Properties:

An item constructed of one or more layers of thin flexible material, either laminated or separated, designed to form a tight seal between the chambers of a valve, and to transmit pressure inducted motion to a valve disk either directly or through a mechanical linkage. The surface of the item must be formed or molded to have a beaded or rolled edge, ribs or any other raised surfaces. The item may contain bolt holes and/or center holes. Excludes diaphra gm, valve, flat and gasket.