working valve

例句：

1. 1. The engineer carefully inspected the working valve of the machine before starting it.
   工程师在启动机器前仔细检查了机器的工作阀。
2. 2. The working valve was designed to prevent leaks during operation.
   这个工作阀的设计是为了在运行过程中防止泄漏。
3. 3. The technician replaced the worn-out working valve with a new one.
   技术员用一个新的工作阀替换了磨损的阀门。