clack valve

1. In addition, because of immaturity of the existing opening criterion ( a criterion to judge if the valve clack is open) and the shortage of the use experience, safety valve on-line test devices are not broadly applied.
   此外，现有安全阀在线校验仪在判开准则和使用性等方面还存在不成熟的地方，因此还未获得广泛应用。

noun

1. a simple valve with a hinge on one side

   Synonym:    clackclapper valve