An O-ring is a torus, or doughnut-shaped ring, generally molded from an elastomer. O-rings seal are used to prevent the loss of a fluid or gas. The seal assembly consists of an elastomer O-ring and a gland.
Advantages of O-ring:
◆ O-rings seal over a wide range of pressure, temperature and tolerance.
◆ In many cases an O-ring can be reused, an advantage over non-elastic flat seals and crush–type gaskets.
◆ No critical torque on tightening, therefore unlikely to cause structural damage.
◆They are cost-effective.