Efalon®(PTFE)
Virgin Efalon®(PTFE) piston rings are used in cases that require very high chemical resistance and generally in low velocity and low pressure applications.
Carbon-filled Efalon®(PTFE) piston rings are most commonly used. They have very high resistance to wear and deformation under load and perfect wear resistance in dry and wet environments. They do not wear off the surface in contact even at high velocities. They have very high heat conductivity. Compared to types with other fillers, their resistance to alkalies is better, but their resistance to oxidizers is less than glass-filled.
Glass-filled Efalon®(PTFE) piston rings are recommended where chemical resistance is important. Their resistance is low only against alkalies. They can wear off surface in contact at high PV values if surface in contact is not hard enough. Compared to virgin PTFE piston rings, they have higher wear resistance and deformation resistance under load.
Bronze-filled Efalon®(PTFE) piston rings have highest heat conductivity, but their chemical resistance is not good. Generally speaking chemical environments that affect bronze have an effect also on bronze-filled PTFE. Their resistance to deformation and wear under load is good. They can be used at low and high PV values where chemical resistance is not necessary. If surface in contact is not too hard, they are also appropriate at high speeds in dry conditions.