expansion valve gear

例句：

1. 1.The expansion valve is responsible for controlling the flow of gases in the engine.
   膨胀阀负责控制发动机中气体的流量。
2. 2. The expansion valve was replaced due to its failure to function properly.
   由于膨胀阀无法正常工作，所以被更换了。
3. 3.The expansion valve is an essential component of the air conditioning system.
   膨胀阀是空调系统的一个关键部件。