What are some of the challenges of a dynamic seal?
Reciprocating motion between two members adds a major dimension to the sealing problem. Friction, and its accompanying wear, joins the list of factors which the design engineer must contend with; temperature, fluid compatibility, pressure. The seal used for sealing a reciprocating member must meet static sealing requirements at its contact area with the stationary member, and also seal effectively at its contact area on the reciprocating member.