Back up Rings are manufactured in a variety of styles including, SOLID, SPIRAL, CONTOURED, BUTT SPLIT AND SCARF SPLIT. Their purpose is to prevent the O Ring from entering the clearance void in the machine if pressure is extensive on the O Ring, causing possible premature failure.

A Seal Plastics are manufacturers of various sizes of metric and imperial Back up Rings and can produce them in a number of materials: VIRGIN PTFE, GLASS FILLED PTFE, BRONZE FILLED PTFE, CARBON FILLED PTFE, NYLON, ACETAL, GLASS FILLED NYLON, PHENOLIC, PEEK, GLASS FILLED PEEK AND EKINOL.