stem seal on valves

例句：

1. 1. Thenew valve design uses a stem seal toprevent leaks.
   新的阀门设计使用了阀座密封来防止泄漏。
2. 2. The valvewas replaced with a stemseal to improve performance.
   阀门被替换为一个阀座密封以提高性能。
3. 3.The stem seal on the valve is crucialfor maintaining proper pressure levels.
   阀门上的阀座密封对于保持适当的压力水平至关重要。