We mostly think of back up rings as being used with O-Rings. But they also are used with T-seals (an O-Ring substitute) as well as various styles of piston seals and occasionally with U-Seals.

Compression packing which is also called braided packing or rope packing.

Most fluid systems have fasteners that must be sealed. Face Seals feature an elastomeric sealing element molded in place within a metal retainer (washer).

Thread seals have been designed to seal the threads of machine screws, studs, and similar items.

Piston seals are popularly used for closing gaps or sealing off joints in hydraulic or pneumatic cylinders.

Choosing the proper material is as crucial to the success of an O-Ring as the design.

They are actually two different types of O-Rings. Encapsulated O-Rings are an O-Ring (usually silicone or FKM) covered with a Teflon tube.

Neoprene is a commercial name for polymers comprised of chloroprene. It is the first commercially successful substitute for natural rubber in the United States.

Chemraz® is a trademark of Greene Tweed and is a member of the perfluoroelastomer polymer family—polymers of three or more monomers in which all hydrogen positions have been replaced with fluorine.

DuPont™ Kalrez® perfluoroelastomer parts (FFKM) resist over 1,800 different chemicals, while offering the high temperature stability of PTFE (327°C).

O-RING FAILURE ANALYSIS

The sliding movements of components, i.e. a piston in a tube, risk metal-to-metal contact that will damage and score the surfaces and eventually cause seal damage, leakage and component damage.