ASME B16.44-2012 pdf free

ASME B16.44-2012 pdf free.Manually Operated Metallic Gas Valves for Use in Aboveground Piping Systems Upto5psi.
3.3 Seating and Stem Seal Materials
3.3.1 Elastomer Components — Air Aging. Elastomer parts that are exposed to fuel gas shall be made from materials that, following 70-hr air aging in accordance with ASTM 0573 at 212°F (100°C), meet the elongation, tensile and hardness property requirements of paras. 3.3.11 and 3.3.1.2.
3.3.1.1 Tensile tests shall be conducted on six dumbbells in accordance with ASTM 0412. Three dumbbells shall be air aged 70 hr in accordance with ASTM 0573 at 212°F (100°C). 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 tests for the aged dumbbells shall exceed 60% retention of ultimate elongation and 60% 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 calculation.
3.3.1.2 I lardness 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 2129: (100°C). The average of the three individual tests for the aged specimens shall not show a hardness change of more than ± 10 Shore hardness points relative to the average hardness of the non-aged specimens.
3.3.2 Elastomer Components — Swell Test. Elastomer parts that are exposed to fuel gas shall be made from materials that, after 70-hr exposure in n-hexane at 73°F (23°C) in accordance with ASTM 0471, meet the volume change, elongation, and tensile property requirements of paras. 3.3.2. 1 and 3.3.2.2.
3.3.2.1 Volume change tests shall be conducted using six specimens in accordance with ASTM D471, Section 8. Three specimens shall be exposed for 70 hr at 73°F (23°C) in n-hexane in accordance with ASTM D471. The average of the three individual n-hcxane tests shall not show an increase in volume of more than 25% or a decrease in volume of more than 1%. The average of the three tests for the non-aged specimens shall he the basis for the percent retention change calculation.
3.3.2.2 Tensile tests shall be conducted on six dumbbells in accordance with ASTN4 1)412, Three of the tensile tests shall be conducted on dumbbells exposed in n-hexane at 73°F (23°C) for 7() hr in accordance with ASTM 1)471. 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 Elastomer Components — Compression Set. 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 specimens in accordance with ASTM D395, para. 5.2.
3.3.4 Polytetraftuoroethytene (PTFE) Materials.
PTFE materials shall comply with ASTM D4894 or [34895.
3.4 Temperature Resistance
The materials used for valve bodies, plugs, bonnets, unions, and other external parts, 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 provided with automatic compensation for wear shall be corrosion resistant with respect to indoor atmosphere (i.e., humidity and airborne contaminants such as chloride and ammonia).ASME B16.44 pdf download.