Kontraventil

摘要

The check valve comprises a valve body having a piston receiving recess and at least one inlet port extending through an otherwise closed end of the body. A piston is located in the piston receiving recess, having a face at one end and a recess in its opposite end. A valve cone is retained in the valve body recess axially outwardly of the piston recess. A first seal is positioned between the face of the piston and the end of the valve body to form a seal around the one inlet port when the valve is in a closed configuration. A second seal is positioned between a wall of the piston recess and a surface of the valve cone, thus creating a sealed gas chamber. A piston drive is positioned between the piston and valve cone to move the piston to its closed position when fluid ceases to enter said at least one inlet port.