标准摘要
[中文适用范围]： ISO 28921 的这一部分规定了低温应用隔离阀型式试验的要求，以验证阀门在 – 50 °C 至 – 196 °C 的低温下的性能。 注：标称尺寸 (DN)、标称管道尺寸 (NPS)、标称压力 (PN) 和等级包含在 ISO 28921 的本部分中，不评估阀门执行器，除非它们是阀门的组成部分。 测试期间的阀门可以手动操作，也可以在测试期间使用执行器。 特别是如果执行器直接安装在测试台上方并且冷气体吞没执行器，则应考虑测试期间冷气体蒸汽的影响。 ISO 28921 的本部分不适用于低温服务的阀门，其设计符合 [外文原描述]： ISO 28921-2:2015 specifies requirements for the type testing of isolating valves for low-temperature applications to verify the performance of valves at a low temperature from ? 50 °C down to ? 196 °C. NOTE Nominal sizes (DN), nominal pipe sizes (NPS), nominal pressure (PN) and Classes are covered in ISO 28921‑1. ISO 28921-2:2015 does not evaluate valve actuators unless they are integral part of the valve. Valves during testing can be operated manually or an actuator can be used during the testing. The effect of cold gas vapours during testing is taken into consideration in particular if the actuator is mounted directly over the test stand with the cold gases engulfing the actuator. ISO 28921-2:2015 does not apply to valves for cryogenic services, designed in accordance with ISO 21011, used with cryogenic vessels.
英文名称Industrial valves — Isolating valves for low-temperature applications — Part 2: Type testing