Composite lip seal for lavatory or sink valve

摘要

A valve control stem extends through a thick sleeve-like sealing member fitted in a valve body. The sealing member has a short passage linking a body inlet port with the control stem. The passage has an intermediate enlargement forming an atrium or pressure chamber. The chamber forms outer and inner lips which are urged by supply pressure to seal against the valve body on the outside and (in the OFF position) against the control stem on the inside. A ring insert in the atrium provides a mechanical assist positively forcng the lips into sealing position and corrects for any imperfections in the lips that might otherwise prevent initiation of a proper seal. A reliable and effective seal is achieved.