ISO 28921-2:2015规定了低温应用中隔离阀的型式试验要求，以验证阀门在低温下的性能？50摄氏度到？196摄氏度。 注:ISO 28921-1涵盖了公称尺寸（DN）、公称管道尺寸（NPS）、公称压力（PN）和等级。 ISO 28921-2:2015不评估阀门执行机构，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致动器。如果致动器直接安装在试验台上方，且冷气体吞没致动器，则应特别考虑试验期间冷气体蒸汽的影响。 ISO 28921-2:2015不适用于根据ISO 21011设计的用于低温容器的低温阀门。

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.