ASME B16.40:2019 pdf download

ASME B16.40:2019 pdf download.Manually Operated Thermoplastic Gas Shutoffs and Valves in Gas Distribution Systems
1 SCOPE
1.1 General (a) This Standard covers manually operated thermo- plastic valves in nominal valve sizes 1 ∕ 2 through 12. These valves are intended for use below ground in ther- moplastic 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 manu- facturedvalvesforuseinbelow-groundpipingsystemsfor fuel gas [includes synthetic natural gas (SNG)] and lique- fied 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. Itis notconsidered practical to identifythe spe- cific edition ofeach standard and specification in the text. Instead, the specific edition referenced is identified in Mandatory Appendix II. 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 orcalculatedvalueberoundedofftothenearestunitinthe lastright-hand digitused forexpressingthe limit. Decimal values and tolerances do notimply a particular method of measurement.1.4 Relevant Units This Standard states values in both U.S. Customary and SI (metric) units. Thesesystemsofunitsaretoberegarded 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. Combiningvalues 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 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). DR: the dimensional ratio defined as the pipe outside diameter (O.D.) divided by the pipe wall thickness, t. DR = O.D./t. DRv: the valve DR equivalent is the designated valve DR based on the lowestDRofthe pipe ends used in long-term hydrostatic testing under this Standard. ASTM D2513 shall be the standard used for polyethylene (PE) and ASTM F2945 shall be the standard for polyamide 11 (PA-11). fasteners:nuts,bolts,washers,cliprings,andotherdevices used in the assembly of valves. lubricatedvalves: valves that require pressure lubrication (bytheinsertionthroughfittingsoflubricanttothesealing surfaces of the valve) to effect a leak-tight seal. NVS: nominal valve size. pressure: unless otherwise stated, gage pressure. production pressure tests: tests that include seat and closure-member and shell tests. seat and closure-member test: an internal pressure test of closure-sealing elements (seats, seals, and closure members, e.g., gate, disc, ball, or plug). shell test: an internal pressure test of the pressure- containing envelope. valve design pressure: the pressure calculated by the method described in Mandatory Appendix I using the valve shell material’s hydrostatic design basis (HDB) at 73°F (23°C). Parts Other Than the Valve Shell. Parts other than the valve shell that contribute to pressure contain- ment or retaining differential pressure across the closure elementshall be resistantto the gases in para. 1.1(c). Such parts shall be designed to withstand normal valve-oper- ating loads and, in addition, shall provide long-term pres- sure-containmentintegrityconsistentwiththevalveshell. Thesustainedpressure tests ofpara. 6.3.3 shallqualifythe design and material selected for these parts, which include, but are not limited to, the closure member, stems or shafts (if they are designed to retain pressure), and fasteners retaining shell sections.