Abstract: A fluid seal for a liquid and gas-filled damper mechanism. The seal includes a casing and a primary lip body subdivided into two portions, one portion being adapted to provide a fluid seal with an associated reciprocable rod, and the other to provide a one-way relief valve action to bleed fluid from one side of the lip body to the other when higher pressure is on the rod side; and to increase the sealing force when the higher pressure is on the other side of the lip body opposite the rod.

Abstract: A seal unit having a casing portion and an elastomeric seal body bonded thereto, with the seal body including an excluder lip, a primary liquid seal lip and a separate gas or vapor sealing lip. The primary and secondary lips insure against leakage in both the static and dynamic conditions of the seal. While gas or vapor sealing lip is seated against the valve body of an associated mechanism. The gas or vapor lip in effect provides a relief valve action and is able to be urged into a position of engagement with another part of an associated machine member by its own inherent resiliency. The relief valve bleeds gas and liquid in one direction but not in the opposite direction.