The AD 51 is a double-acting wiper. It provides a double function wiping the dirt from the rod and retaining the residue oil film with the second lip. The retained oil can be returned to the system through a leakage bore hole.
Double wipers made of NBR are used in hydraulics and pneumatics. They are suitable for piston rods with high stroke speeds. Due to the additional diameter step on the outer fit, the AD 51 provides better sealing and exerts a stronger wiping force on the rod.