Back UP Ring 67411-007

Back-up Ring for an Embraer Aircraft for added security when sealing the piston inside a pneumatic cylinder. A soft and flexible material (O-Ring) is required to prevent leakage, but those same properties may leave the seal material vulnerable to being pulled out of its seat and then pinched or torn in the narrow space between piston and cylinder wall. If the joint cannot be redesigned, or a more resistant elastomer used, then the solution may be direct reinforcement with a stiffer material - in the form of a hard inner ring (Back Up Ring) in this case.