Hollow plunger cylinders - spring return
Hollow plunger cylinders with spring return for the hydraulic pushing and pulling of heavy loads. These hollow plunger cylinders (also known as jacks, bottle jacks, presses, bottles or pumps) have been especially developed for pulling using pulling rods. Almost all hydraulic cylinders are provided with a hollow saddle, to protect the plunger from damage while a pulling rod is being pulled through the plunger. The HHJ 5 S 2.5, HHJ 12 S 5 and HHJ 12 S 15 do not have a saddle.
Hollow plunger cylinders - hydraulic return
Hollow plunger cylinders with hydraulic return are provided with a High Flow female coupler A 118 on the inlet port, a High Flow female coupler with a pressure relief valve A418 on the outlet port and a hollow saddle to prevent damage to the plunger while a pulling rod is being pulled through it.
Hollow plunger cylinder - gravity return
Holmatro offers one hollow plunger cylinder model with gravity return: the HHJ 30 G 5. This compact single-acting cylinder has a capacity of 30 tons, a stroke length of 50 mm and a closed height of 120 mm.
Hollow plunger cylinders are suitable for many applications, including pressing flanges, toothed sprockets, etc. onto axles using a pulling rod, the testing of glued or mechanical anchoring and the tensioning of rods, wires, etc. for pre-stressed concrete structures. The cylinders are also used whilst moving loads using a pulling rod. Hollow plunger cylinders are suitable for the removal of the axle on chain sprockets or toothed sprockets. They are used during the dismantling and re-pressing of bearing bushes, rods, cylinder linings, etc. and to pull pipes out of heat exchangers.