Flow shut-off valve device

A shut-off valve assembly comprising:

• a valve housing having a fluid flow conduit extending therethrough and a valve-seating surface within the fluid flow conduit;
• a valve member having a proximal end and a distal end, the valve member being axially movable between an open position and a closed position such that advancing the valve member distally moves the valve member to the closed position and proximally retracting the valve member moves the valve member to the open position, wherein the valve member is a single component;
• a proximal handle attached to the proximal end of the valve member and configured for moving the valve member between the open and closed positions;
• and
• a valve-seal attached to the distal end of the valve member and configured to sealingly engage with the valve seating surface when the valve member is in the closed position, wherein when the valve member is in the closed position, the valve member and/or the valve-seal includes a proximal facing surface in fluid communication with a pressurized fluid upstream from the valve-seal such that the pressurized fluid upstream of the valve-seal provides a force component in the distal direction against the proximal facing surface to provide a positive sealing pressure, wherein the valve-seal comprises a bulbous feature disposed near the distal end of the valve member that sealingly engages with the valve-seating surface when the valve member is in the closed position, the bulbous feature comprising a spherical or semi-spherical surface that is circumferentially engageable with the valve-seating surface,
• wherein the valve member comprises at least two flanges near the valve-seal between which is disposed an o-ring to seal the valve member to the valve housing, wherein the at least two flanges, in combination with the o-ring, the valve housing and the valve-seal, define a chamber diverted from in-line flow when the valve member is in the closed position, the chamber being in fluid communication with fluid upstream from the valve-seating surface so as to provide the positive sealing pressure when the valve-seal is engaged with the valve-seating surface.

A method for controlling fluid flow, said method comprising:

• providing a valve assembly having a valve housing having a fluid flow conduit therethrough and a valve member disposed therein, the valve member being a single component having a proximal end and a distal end, and a valve-seal attached to the distal end that is sealingly engageable with a valve-seating surface within the fluid flow conduit of the valve housing;
• replacing a conventional valve assembly in a fluid dispensing system with the valve assembly, the conventional valve assembly having a rotatable ball-type seal for sealing fluid flow in a portion having in-line fluid flow through the valve assembly;
• diverting the fluid flow from in-line flow to an upper chamber in a portion of the valve assembly that corresponds to the portion of the conventional valve assembly having in-line flow, wherein the upper chamber is defined by the valve housing, a flange of the valve member and associated o-ring, and the valve-seal when the valve member is in the closed position, so that the pressurized fluid upstream from the valve-seal provides a positive sealing force;
• distally advancing the valve member along a longitudinal axis of the valve member from an open position to a closed position by imparting rotational movement to the proximal end of the valve member in one direction, wherein when in the closed position, the valve-seal is sealingly engaged with the valve-seating surface so as to prevent fluid flow through the conduit and pressurized fluid upstream of the valve-seal provides a force component in the distal direction against a proximal facing surface of the valve member and/or the valve seal to provide a positive sealing pressure;
• and
• proximally retracting the valve-seal along the longitudinal axis of the valve member by applying rotational movement to the proximal end of the valve member in an opposite direction, wherein when in the open position, the valve-seal is positioned a distance proximally away from the valve-seating surface so as to allow fluid flow through the conduit.