Oring boxes are used for different types of heavy machineries like HITACHI, KOBELCO , DOASAN , CATERPILLAR , HYUNDAI, VOLVO  like that many other earth moving machineries

An O-ring is a torus, or doughnut-shaped ring, generally molded from an elastomer, although O-rings are also made from PTFE and other thermoplastic materials, as well as metals, both hollow and solid. This handbook, however, deals entirely with elastomeric O-rings.

They seal over a wide range of pressure, temperature and tolerance.

• Ease of service, no smearing or retightening.

• No critical torque on tightening, therefore unlikely to cause structural damage.

• O-rings normally require very little room and are light in weight.

• In many cases an O-ring can be reused, an advantage over non-elastic flat seals and crush-type gaskets.

• The duration of life in the correct application corresponds to the normal aging period of the O-ring material.

• O-ring failure is normally gradual and easily identified.

• Where differing amounts of compression effect the seal function (as with flat gaskets), an O-ring is not effected because metal to metal contact is generally allowed for.

• They are cost-effective.