ASME B16.33 pdf free download

ASME B16.33 pdf free download MANUALLY OPERATED METALLIC GAS VALVES FOR USE IN GAS PIPING SYSTEMS UP TO 125 PSI (SIZES NPS 1 / 2 THROUGH NPS 2)
3 MATERIALS
3.1 Metallic Materials for Valve Parts Metallic materials known to be acceptable for compli- ance with this Standard are listed in Table 1. Other metallic materials may be used when the product incor- porating them meets the requirements of this Standard.
3.2 Lubricants, Sealants, and Seating Materials
3.2.1 Lubricants and Sealants. Lubricants and/ or sealants shall be resistant to the action of fuel gases such as natural, manufactured, and LP gases. The valve manufacturer is responsible for the selection of lubricants and sealants, and for the determination of their suitability for the service conditions specified in the scope of this Standard.
3.2.2 Seating and Stem Seal Materials. The valve manufacturer is responsible for selection ofseating and stem seal materials and for determination of their suitability for the service conditions specified in the scope of this Standard.
3.2.3 Elastomer Components
3.2.3.1 Air Aging Tests. Elastomer parts that are exposed to fuel gas shall be made from materials that, following 70 hr air aging in accordance with ASTM D 573 at 212°F (100°C), meet elongation, tensile, and hardness property requirements a follows: Tensile tests shall be conducted on six dumbbells in accordance with ASTM D 412. Three dumbbells shall be air aged 70 hr in accordance with ASTM D 573 at 212°F (100°C). The dumbbells shall have a thickness of 0.080 + 0.008 in. (2.0 ± 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 % retention calculation. Hardness tests shall be conducted using specimens in accordance with ASTM D 395, Type 2. Three specimens shall be air aged 70 hr in accordance with ASTM D 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 ±10 shore hardness points relative to the average hardness of the non-aged specimens.
3.2.3.2 Swell Tests. Elastomer parts, which are exposed to fuel gas, shall be made from materials that, after 70 hr exposure in n-hexane at 74°F (23°C), in accordance with ASTM D 471, meet the volume change, elongation, and tensile property requirements as follows: Volume change test shall be conducted using six specimen in accordance with ASTM D 471, Section 8. Three specimen shall be exposed for 70 hr at 74°F (23°C) in n-hexane in accordance with ASTM D 471. The average of the three individual n-hexane 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 specimen shall be the basis for the % retention change calculation. Tensile tests shall be conducted on six dumbbells in accordance with ASTM D 412. Three of the tensile tests shall be conducted on dumbbells exposed in n- hexane at 74°F (23°C) for 70 hr in accordance with ASTM D 471. The dumbbells shall have a thickness of 0.080 + 0.008 in. (2.0 ± 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 specimen shall be the basis for the % volume change calculation. 3.2.3.3 Compression Set Tests. Elastomer parts, which 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 D 395, Method b, using standard test specimen in accordance with ASTM D 395 (See para. 5.2). 3.2.4 PTFE Components. Polytetrafluoroethylene (PTFE) materials shall comply with ASTM D 4894 or ASTM D 4895.ASME B16.33 pdf free download