UL 79-2021 pdf free download.Power-Operated Pumps for Petroleum Dispensing Products. 5.2 With reference to the requirement in 5.1, an elastomeric part used in contact with liquid or vapor shall have the following properties when tested as specified in the Standard for Gaskets and Seals. UL 157: a) Those properties relating to minimum tensile strength and elongation after oven aging, as specified in UL 157. The service temperature used to determine the conditioning time and temperature for oven aging is to be 140°F (60°C), unless the product is designated for use at a higher temperature, or the temperature of the component measured during the temperature test is higher. b) Low temperature rating of minus 20°F (minus 29°C). C) Volume change and extraction as specified in the requirements for UL 157, for end-use applications of gasoline, gasoline/alcohol blends up to 15% Ethanol, gasoline/alcohol blends up to 15% Methanol, diesel fuel, fuel oil, and lubricating oil. Other end-use applications, when marked on the pump, shall use the fluids marked for exposure. Exception No. 1: Polytetrafluoroethylene (PTFE) is considered to comply with the requirements of this paragraph. Exception No. 2: When an elastomenc par? does not comply with the requirements described in (a) — (c). the pump assembly shall be evaluated in accordance with 5.5. Exception No. 3: Testing with methanol is only required when the product is specifically rated for methanol blend use. 5.3 An elastomeric part forming a part that is depended on for protection of electrical components from rain or submersion in water shall have the following physical properties when tested as specified in the Standard for Gaskets and Seals, UL 157: a) Those properties relating to minimum tensile strength and elongation after oven aging, as specified in UL 157. The service temperature used to determine the conditioning time and temperature for oven aging is to be 140F (60°C), unless the product is designated for use at a higher temperature, or the temperature of the component measured during the temperature test is higher. b) Low temperature rating of minus 20°F (minus 29°C). 5.4 The Standard for Gaskets and Seals. UL 157, provides for the testing of either finished elastomenc parts, or sheet or slab material. Sheet or slab material is to be tested when the elastomeric parts are 0- nngs having a diameter of less than 1 inch (25.4 mm). The material tested is to be the same as that used...
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