O-Rings are used to keep fluid or air in or out of a defined space. O-Ring is used to block a pathway that fluid or air may escape through. These rings are commonly used in mechanical applications, such as pipe connections, and help to ensure a tight seal between two objects. O-Rings are designed to be seated in a groove or housing that keeps the ring in place. Once in its track, the ring is compressed between the two pieces and, in turn, creates a strong seal where they meet.

Advantages of using an O-Ring

  •  No critical torque on tightening, therefore unlikely to cause structural damage.
  •  O-Rings normally require very little room and are light in weight.
  •  The duration of life in the correct application corresponds to the normal aging period of the O-Ring
  •  They seal over a wide range of pressure, temperature and tolerance.
  •  Where differing amounts of compression effect the seal function (as with flat gaskets), an O-Ring is not affected because metal to metal contact is generally allowed for.
  •  In many cases an O-Ring can be reused, an advantage over non-elastic flat seals and crush-type

In a truly static seal, the mating gland parts are not subject to relative movement, except for small thermal expansion or separation by fluid pressure. Its uses are seal under a bolt head or rivet, a seal at a pipe or tubing connection, a seal under a cover plate, plug or similar arrangement or, in general, In a rotary seal, either the inner or outer member of the sealing elements turns around the shaft axis in one direction only. Uses of rotatory seals include sealing a motor or engine shaft, or a wheel on a A pneumatic seal may be any of the previously described types of O-Ring seals but is given a different classification because of the use of a gas or vapour rather than a liquid. This has a vital effect on the lubrication of the O-Ring and thus influences all moving (or dynamic) seal installations. A further point is that pneumatic seals may be affected by the increase in gas temperature with compression. A vacuum seal confines or contains a vacuum environment or chamber. The leakage tolerance is less than for pressure seals.

Multiple O-Rings

They are useful in a vacuum seal to reduce permeation. In a seat seal, the O-Ring serves to close a flow passage as one of the contact members. Examples of a seat-seal include O-Ring as a “washer” on the face of a spiral threaded valve, a seal on the cone of a floating check valve, and a seal on the end of a solenoid plunger.

In an oscillating seal, the inner or outer member of the seal assembly moves in an arc (around the shaft axis) relative to the other member. This motion tends to rotate one or the other member in relation to the O-Ring. An example of an oscillating seal is an O-Ring seal for a faucet valve stem.

These are the specific uses of various different kinds of O-Rings.