What Are O-ring Face Seal Fittings?

- Disadvantage of using ORFS fittings:
- Advantages of using ORFS fittings:

O-ring Face Seal(ORFS) fittings incorporate an O-ring at the face of the fitting and are designed to eliminate leaks in high pressure hydraulic systems. Made to SAE J1453 standard, ORFS connections typically use Buna-N or Viton, 90 Durometer O-rings that seat into a grove in the face of the fitting. These elastomeric seals provide a leak-proof, drop-in replacement for SAE 37° flared tube fittings, literally eliminating hydraulic leaks when used properly. When the connection is tightened the O-ring compresses against a flat face sleeve, which has been brazed onto the end of a tube. This makes a metal-to-metal seal with a leak barrier provided by the O-ring. The flat face sleeve also eliminates twisting of the tube and provides support during assembly.

O-ring face seal fittings can eliminate leaks in hydraulic systems at operating pressures as high as 6,000 PSI. They are designed specifically for applications where elastomeric seals are acceptable to overcome leakage and variations in assembly procedures. The fittings can be easily connected to a range of tubing grades by silver brazing. In addition, ORFS fittings can be disassembled and reassembled in the field to facilitate replacement of the O-ring or the entire assembly.

Disadvantage of using ORFS fittings:

The relevant temperature rating is limited by the o-ring seal material making these fittings ineffective in high temperature applications.

Advantages of using ORFS fittings:

They’re readily available and offer a large variety of sizes shapes, combinations and materials.

Can eliminate leaks in hydraulic systems with high operating pressures.

These elastomeric seals provide a leak-proof, drop-in replacement for SAE 37° flared tube fittings, literally eliminating hydraulic leaks when used properly.

Used in the majority of applications where there are high pressures that are subject to flexing or pressure surges and they are also the preferred connection in high vibration systems because the soft O-ring seal absorbs shock better than any metal-to-metal sealed fittings.

Can be easily connected to a range of tubing grades by silver brazing or forming.

The nature of ORFS fittings resists complications associated with over-assembly as they can be over torqued by as much as 200%.

The flat face connection design coupled with the repeatability of the o-ring, makes these fittings reusable and easily maintainable in the field.

O-ring face seal fittings are often the best or sometimes only practical choice and care needs to be taken to properly identify the right connection to create a safe and leak resistant seal.