O-Ring Face Seal

  • O-Ring Face Seal Hydraulic Fitting

O-Ring Face Seal (OFS) fittings were designed to eliminate leakage problems and still handle the greater pressure of today’s hydraulic systems, and are dimensionally standardized in SAE J1453. An OFS connection uses a Buna-N, 90 Durometer O-ring that seats into a grove in the face of the fitting. As the connection is tightened the O-ring compresses against a flat-face sleeve that is brazed onto the end of a tube, am makes a metal-to-metal seal crating a cavity that supports the O-ring. The sleeve also prevents twisting of the tube and supports it during the assembly process.


In addition, as the assembly is being tightened, a noticeable rise in torque is realized that deters over-torque abuse and avoids distortion. Therefore, the OFS design can be used multiple times buy just simply replacing the O-ring. Standard materials is steel with a RoHs compliant 96-hour salt spray finish that exceeds the SAE 72-hour salt spray requirement.