| 摘要 |
PURPOSE:To enable the detection of leaked gas from a valve body and a valve seat of a door valve disregarding dropping of a liquid sodium, by arranging a plurality of detection holes for communication between a packing groove of a valve seat and the surface thereof and a detection hole for communication between two rows of packing grooves and an external detection piping. CONSTITUTION:A door valve 1 which is provided on the top of a closed container housing a internal component elements of a nuclear reactor holding a liquid sodium while an inert gas for a cover is sealed into the top thereof is made up of a valve box 2, a valve body 4 and a lower flange 3 as valve seat. The valve body 4 comprising a main valve unit 4a and a seal plate 3 runs through the valve box 2 with a drive screw 6. A space is forced in the packing grooves 3b and 3c of the valve seat 3 with an O ring packing 7 and a plurality of detection holes 3g and 3h are provided for communication between spaces 3e and 3f and the surface o the valve seat while a detection hole 3i connected to a detection piping 8 communicating with the spaces 3e and 3f. Thus, sound detection holes 3g and 3h remains even when the liquid sodium drops with the opening of the door valve 1 thereby enabling the detection of leaked gas at the contact surface between the valve body and the valve seat. |
