Backup rings can be made from a variety of materials, including polymers. In this article, we will look at PTFE and PEEK backup rings while at the same time reviewing some of the basics of backup rings.
Why Use Backup Rings?
Rubber o-rings are good, but when temperatures and pressures rise they have a bad habit of extruding into clearance between mating surfaces, which isnt a good thing. In fact, extrusion failure is one of the main causes of o-ring failure. As the o-ring begins to extrude into the clearance gap, it will experience more and more damage until it is useless. This phenomenon is sometimes called nibbling, and when it occurs you will notice that the o-ring will have a ragged edge on the low-pressure side.