This design, used in a wiper packing assembly, consists of a three ring set; a male radial
ring, female radial ring and tangent cut ring as shown above. The wedge packing set is
installed facing the cylinder with the female radial ring facing the pressure. The purpose of the
wedge packing is to prevent the gas from getting into the crankcase.
It can also be utilized in very low pressure applications where the radial tangent pair does not
exert sufficient force on the piston rod to create a seal. The male/female combination load
ring creates sufficient force on the rod with the expansion of the PTFE material due to a
temperature increase at operating pressure. This pressure allows the ring to seal where the
normal downward force of the gas on the packing ring is not sufficient.
