Pentaflow lift cylinders are unique. In the base of the cylinder piston there is a port. This port is sealed by a ball to prevent oil from passing through. When oil is pumped into the cylinder, the cylinder extends. When the cylinder is at full extension, an actuator pushes the ball off the port which allows oil to return to the reservoir. This prevents the cylinder from dead ending. This also helps bleed any air inside of the hydraulic system. When the cylinder retracts, it siphons hydraulic oil into the top of the cylinder keeping all components of the cylinder lubricated.
Contact a Pentalift Sales Representative for more information.