The role of the O-ring in ORB port connections

Technical explanation

In an O-ring boss connection, known as ORB, the sealing geometry of the port and the fitting end work together. Parker's boss seal description shows that the O-ring cavity is defined separately from the thread. Therefore, a matching diameter and pitch alone do not prove a correct port match. The fact that the two ends of an adapter may be different connection types must be taken into account in the order description. For adjustable fittings, the positioning method is taken from the instructions for the product concerned; no general torque or number of turns is given here.

Source: S019, S103

Topic-specific checkpoints

Source: S019, S103

How is it assessed in practice?

Write the adapter order as end A and end B: family, size, male/female gender and sealing type should be stated separately for each end. Add damage at the port mouth and the condition of the O-ring to the inspection record. Do not leave the elbow loose contrary to the manufacturer's instructions in order to bring it to the desired angle. Match the seal material to the oil or other fluid. Determine the assembly torque from the size and material instructions for the product concerned, not from the name of the connection family.

Original editorial recommendation; not a clause of a standard.

Frequently asked questions

Are ORB and ORFS the same connection?

No. Both may have an O-ring, but the sealing surface and connection geometry are different.

Source: S019, S103