Valves

摘要

A valve comprises a valve seat member and a movable valve member (preferably a disc with at least one face coated with piezo electric material) movable towards and away from the seat to close and open the valve and a sealing element made from a resilient material and attached to one of the members. The sealing element possesses an initial deformable characteristic so that initial closure of the valve causes the seating element to substantially conform to the shape of the other member and retain the so-conformed shape. The sealing element comprises first and second springs of different resiliently formable characteristics, the second spring preferably being a ring of elastomeric material, and the first spring-after initial deformation of the sealing element-being rigidly adhesively secured to the valve seat member.