Product Detail

JST's back up ring compensate for large temperature fluctuations. Using Back-up Rings allows O-Rings to be utilized in higher pressure applications, where larger extrusion gaps are required and where there are reciprocating or rotating movements. 

Back-up Rings are protective and supporting elements with no sealing function. 

The back up ring material could be  PEEK, modified PTFE. PEEK™ back-up rings are designed to prevent extrusion in elastomer O-ring sealing systems.

JST makes custom and standard PEEK back-up rings.

Custom sizes up to 24” outer diameter.

Elastomer O-rings serve as effective seals for dynamic and static applications in hydraulic and pneumatic equipment systems. A drawback of elastomer O-rings is their tendency to extrude into the clearance of mating surfaces with increasing pressures and temperatures. Higher temperatures impose a severe burden on the physical and mechanical properties of elastomer O-rings, which further increases their tendency to extrude. The combination of high pressures and high temperatures is a common occurrence in fluid systems. This establishes the need for the back-up ring in preventing O-Ring extrusion.

JST makes various types of PEEK™ back-up ring designs.

PEEK back-up rings material

Virgin PEEK™

• Engineered thermoplastic.
• PEEK™ can be used up to 480°F.
• Excellent chemical resistance.
• Very low moisture absorption.
• Good wear and abrasion resistance.

Glass filled PEEK™

• PEEK™ with the addition of glass fibers.
• Glass fibers reduce the expansion rate and increase the flexural modulus.