Back-up rings are also known as anti-extrusion rings since their main function is to prevent o-rings from entering the clearance gaps due to internal pressure. They avoid the seal from experiencing premature failure. 

Backup rings are not seals themselves, but are used in conjunction with O-rings or other seals in high-pressure applications. Backup rings are installed in the downstream side of the gland, however, can be installed either side of the O-ring to give a high-performance double-acting seal.

Back-up rings come in a variety of materials such as: PTFE, filled PTFE, PEEK.

Types of Back-up Rings

• • Solid Rings
  • Split Rings
  • Spiral Wound

PTFE Back-up Rings Advantages & Application
When used for relevant purposes under appropriate conditions, industrial PTFE backup rings provide various applicable benefits. PTFE backup rings are built in such a way that they can be used to prevent extrusion in rubber sealing systems.