One or a few Efalon^®(PTFE) wear rings are used in order to prevent metal to metal friction between piston and cylinder. The most important function of wear rings is that, carrying the weight of the piston, they do not transfer bearing load to piston rings and thus prevent piston-cylinder contact. These rings can't be operated as piston rings; they don’t hold compression.

• Efalon^®(PTFE) has the least coefficient of friction among all solids.
• Nothing sticks onto the surface of Efalon^®(PTFE).
• Heat and pressure do not alter this property.
• Are perfectly weatherable and impermeable.
• Are 100% resistant to chemicals within operation temperature interval of -260ºC,+270ºC.
• Efalon^®(PTFE) is a very good electrical insulator.