Replacing a hydraulic system on a piece of used equipment, or selecting the right size of cylinder for a new system or application needs to be done with attention to several different factors. Unfortunately, unless the current cylinder is the one installed by the OEM, it is a good idea to complete measurements and to avoid falling into the trap of simply replacing the current cylinder with the same model and size.
It is not uncommon for replacement cylinders to be incorrectly selected or equipment. A good sign of this type of problem is the need for increased maintenance, repairs, or replacement of the single acting hydraulic cylinder.
Cylinder Type
There are two basic types of cylinders used in general types of applications. This includes a tie rod and a welded cylinder. Tie rod cylinders have rods on four or more locations around the cylinder, with the rods holding the end caps in place.
Welded cylinders have the caps welded in place, and do not use tie rods. This allows for a more streamlined cylinder that is ideal for installation in smaller physical spaces without any loss of lifting or pushing ability.
Single or Double Acting
A single acting hydraulic cylinder has one hose and port, and the hydraulic pressure is used to extend the rod, with retraction occurring with pressure reduction and the weight of the equipment. With a double acting cylinder, hydraulic pressure from two ports in the cylinder is used to move the rod to extend and retract.
Other Considerations
Sizing and choice of a single acting hydraulic cylinder must be based on the desired stroke length (the lift or push capacity), as well as the mounting option on the equipment. The peak load amount, the rod diameter to support the maximum load, as well as the maximum pressure in the hydraulic system all need to be carefully considered when choosing any hydraulic cylinder.
