ASME B16.44-2012 pdf – Manually Operated Metallic Gas Valves for Use in Aboveground Piping Systems Up to 5 psi
ASME B16.44-2012 pdf – Manually Operated Metallic Gas Valves for Use in Aboveground Piping Systems Up to 5 psi.
3.3 Seating and Stem Seal Materials
3.3.1 Etastomer Components — Air Aging. Eiastomer parts that are exposed to fuel gas shall he made from materiak that, following 70-hr air aging in accordance with ASTM D573 at 2IrF (100°C). meet the elongation. tensile and hardness property requirements of paras. 33,1,1 and 126.96.36.199.
188.8.131.52 Tensile tests shall be conducted on six dumbbells in accordance with ASTM D412. Three dumbbells shall be air aged 70 hr in accordance with ASTM 1)573 at 212°F (100°C). The dumbbells shall have a thickness of 0.00 in. ± 0.000 in. (2.0 mm ± 0.2 mm). The average of the three individual tests for the aged dumbbells shall exceed 60% retention of ultimate elongation and (iO% retention of tensile strength at break. The average of the three individual tests for the non- aged dumbbells shall be the basis for percent retention cakubtion.
184.108.40.206 Hardness tests shall be conducted using specimens in accordance with ASTM D395. Type 2. Three specimens shall be air aged 70 hr in accordance with ASTM 1)573 at 212°F (100°C). The average of the three individual tests for the aged specimens shall not show a hardness change of more than t 10 Shore hardness points relative to the average hardness 04 the non-aged specimens.
3.3.2 Elastomer Components — Swell Test. Elastomcr parts that are exposed to fuel gas shall be made 1mm materials that, after 70-hr exposure in n-hexane at
73°F (23°C), in accordance with ASTM LM7I, meet the volume change, elongation, and tensile property ftxIuireIfleIlts of paras. 220.127.116.11 and 18.104.22.168.
22.214.171.124 Volume change tests shall be conducted using six specimens in accordance with ASTM D47L Section 8. Three specimens shall be exposed for 70 hr at 73’F (23°C) in n-hexane in accordance with AS1M D471. The average of the three individual ri.hexane tests shall not show an increase in volume of
126.96.36.199 hall be conducted on six dumbbells in accordance with ASTM 1)412. Three of the tensile tests shall be conducted on dumbbells exposed in n-hcxane at 73F (23°C) for 71) hr in accordance with ASTM D471 The dumbbells shall have a thickness of 0.08 in. ± 0.008 in. (2.0 mm ± 0.2 mm), The average of the three individual n-hexane tests shall exceed 60% retention of ultimate elongation and 60’.. retention of tensile strength at break. The average of the three tests for the non-aged specimens shall be the basis for the percent volume change calculation.
3.3.3 Etastomer Components — Compression Set. Elastomer p.irts that tn.ay be exposed to fud g.i shall be made from materials having a compression set of no more than 25% after 22 hr at 21 2F (100CC). in specimens in accordance with ASTM 1)395, para. 5.2.
3.3.4 Polytetraftuoroethytene (PT!E) Materials.
19’FE materials shall comply with ASTM D4S94 or D4895.
3.4 Temperature Resistance
The materials used for valve bodies, plugs, bonnets, unions, and other external paris, excluding handles. shall have a solidus temperature in excess of 800°F (427°C). Seals and lubricants are exempt from this requirement.
3.5 Corrosion Resistance
3.5.1 Indoor Atmosphere. Those parts that are pro. vided with automatic compensation for wear shall be cormsion resistant with respect to indoor atmosphere (i.e., humidity and airborne cont.,rninants such as chloride and ammonia).
3.5.2 Salt Spray. Valves designated by the manufachirer for outdoor use shall meet the requirements of this paragraph. Valve ends shall be sealed with appropriate fittings. The valve shall then be exposed for % hr to a salt spray (fog) test as specified in ASTM BI 17. Salt spray (fog) testing temperature shall be maintained between 92°F and 97°F (33°C and 36°C). The saline soluhon shall consist of 5% sodium chloride and 95% distilled water by weight. Following the salt spray (fog) test, the valve shall be jm,xj from the chamber and examined with the wiaided eye. The valve shall not show signs of corrosion or other deterioration that affects the function of the valve. Following the salt spray test, the valve shall pass the leak tests specified in paras. 5.2.1 and 5.2.2 and shall open and close on application of a torque not to exceed that specified in Table 3.