Pilot check valves are used to block the cylinder in both directions. Flow is free in one direction and blocked in the reverse direction until pilot pressure is applied. Face mounting enables assembly directly onto the cylinder.

VBPDE FL先导式液压锁用于在进油、回油两个方向上锁住油缸。当先导油液没有施加在对侧方向的回路时，油液正向自由流动，反向截至，即为单向阀功能。当先导油液施加在对侧回路时，则正向、反向均可流动。板式安装的方式可以更佳方便的安装在油缸上。（需要做底板）