Backup rings are anti-extrusion devices that are used in dynamic and static sealing to prevent the migration of sealing material into the extrusion gap under system pressure. They are designed to fit between the O-Ring and the extrusion gap and prevent the extrusion of the O-Ring. Backup rings are installed with O-Rings and quad rings / X-Rings to prevent gap extrusion in applications above 5 MPa / 725 psi, it is sometimes called a o ring backup ring or backup o ring. They come in different geometries and materials to suit every seal type and application
Meridian offers many different high quality Backup Rings and other Seals for all types of environments and sealing applications. The materials include, but are not limited to, PTFE / teflon backup ring, PEEK, PPS. The material of choice for rubber contoured rings usually is 90 durometer nitrile.
CONTOURED BACKUP RINGS
Contoured backup rings were developed primarily for service in petroleum based hydraulic fluids, at -4°C to 121°C (-40°F to 250°F). The standard 90 durometer nitrile product, provides the maximum benefits in backup ring service. Compounds for use in other fluids and for temperatures up to 204°C (400°F) are available.
Contoured backup rings will stretch up to 50%, and are quickly and easily installed. Advantages of the contour design are obtained regardless of how the contoured rings are installed – they may be installed with the concave face in either direction, toward or away from the o-ring.
