Valve for liquid separation

A valve for selectively supplying fluid from an inlet port to an outlet port comprising a sealing element, a passage selectively opened and shut between the inlet and outlet ports by the sealing element, the passage and the sealing element being arranged so there is relative longitudinal back and forth movement between them in first and second opposite directions along a longitudinal axis such that when the sealing element is at (a) a first position relative to the passage along the axis the sealing element is disengaged from the passage interior surface to provide a fluid flow path between the inlet and outlet ports, and (b) a second position relative to the passage along the axis the sealing element engages a portion of the passage interior surface to form a seal between the inlet and outlet ports, the sealing element including a tapered peripheral surface extending generally in the direction of the axis, portions of the peripheral surface being sized and arranged for selectively engaging portions of the passage interior surface to form the seal, the tapered sealing surface having cross sections of progressively larger perimeters along the axis such that the cross-section of the sealing element sealing surface closest to the outlet port has the smallest perimeter that is closer to the longitudinal axis than any other cross-section of the sealing element sealing surface, the passage interior surface including a tapered surface having cross sections of progressively larger perimeters along the axis such that the cross-section of the passage interior surface closest to the outlet port has the smallest perimeter that is closer to the longitudinal axis than any other cross-section of the passage interior surface, the passage interior surface including first and second segments that are displaced from each other along the axis so that the first segment is closer to the outlet port than the second segment and the second segment is closer to the inlet port than the first segment, the perimeters of all cross sections of the second segment being greater than the perimeters of all cross sections of the first segment so all of the passage interior surfaces of the first segment are closer to the axis than all the passage interior surfaces of the second segment, the passage interior surface including a lip between adjacent portions of the first and second segments, the length of the lip in a direction at right angles to the axis being substantially less than (a) the distance between the axis and the perimeter of the cross-section of the first segment farthest from the outlet port and (b) the distance between the axis and the perimeter of the cross-section of the second segment closest to the outlet port, the tapered peripheral surface and the passage interior surface being sized, positioned and arranged so that (a) during initial movement of the sealing element from the first position toward the second position a flow path is provided between the inlet and outlet ports between the tapered peripheral surface of the sealing element and the passage interior surface including the first and second segments, and (b) as the sealing element continues to move toward the outlet port the tapered sealing surface of the sealing element engages the lip to form a seal and prevent fluid flow between the inlet and outlet ports, the spacings between the tapered sealing surface and the passage interior surfaces of the first and second segments while the flow path is provided during the initial movement of the sealing element being substantially less than (a) the distance between the axis and the perimeter of the cross-section of the first segment farthest from the outlet port, and (b) the distance between the axis and the perimeter of the cross-section of the second segment closest to the outlet port.

A valve for selectively supplying fluid from an inlet port to an outlet port comprising a sealing element, a passage selectively opened and shut between the inlet and outlet ports by the sealing element, the passage and the sealing element being arranged so there is relative longitudinal back and forth movement between them in first and second opposite directions along a longitudinal axis such that when the sealing element is at (a) a first position relative to the passage along the axis the sealing element is disengaged from the passage interior surface to provide a fluid flow path between the inlet and outlet ports, and (b) a second position relative to the passage along the axis the sealing element engages a portion of the passage interior surface to form a seal between the inlet and outlet ports, the sealing element including a tapered peripheral surface extending generally in the direction of the axis, portions of the peripheral surface being sized and arranged for selectively engaging portions of the passage interior surface to form the seal, the tapered peripheral surface having cross sections of progressively larger perimeters along the axis such that the cross-section of the sealing element sealing surface closest to the outlet port has the smallest perimeter that is closer to the longitudinal axis than any other cross-section of the sealing element sealing surface, the passage interior surface including a tapered surface having cross sections of progressively larger perimeters along the axis such that the cross-section of the passage interior surface closest to the outlet port has the smallest perimeter that is closer to the longitudinal axis than any other cross-section of the passage interior surface, the passage interior surface including a lip, the tapered peripheral surface and the passage interior surface being sized, positioned and arranged so that (a) during initial movement of the sealing element from the first position toward the second position a flow path is provided between the inlet and outlet ports between the tapered peripheral surface of the sealing element and the passage interior surface, the lip being arranged to deform slightly in response to the sealing element continuing to move toward the outlet port from the initial sealed state between the lip and the peripheral surface along the axis to provide an annular seal having a length in the direction of the axis that increases from the length of the annular seal when initial contact occurs between the sealing element peripheral surface and the lip.