Abstract： ASME B16.40:2002 pdf download.MANUALLY OPERATED THERMOPLASTIC GAS SHUTOFFS AND VALVES IN GAS DISTRIBUTION SYSTEMS. In addition, cvidencc shall be presented to dcinonstrate that such materials will perform satisfactorily in fuel gas as liste...

ASME B16.40:2002 pdf download.MANUALLY OPERATED THERMOPLASTIC GAS SHUTOFFS AND VALVES IN GAS DISTRIBUTION SYSTEMS.

In addition, cvidencc shall be presented to dcinonstrate that such materials will perform satisfactorily in fuel gas as listed in

para. 1(c).

2.2.2 Parts Other Than Valve-Shell Parts. Pans other than shell pans. which contribute to pressure conlainnient or to rciaining

differential pressure across the closure element, shall be resistant to the gases in para 1(c). Such parts shall he designed to

withstand normal salve-operating loads and, in addition, shall prnsidc long-term pressure-containment integrity consistent with

salse-shell parts. The sustained pressure tests of par.as.3.3.3(a) and 3.3.3(b) shall qualify the material selections for these

pans, which include, hut arc not limited to. the ck,sure member. stems or shafts (if they are designed to retain pressure). and

fasteners retaining shell sections.

2.2.3 Lubricants and Sealants. Lubricants and scaIiiit’ shall be rcsist.uit to the .iution of gases referred to in para. 1(c).

2.2.4 Responsibility. When service conditions, such as gases having high hydrogen content or compounds likely to form condensate,

dictate special materials considerations, it is the users’ responsibility to specify this information to the manufacturer.

2.3 Configuration

2.3.1 Operating Indication

(a) Valves designated for one-quarter turn operation shall be designed to visually show the open and closed position of the valve. A rectangular stem head or an arrow thereon or a separate position indicator shall indicate the closed position of the salve

port when the longitudinal axis of the stem head or indicator is perpendicular to the axis of the connecting pipe. I a separate

indicator is employed, it shall be designed such that ft cannot he asscnihlcd 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.

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