Anti-extrusion rings or Back-Up Rings are used to prevent extrusion of a primary seal in high pressure applications.
Back-up Rings do not provide any sealing function.
They are simply intended to reduce the extrusion gap and prevent the O-Ring or seal extruding causing seal failure.
ANTI-EXTRUSION PROFILES
Contoured backup rings were developed primarily for service in petroleum based hydraulic fluids.
For Inch and Metric O-rings
Available solid or split NBR or FKM supplied solid can be split if required
Split backups are manufactured the same as solid backups, but have an angled cut in one location to allow installation in solid pocket grooves. Split is preferred for materials like PEEK, and Nylons
Solid back-ups are used when installation is not an issue, that is, when a groove other than a solid pocket O-Ring groove is available. In some instances solid backups can be stretched into the grooves depending on the material and size.
Spiral design adjusts to bridge the extrusion gap and applications with large temperature changes and tolerances. Easy installation in closed grooves for external sealing applications
For standard inch O-ring grooves only **PTFE ONLY**
Rectangular back-up rings are used for moderate temperatures and high pressures.
Rectangular back-up rings are used for moderate temperatures and high pressures.
Keystone shape back-up rings used with the primary seal for piston and rod special applications to provide better stability.
Wedge shaped back-up rings designed to slide along their common angles as the pressure increases to eliminate extrusion under high pressures.
The triangular back up are integrated into the seal and are positively actuated. System pressure forces the back-up ring
Towards the extrusion gap.
For Spring-energized Seals Only
Custom back-ups lip seals