ASME B16.40 (2002)
Manually Operated Thermoplastic Gas Shutoffs and Valves in Gas Distribution Systems
Annotation and contents
This Standard covers manually operated thermoplastic valves in nominal sizes 1/2 through 6. These valves are suitable for use below ground in thermoplastic distribution mains and service lines. This Standard sets qualification requirements for each nominal valve size for each valve design as a necessary condition for demonstrating conformance. This Standard sets requirements for newly manufactured valves for use in below ground piping systems for natural gas [includes synthetic natural gas (SNG)], and liquefied petroluem (LP) gases (distributed as a vapor, with or without the admixture of air) or mixtures thereof. Standards and Specifications referenced under this Standard are shown in Appendix II. For the purpose of determining conformance with this Standard, the convention for fixing significant digits, where limits maximum or minimum values are specified, shall be "rounding off" as defined in ASTM Practice E 29. This requires that an observed or calculated value shall 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.