20110233437 | VALVE - A valve is provided having a flow passage interrupted by a plug chamber interposed in the flow passage. The plug chamber adapted to receive a rotatable valve plug inserted through the plug aperture and seated on the valve seat. The rotatable valve plug comprising a plug flow passage for fluid communication with the valve flow passage and extending through the plug and a pair of opposed resilient sealing region for the flow passage when the rotatable valve plug is oriented in a closed position. The sealing region presenting a leading edge at an obtuse leading edge angle relative to a portion of a wall of the plug chamber surrounding the flow passage, such that as the sealing region transitions into sealing engagement with the portion of the plug chamber wall as the rotatable valve plug is rotated from an open position to the closed position, the elastomeric seal is compressed substantially radially to form a seal against the plug chamber wall but not substantially deflected in a direction opposite to the direction of rotation. The sealing region presenting a trailing edge at an obtuse trailing edge angle relative to a portion of a wall of the plug chamber surrounding the flow passage, such that as the sealing region transitions into sealing engagement with the portion of the plug chamber wall as the rotatable valve plug is rotated from the closed position to the open position, the elastomeric seal is compressed substantially radially to form a seal against the plug chamber wall but not substantially deflected in a direction opposite to the direction of rotation. | 09-29-2011 |