Double plate gate valve

provided dual knife gate valve (10), whose blocking plates (16, 17) can be displaced by an actuating rod (21), and with a pipe bridge (22), which has two sealing rings (23, 24) which in the open position of the slider with corresponding housing sealing seats (14, 15) of the slider housing (11) are in operative engagement, characterized in that at least one of the two housing sealing seats (14, 15) in the open position of the slider (10) which by the action of an elastic element (25) on or to the of the pipe bridge (22) associated sealing rings) (23, 24) and in the closed position of the slider on the peripheral edge of the blocking plate (s) is applied under a predetermined pressure.