Patents Assigned to Evalve Limited
  • Patent number: 4972874
    Abstract: In a power-operated valve in which the pressure of a working fluid is used to control the opening and closing of the valve member in dependence on the condition of an integral power-operated bleed valve, a compensation passage being formed in the valve member to permit working fluid to close the valve when the bleed valve is closed, the compensation passage is formed in that area of the valve member which is bounded by the valve seating and which also defines the cross-sectional area of the inlet chamber, whereby the closing force on the valve member is proportional to the area of the valve housing, thus enhancing the sensitivity of the valve. In a preferred embodiment, a filter is incorporated in the valve member to filter the working fluid to the compensation passage without filtering the bulk of fluid passing through the valve.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: November 27, 1990
    Assignee: Evalve Limited
    Inventor: Harold E. Jackson