在套缸升降機發生事故時反應速度要求快、油路封閉可靠無內泄漏，所以采取液控單向閥的形式。
When stationary lift accident requires fast reaction speed, oil enclosed within a reliable leak-free, so take the form of pilot operated check valve.
套缸升降機伸縮系統中，在發生事故時，除滿足立即自動鎖閉油路之外，然后還必須通過人工操作閥門使油缸回縮使在工作臺上的人員和設備下來。
In the fixed lift telescopic system, in the event of an accident, in addition to meet immediately and automatically locking the oil addition, then you must make the cylinder retraction on the table so that personnel and equipment down manually operated valves.
