UL 252A-2019 pdf free download

UL 252A-2019 pdf free download.Compressed Gas Regulator Accessories.
13.3.1 The test is to be conducted at outside air temperatures within the range of minus 30CC to 40°C (minus 22° F to 104°F). The volume of each of three specimens is to be determined by weighing as described in 13.2.1, except that (M2) isto be obtained by weighing in ethyl alcoho’ instead of water.
13.3.2 After weighing, the specimens are to be wiped dry and placed in a closed chamber having its inlet connected to a cylinder of MPS With the discharge valve fron, the chamber open. liquid MPS is to be allowed to flow through the chamber until the air is displaced. The discharge valve is then to be closed. With the inlet connection to the cylinder open, exposure is to continue for 70 hours.
13.3.3 The specimens are then to be removed from the chamber and immediately placed in a stoppered flask. The specimens are to be individually removed and weighed in air (M3). The weight is to be obtained within 30 seconds after removal from the flask. The final weight in ethyl alcohol CM4) is to be determined immediately thereafter.
13.3.4 The specimens are then to be conditioned in air at a temperature of 23 ±2°C (73 plus 4” F, minus
3°F) for 70 hours and weighed This final weight is to be used for calculating the weight loss.
13.3.5 The volume change and weight loss values are to be calculated as described in 13.2.3 and
13.2.4.
14 Accelerated Aging Test for Elastomers
14.1 A part made of an elastomer which is exposed to oxygen during intended use shall not crack nor show visible evidence of deterioration following exposure for 96 hours to oxygen at a pressure of 300 ±10 psig (2.07 ±0.07 MPa) and at a temperature of 70.0 ±1.0°C (158.0 ±1.8°F) when tested in accordance with the Standard Test Method for Rubber-Deterioration by Heat and Oxygen, ASTM D572.
14.2 An elastomer part not exposed to oxygen during intended use is to be subjected to an accelerated air oven aging test. The elastomers are to be exposed for 70 hours at 100°C (212°F) in a Type lIA oven as specified in the Standard Specification for Gravity-Convection and Forced-Ventilation Ovens. ASTM E145.
Exception: Elastoiner parts exposed to oxygen as specified in 14_i are not required to be subjected to this test
15 Comparative Corrosion Test
15.1 General
15.1.1 When subjected to comparative corrosion tests as described in 15.1.2 — 15.4.2. a protective coating shall provide protection against corrosion at least equivalent to that provided by the zinc coatings specified in 6.5.UL 252A-2019 pdf free download.