Ring Back-Up – RA1077665

Back-up rings sit behind an O-ring in a hydraulic gland to keep the seal from extruding into the clearance gap under high pressure, and this Raymond ring does that job in the cylinder or fitting it was cataloged for. When system pressure spikes, an unsupported O-ring can creep into the gap between the piston and bore and tear; the back-up ring fills that gap and holds the seal in place, extending seal life on a working hydraulic circuit.

As a hardware-level part of the seal stack, it is replaced whenever the mating O-ring or seal is serviced, since a fresh seal running against a nicked or worn back-up ring gives up the same protection it was meant to add. Match the ring to the bore and groove it seats in, since back-up rings are sized to the specific seal they support.