O-rings are the most commonly used seals in fluid-power systems. However, elastomeric O-rings are unlike most of the materials that O-rings must deform to function properly. sizing o-rings to the correct size, and the housing that accommodates them with the right interference fit, or groove depth will determine the pressure capability of the o-ring. The use of back-up rings will also extend the extrusion resistance strength of the o-ring.

O-rings are installed in cavities known as glands and then compressed. The resulting zero clearance within the gland provides the seal that blocks the flow of liquids and gases. This simple arrangement serves many fluid-power systems very well, but success still requires careful design, material selection and installation procedures.

O-Rings are made using a wide variety of materials including Viton, FKM, FFKM, Aflas, EPDM, Silicon, Nitirle, Buna-N ,FVMQ and other materials. They are Designed to stop leakage when fluids are transferred, o-rings may be in place along rotating shafts, sleeves, placed in flange grooves, valve bonnets, or any threaded or bolted connection. O-rings are an important accessory in every industrial and residential purpose.