Reciprocating seals are a dynamic version of either a male radial or female radial O-ring design. In a reciprocating seal, there is relative reciprocating motion (along the shaft axis) between the inner and outer elements. This motion tends to slide or roll the O-ring, or sealing surface of the O-ring, back and forth with the reciprocal motion. Examples of a reciprocating seal would be a piston in a cylinder, a plunger entering a chamber, and a hydraulic actuator with the piston rod anchored.
Note: O-rings are generally not recommended for reciprocating installations in which the speed is less than one foot per minute. Consult a Parker Territory Sales Manager for more information on special seals to meet this requirement.