Backup Rings

Parbak® style backup ring with a curved cross-section.

This style of backup ring is contoured on one face to minimize distortion of the o-ring when under pressure. Parbak® style backup rings should be installed with the contoured face against the o-ring, but reversal does no harm.

90A Durometer | Buna-N Rubber Material | 2 5/8 in Nominal Inner Diameter | 1/8 in Cross Section | Backup Ring

Parbak® style backup ring with a curved cross-section.

This style of backup ring is contoured on one face to minimize distortion of the o-ring when under pressure. Parbak® style backup rings should be installed with the contoured face against the o-ring, but reversal does no harm.

90A Durometer | Buna-N Rubber Material | 6 1/2 in Nominal Inner Diameter | 1/4 in Cross Section | Backup Ring

Solid Urethane backup ring with a flat cross-section.

95A Durometer | Urethane Material | 4 1/8 in Nominal Inner Diameter | 3/16 in Cross Section | Backup Ring

Hytrel backup ring with a flat cross-section.

Molded of 55D Durometer Hytrel, these back-up rings provide excellent extrusion resistance and tolerance to fluids such as phosphate esters, hydraulic oil and water. Stretched for installation, they return quickly to their original size for easy installation.

55D Durometer | Hytrel Material | 4 5/8 in Nominal Inner Diameter | 3/16 in Cross Section | Backup Ring

Parbak® style backup ring with a curved cross-section.

This style of backup ring is contoured on one face to minimize distortion of the o-ring when under pressure. Parbak® style backup rings should be installed with the contoured face against the o-ring, but reversal does no harm.

90A Durometer | Buna-N Rubber Material | 2 1/2 in Nominal Inner Diameter | 1/8 in Cross Section | Backup Ring

Parbak® style backup ring with a curved cross-section.

This style of backup ring is contoured on one face to minimize distortion of the o-ring when under pressure. Parbak® style backup rings should be installed with the contoured face against the o-ring, but reversal does no harm.

90A Durometer | Buna-N Rubber Material | 4 3/4 in Nominal Inner Diameter | 1/8 in Cross Section | Backup Ring

Hytrel backup ring with a flat cross-section.

Molded of 55D Durometer Hytrel, these back-up rings provide excellent extrusion resistance and tolerance to fluids such as phosphate esters, hydraulic oil and water. Stretched for installation, they return quickly to their original size for easy installation.

55D Durometer | Hytrel Material | 3 3/4 in Nominal Inner Diameter | 0.11 in Cross Section | Backup Ring

Solid Urethane backup ring with a flat cross-section.

95A Durometer | Urethane Material | 3 1/8 in Nominal Inner Diameter | 3/16 in Cross Section | Backup Ring

Solid Teflon backup ring with a flat cross-section.

PTFE can withstand high temperatures and is compatible with nearly all fluids.

PTFE Material | 11 1/2 in Nominal Inner Diameter | 1/4 in Cross Section | Backup Ring

Style 590 Back-up Rings feature exceptional strength and abrasion resistance along with a 53 Shore D hardness rating which makes them suitable for high pressure service where extrusion is a problem. Primarily used as a u-seal back-up, these rings can be used with o-rings. They also retrofit urethane and PTFE back-up rings, with greater performance characteristics. “S” suffix designates a split ring.

53 Shore D Durometer | Hytrel Material | 4 in Nominal Inner Diameter | 1/4 in Cross Section | Backup Ring