ASME B16.40 pdf download Manually Operated Thermoplastic Gas Shutoffs and Valves in Gas Distribution Systems
2.1 General (a) The workmanship used in the manufacture and assemblyofeachvalveshallprovide gas tightness, safety and reliability of performance, and freedom from injuri- ous imperfections and defects. (b) Design details not addressed in this Standard are the responsibility of the manufacturer.
2.2.1 Valve Shell. The pressure-containing valve shell shall be made from either polyethylene (PE) or polyamide 11 (PA-11) materials specified in and quali- fied to the requirements for pipe and fittings as listed in ASTM D 2513.
2.2.2 Parts Other Than the Valve Shell. Parts other than the valve shell, which contribute to pressure con- tainment or retaining differential pressure across the closure element, shall be resistant to the gases in para. 1.1(c). Such parts shall be designed to withstand normal valve-operating loads and, in addition, shall provide long-term pressure-containment integrity consistent with the valve shell. The sustained pressure tests ofpara. 6.3.3 shall qualify the 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.
2.2.3 Lubricants and Sealants. Lubricants and seal- ants shall be resistant to the action of gases referred to in para. 1.1(c). Lubricated valves, as defined in para. 1.5, are not within the scope of this Standard. 2.2.4 Responsibility. When service conditions, such as gases having high hydrogen content or compounds likely to form condensate, dictate special materials con- siderations, it is the users’ responsibility to specify this information to the manufacturer.
3.1 Operating Indication
(a) Valves designed for one-quarter turn operation shall be designed to visually show the open and closed position of the valve. A rectangular stem head with an arrow thereon or a separate position indicator shall indicate the closed position of the valve port when the longitudinal axis ofthe stem head or indicator is perpen- dicular to the axis of the connecting pipe. If a separate indicator is used, it shall be designed such that it cannot be assembled to incorrectly indicate the position of the valve.
(b) Valves designed for more than one-quarter turn operation shall close by clockwise stem rotation, unless otherwise specified by the user. The direction for closing the valve shall be indicated.
3.2 Valve End Design Valve ends shall be designed to one or more of the following, unless otherwise specified by the user: (a) PE or PA-11 valve stub-ends that conform to the applicable dimensions ofASTMD3261, F1733,orD2513 (b) polyethylene socket ends that conform to the applicable dimensions listed in Tables 1 and 2 of ASTM D 2683 (c) integral mechanical joints that meet the require- ments of the applicable paragraphs under CFR, Title 49, Part 192, Subpart F, Joining of Material Other Than by Welding
4 PRESSURE RATING
4.1 Maximum Pressure Rating The maximum pressure rating of each valve is the valve design pressure as defined in para. 1.5 for service from −20°F to 140°F (−29°C to 60°C).
4.2 Design Pressure The design pressure of the valve shall be limited to the maximumservice pressure permitted forplastic pipe as specified in 49 CFR, Part 192.123.
5 MARKING Each valve shall be clearly marked to show the fol- lowing:
(a) the manufacturer’s name or trademark.
(b) the designation B16.40.
(c) the NVS.
(d) the pressure shell material designation code as specified in ASTM D 2513.
(f) each molded pressure shell part shall be marked with the date it was molded. Valve shells that are not molded shall be stamped with the date of manufacture using low-stress stamping. The markings specified in paras. 5(a) and (f) shall be permanently affixed to or be incorporated as part of the permanent valve identification. Other markings may be affixed to the valve by any means, provided they do not impair the structural integ- rity or the operation of the valve.