The O-ring seal is the most simple and cheapest seal. It is largely used in static sealing, but not in dynamic sealing because of its short operating life, often insufficient.
O-rings can be made of a great variety of elastomers; this gives the seal a high compatibility with a wide range of fluids and temperature.
Besides the standard NBR compounding (acrylonite-butadiene) with a nominal hardness of 70° and 90° ShA, O-rings are available also in:
Fluoroelastomer 70°ShA
Siliconelastomer 75°ShA
Ethylene-propylene elastomer  70°ShA
Polyurethane 93°ShA

Because of their materials and profile O-ring seals are not much extrusion-resistant comparing with other sealing systems.
When the ratio between operating pressure and clearance gap between the metal parts is unfavourable, an antiextrusion ring is needed to protect the O-ring.
We produce:
- polyester rings (TPE-55) both for O-ring of SAE series (AP) and metric O-rings (AM)
- nitrile rubber rings 90° ShA
- pure PTFE rings (BKS)
- two coils pure PTFE rings (BK)
The following table shows the highest pressure allowed for anti-extrusion protected O-rings AP type regarding the clearance gap.