manual shutoff valve

例句：

1. 1.The manual shutoff valve is used to prevent the leakage of oil.
   手动切断阀用于防止油泄漏。
2. 2. The manual shutoff valve is an important safety device in the process control system.
   手动切断阀是过程控制系统中的重要安全装置。
3. 3. The manual shutoff valve can be manually operated by the operator.
   手动切断阀可以由操作员手动操作。