Patent ID: 7350765
Filing Date: 2008-04-01
Classification: F16K

Abstract:
1. A valve assembly comprising: a housing comprising a passage therethrough; a valve ball comprising a through hole, the valve ball disposed in the housing, wherein the valve ball is rotatable between an open position and a closed position, wherein in the open position the through hole is aligned with the passage, and in the closed position the through hole is misaligned with the passage; an upper seat disposed in the housing above the valve ball and biased toward the valve ball; and a lower seat disposed in the housing below the valve ball and biased toward the valve ball; wherein the valve ball is moveable in an axial direction between a lower position, a neutral position, and an upper position in response to pressure; wherein a prevention mechanism prevents sealing contact between the valve ball and the upper seat when the valve ball is in the lower position; and wherein the prevention mechanism prevents sealing contact between the valve ball and the lower seat when the valve ball is in the upper position.