valve grinding

例句：

1. 1. The engineers are busy grinding the valves for the new machine.
   工程师们忙于为新机器研磨阀门。
2. 2. The valve grinding process is crucial for ensuring the proper function of the system.
   阀门研磨过程对于确保系统正常运行至关重要。
3. 3. During the maintenance, the valve grinding tools were used to remove any debris from the valves.
   在维护过程中，使用阀门研磨工具来清除阀门上的任何杂物。