UL 1769-2016 pdf free download

UL 1769-2016 pdf free download.Cylinder Valves.
23.4 Oil Immersion test
23.4.1 Representative samples of each elastomeric material shall be immersed for 70 hours In IRM 903 oil. The samples and test fluid shall be at 70 ±3.6°F (21 ±2°C). The volume of the samples initially and at the conclusion of the immersion test shall be determined by the water displacement method and the percentage change and volume calculated. The material shall not show a volume change of more than 25 percent swelling or 1 percent shrinkage.
24 Low-Temperature Test
24.1 An elastomenc part shall not show any cracking or other damage after being subjected for 24 hours to air having a temperature of minus 40 ±2°F (minus 40 ±1°C) and then wrapped around a steel mandrel having a diameter of 0.25 inch (6.4 mm).
24.2 Three samples are to be subjected to this test. While still at the temperature of the cold chamber, each sample is to be bent around the mandrel until the segments of the sample touch. The operator is to wear gloves while handling the samples and the mandrel so as to reduce heat transfer to the samples.
24.3 With reference to the requirement in 24.1. when the elastomeric part does not comply with the requirements for visual examination, one complete valve assembly shall be placed in a cold chamber maintained at minus 40 ±2°F (minus 40 ±1°C) for a period of 24 hours. Immediately after the 24-hour exposure, the valve assembly is to be removed from the chamber and manually cycled for 25 cycles as described in 17.4 — 17.9, and then maintained at minus 40°F (minus 40°C) for 1 hour. The sample shall then immediately be subjected to the External Leakage Test. Section 15, and/or the Seat Leakage Test, Section 16, as appropriate. The test pressure for leakage test(s) of cylinder valves for use with LP•Gas shall be reduced to 50 psig.
25 Moist Ammonia Air Stress Cracking Test
25.1 After being subjected to the conditions described in 25.2 — 25.3. a pressure confining brass part containing more than 15 percent zinc shall:
a) Show no evidence of cracking, delamination, or degradation, or
b) Perform as intended when tested as described in 25.4.
25.2 One test sample of each size is to be subjected to the physical stresses normally imposed on or within a part as the result of assembly with other components. Samples with female tapered pipe threads, intended to be used for installing the product in the field, are to have the threads engaged and tightened to the torque specified in Table 14.1 Samples with female threads other than tapered pipe threads shall be torqued as specified by the manufacturer. Polytetrafluoroethylene (PTFE) tape or pipe compound is not to be used on any threads. Samples with male threads are evaluated in “as-received condition.UL 1769-2016 pdf free download.