Back up ring for Lorain 445

The back up ring, identified by part number 1218-151, serves as a support component in hydraulic and pneumatic systems. It is designed to prevent the extrusion of O-rings or lip seals when subjected to high operating pressures. By providing structural support, the ring helps the primary seal maintain its shape and sealing capacity within the housing, which prevents fluid leakage and ensures the system operates at the required pressure levels.

This component is specifically designed for the Lorain 445 crane. In these machines, back up rings are utilized within hydraulic cylinders, control valves, and other assemblies responsible for boom movement, slewing, and outrigger deployment. Proper installation of this ring is necessary to protect the primary seal from deformation during high-pressure cycles.

Back up rings function by filling the clearance gap between mating parts in a hydraulic assembly. When pressure is applied, the O-ring tends to deform into the gap; the back up ring acts as a rigid barrier that stops this extrusion. Utilizing the correct back up ring is a standard maintenance practice to ensure that seals remain effective and to avoid the premature failure of hydraulic components.