DOUBLE DISC GATE VALVE WITH REPLACEABLE SPACER RING

摘要

DOUBLE DISC GATE VALVE WITH REPLACEABLE SPACER RING A gate valve includes a pair of identically shaped tapered discs defining a tapered self-locking axially translatable gate wherein each disc has an annular hardened seating surface which engages the mating surfaces on the valve body adjacent the flow ports. Tongues on the sides of the discs ride in vertical grooves on the valve body as the gate travels between a raised open and a lowered closed position. The discs are separated by an annular spacer ring of substantially smaller diameter than the seating surfaces surrounding an interlocking segmented hub formed on the inner juxtaposed surfaces of the discs, the arrangement being such that the spacer ring can be sized to establish an overall gate width which will ensure that the seating surfaces are making proper sealing engagement with the valve seats with the diametral differences increasing the disc flexibility. The spacer ring can be replaced by an appropriately sized spacer ring to compensate for thickness reduction in resurfacing the seating surfaces. The discs of the gate are provided with a slot transverse to the flow ports which captures a T-head on the stem assembly, the slot being positioned in the gate interior radially within the seating contact area to thereby reduce the overall height of the valve.