Double Acting Telescopic Cylinders

The extension and retraction fluid supply ports on double acting hydraulic telescopic cylinders are usually located at opposite ends of the cylinder assembly. This additional complexity makes double acting telescopic hydraulic cylinders very expensive. They are usually custom designed.To accomplish the double acting feature, additional hydraulic seals are added to internally seal off the individual stages. In addition, internal air or oil passageways are machined so that as each stage completes retracting, a passage is open to supply the next stage with pressurized fluid to retract.