Three port non-interflow poppet valve

摘要

The valve element of this invention is generally cylindrical and has poppet valves at both ends for contact with seats at opposite ends of a chamber in which the valve element moves. Cylindrical side walls at each end of the chamber prevent interflow between ports during movement of the valve element from one end of its stroke to the other. For sub-sea use on offshore drilling well heads, a spring that moves the valve element in one direction is in a chamber sealed from an adjacent chamber to which the ambient sea water has access. Apparatus for pilot operation of the valve element has spaced, aligned bearing guides for guiding the valve element on opposite sides of an intervening chamber that holds the sea water.