ASME B16.38 pdf download Large Metallic Valves for Gas Distribution Manually Operated, NPS 2 1 / 2 (DN 65) to NPS 12 (DN 300), 125 psig (8.6 bar) Maximum
2.3.1 Closure Indication
22.214.171.124 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 or a position indicator shall indicate the closed position of the valve port when the longitudinal axis of the stem head or indicator is perpendicular to the axis of the connecting pipe. If a separate indicator is employed, it shall be designed such that it cannot be assembled to incorrectly indicate the position of the valve.
126.96.36.199 Valves shall close by clockwise stem rotation unless otherwise specified by the purchaser or by the reference standard in para.
2.1.2. The direction for closing shall be indicated.
2.3.2 Valve Ends. Valve ends shall conform to the following standards where applicable:
(a) for threaded valve ends, ANSI/ASME B1.20.1
(b) for flanged gray cast iron valve ends, ASME B16.1
(c) for flanged ductile cast iron valve ends, ASME B16.42
(d) for flanged steel valve ends, ASME B16.5
(e) for flanged, butt-welding, and socket-welding valve ends, ASME B16.34 2.3.3 Dimensions. Face-to-face and end-to-end dimensions of valves (other than ball, butterfly, or dia- phragm valves) with flanged ends or butt-welding ends shall conform to the dimensions contained inMSS SP-72. Face-to-face dimensions for butterfly valves shall be in accordance with dimensions contained in MSS SP-67. End-to-end dimensions of threaded end valves shall be in accordance with the manufacturer’s standard dimensions.
2.4 Marking Each valve, in addition to the markings required by the applicable valve standard of para. 2.1.2, shall bear the marking “B16.38” or “B16.38T” if tamperproof features are included according to para. 2.2. Alternative to the latter, the marking “T” may be shown on the operating head or stem.
2.5 Injection Sealant A valve that utilizes injection of sealant through a fitting that leads to the sealing surfaces shall be capable of having sealant injected in both the full-open and -closed positions at an inlet pressure of125 psig (8.6 bar).
2.6 Pressure-Containing Materials Materials for valve bodies, plugs, bonnets, unions, and other pressure-containing parts shall be in accor- dance with the applicable standards of para. 2.1.2.