ASME B16.40:2019 pdf download.Manually Operated Thermoplastic Gas Shutoffs and Valves in Gas Distribution Systems.
1.1 GeneraL
(a) ASME B16.40 covers manually operated thermoplastic valves in nominal valve sizes 1/2 through 12. These valves are intended for use below ground in thermoplastic fuel gas distribution mains and service lines. The maximum operating pressure (MOP) at which such distribution piping systems may be operated is in accordance with Transportation of Natural and Other Gas by Pipeline; Minimum Safety Standards [49 C.F.R., §192 (2017)] for temperature ranges of —20°F to 140°F (—29°C to 60°C).
(b) This Standard sets qualification requirements for each basic valve design as a necessary condition for demonstrating conformance to this Standard.
(c) This Standard sets requirements for newly manufactured valves for use in below-ground piping systems for fuel gas [includes synthetic natural gas (SNG)] and liquefied petroleum (LP) gases (distributed as a vapor, with or without the admixture of air) or mixtures thereof.
1.2 References
Standards and specifications adopted by reference are shown in Mandatory Appendix II, which is part of this Standard. It is not considered practical to identify the specific edition of each standard and specification in the text. Instead, the specific edition referenced is identified in Mandatory Appendix II.
(19) 1.3 Convention
For determining conformance with this Standard, the convention for fixing significant digits where limits (maximum and minimum values) are specified shall be as defined in ASTM E29. This requires that an observed or calculated value be rounded off to the nearest unit in the last right-hand digit used for expressing the limit. Decimal values and tolerances do not imply a particular method of measurement.
(19) 1.4 ReLevant Units
This Standard states values in both U.S. Customary and SI (metric) units. These systems of units are to be regarded separately as standard. Within the text, the SI units are shown in parentheses. The values stated in each system are not exact equivalents; therefore, it is required that each system of units be used independently of the other. Combining values from the two systems constitutes nonconformance with the Standard.
1.5 Definitions
basic valve design: each variation in material, size, or configuration of molded pressure-containing parts that
h constitutes a given valve design, except where minor design variations are produced by differences in machining of the same molded piece(s) to produce different end sizes or dimensional ratios (DRs).ASME B16.40 pdf download.