ASME B16.33:2012 pdf download.Manually Operated Metallic Gas Valves for Use in Gas Piping Systems Up to 175 psi.
3.2.3.3 Compression Set Tests. Elastomer parts that may be exposed to fuel gas shall be made from materials having a compression set of no more than 25% after 22 hr at 212°F (100°C), in accordance with ASTM D395, Method B, using standard test specimen in accordance with ASTM D395, para. 5.2..
3.2.4 Polytetrafluoroethylene (PTFE) Components.
PTFE materials shall comply with ASTM D4894 or ASTM D4895.
4 DESIGN QUALIFICATION
4.1 General
4.1.1 Each basic valve design shall be qualified and demonstrated as suitable for the seiice by testing randomly selected production valves of each size, type, and pressure shell material according to the design qualification tests required by this section.
4.1.2 All tests, unless otherwise specified, shall be conducted at a temperature of 74°F ± 15°F (23°C ± H°C).
4.1.3 Before each test is conducted, the valve shall he in the condition in which it would he placed in service.
4.2 Gas Tightness
4.2.1 The valve shall provide a shutoff when in the closed position and shall not leak to the atmosphere in the open or closed position when sublected progres. sively to internal air pressure of first 4 psi ± 2 psi (0.3 bar ± 0.1 bar) and then to at least 1.5 times the pressure rating of the valve.
4.2.2 Method of Test for Gas Tightness. With the valve in the open position and the outlet plugged, the test pressure shall be applied to the inlet of the valve. The valve shall be immersed in a bath containing water at a temperature of 74°F ± 15°F (23°C ± 8°C) for a period of 15 sec. Leakage, as evidenced by flow (breaking away) of bubbles shall be cause for rejection. The valve shall then be turned to the closed position, outlet opened and the test repeated.
4.2.3 Other means of leak detection may be used provided they can be shown to be equivalent in leak detection sensitivity.
3.2.4 Polytetrafluoroethylene (PTFE) Components.
PTFE materials shall comply with ASTM D4894 or ASTM D4895.
4 DESIGN QUALIFICATION
4.1 General
4.1.1 Each basic valve design shall be qualified and demonstrated as suitable for the seiice by testing randomly selected production valves of each size, type, and pressure shell material according to the design qualification tests required by this section.
4.1.2 All tests, unless otherwise specified, shall be conducted at a temperature of 74°F ± 15°F (23°C ± H°C).
4.1.3 Before each test is conducted, the valve shall he in the condition in which it would he placed in service.
4.2 Gas Tightness
4.2.1 The valve shall provide a shutoff when in the closed position and shall not leak to the atmosphere in the open or closed position when sublected progres. sively to internal air pressure of first 4 psi ± 2 psi (0.3 bar ± 0.1 bar) and then to at least 1.5 times the pressure rating of the valve.
4.2.2 Method of Test for Gas Tightness. With the valve in the open position and the outlet plugged, the test pressure shall be applied to the inlet of the valve. The valve shall be immersed in a bath containing water at a temperature of 74°F ± 15°F (23°C ± 8°C) for a period of 15 sec. Leakage, as evidenced by flow (breaking away) of bubbles shall be cause for rejection. The valve shall then be turned to the closed position, outlet opened and the test repeated.
4.2.3 Other means of leak detection may be used provided they can be shown to be equivalent in leak detection sensitivity.
