The improved seal for a sliding gate valve includes an annular lip arranged around the valve passageway with the proximal end of the lip secured to the valve housing and the distal end of the lip extending flexibly and generally horizontally inward around the periphery of the valve passageway so that the distal end of the lip is movable axially of the passageway. Gate ValvesThe gate side of the lip has a ridge confronting the gate between the distal and proximal ends of the lip, and the surfaces of the lip on opposite sides of the ridge are inclined away from the gate at acute angles in the normally assumed position of the lip. Resilient Seated Gate ValvesThe lip is thickest in the region of its ridge, and has substantially equal and uniform thickness on opposite sides of the ridge.

The cammed gate has a plurality of cam followers arranged on the side of the gate opposite the seal, with the housing on that side of the gate having a corresponding plurality of cams outside the valve passageway and arranged so that cams and cam followers move the gate axially of the passageway against the seal as the gate nears its closed position to force the gate against the seal for sealing the passageway closed.

The inclined surfaces of the lip adjacent the ridge facilitate camming of the gate against the ridge as the gate is slid against the seal,Gate Valves and the inclinations on each side of the ridge ensure that such camming is successful at both the near and far sides of the seal as the gate slides across the seal. Camming of the gate against the seal is particularly successful with the inventive seal and allows the gate to be made of lighter construction and to move freely and easily across the seal and yet make an effective and reliable sealing engagement with the seal, without excessive wear.

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