The Back-up Ring

What is a Back-up Ring?

It is a ring manufactured from a variety of relatively hard materials, which when placed in a seal groove between the O-ring and the clearance gap i.e. on the seal’s low-pressure side, acts as a support for the O-ring.

Function of a Back-up Ring 

back-up-ringThe back-up ring blocks the gap into which the pressurized O-ring might otherwise extrude in both static and dynamic applications. The back-up ring also reduces friction and wear by trapping lubricant around the seal.

Note: The use of the harder 90-durometer O-rings are used to better resist extrusion. Friction and wear normally increases with this harder material. In many cases a longer lasting solution may be the use of a 70-durometer with a 90-durometer back-up.

Good Advice: It is wise to use two back-ups, one on either side of the O-ring, even if pressure is from one side only, as this eliminates the possibility of installing a single back-up on the wrong side of the O-ring.

Tests have proved conclusively that using a back-up has clear advantages.

It is imperative to use the correct shore hardness, type of material, and more. A quick call to an expert can save many hours of frustration and a waste of money. Furthermore, should you be experiencing any leakage problems contact FUZION TRADING