在套缸升降机发生事故时反应速度要求快、油路封闭可靠无内泄漏，所以采取液控单向阀的形式。
When stationary lift accident requires fast reaction speed, oil enclosed within a reliable leak-free, so take the form of pilot operated check valve.
套缸升降机伸缩系统中，在发生事故时，除满足立即自动锁闭油路之外，然后还必须通过人工操作阀门使油缸回缩使在工作台上的人员和设备下来。
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.
