress and pressure for a minimum penod of 1 minute.
c. The meter shall then be retested for accuracy as in “a” above while subjected to the san bending moment. The two accuracy measurements shall not differ by more than 0.25%.ANSI B109.3 pdf download.