Understanding Oil Seal Types: TC, EC, VA/VS and More

Oil seals keep lubricants in and contaminants out of rotating shafts, and the design of the seal determines where it can be used. Understanding the differences between common types helps you select the right seal the first time.

TC Oil Seals are the workhorse of general industry. They feature a main sealing lip plus a dust lip, with a metal case for stability during installation. Suitable for shaft diameters from 6mm to 200mm, TC seals handle moderate pressure and speeds up to 10 m/s, making them the default choice for gearboxes, pumps, and conveyors.

EC Seals are engineered for high-pressure, high-temperature service. Built from FKM or FFKM compounds, they withstand up to 1.0 MPa and temperatures to 200°C, serving chemical processing, oil and gas, and power generation where standard seals fail.

VA/VS Seals are designed for valve stems and reciprocating motion, where low friction and precise fit matter more than raw speed. You will find them in engine valve systems and hydraulic control valves. Beyond these, bonded seals combine a metal washer with a rubber lip for high-pressure hydraulic fittings, and cassette seals integrate multiple sealing stages for wheel hub and heavy-duty rotating applications.

Matching the seal type to the application — shaft size, speed, pressure, and environment — is the difference between a long service life and an unexpected failure. When requirements go beyond standard catalog items, custom-engineered seals close the gap.