A sleeved plug valve having flow-throttling lug members at the ports in the valve body, such lug members constituting raised, islandlike projections from the walls of the valve chamber located immediately adjacent the side edge of the ports in the direction of throttling or closing plug movement, SAFETY VALVES such lug members extending circumferentially of their respective ports only along such side edge and having a length which is only a minor portion of the total port circumference, and such lug members having a minimum width at their widest point which is a function of the maximum port dimension of the valve. In a plug valve,Balance Valves of the type having a valve body with an elongated generally cylindrical interior chamber defined by walls having at least two port openings therein communicating with said chamber,Plug Valves having an elongated plug member with a through port movably disposed within said chamber to control flow therethrough between predetermined such port openings, and having an elongated generally sleevelike liner means seating said plug within said chamber and defining openings disposed generally in registry with said port openings, the improvement comprising: a lug member located adjacent at least one of said port openings, in lateral alignment with at least a portion of said plug port and at the side of such port opening toward which the plug is movable to close the valve, said lug member comprising an islandlike projection from and integral with said chamber wall into said chamber and generally toward the central area thereof; said lug member having a length dimension in a direction circumferentially of such port opening which is only a minor portion of the total circumference of such opening; said lug member having a side edge which defines its width and which is spaced from said port opening side in said direction of plug movement; and the said liner member opening which is in general registry with such port opening having an edge extremity lying in juxtaposition to and in flanking relation with such lug member side edge and wherein said lug member has a width at its widest point which is at least on the order of one-eighth its said length. In a lines plug valve, having an elongated plug movable seated in a valve chamber and having a liner disposed generally between the plug and the walls of the chamber, said plug controlling flow between at least a pair of ports leading into and out of each chamber by selective positioning of a passage in said plug with respect to such ports, the improvement comprising: a flow-throttling lug disposed laterally adjacent at least one of said ports and extending generally circumferentially along at least a portion of the peripheral edge thereof; said lug projecting away from and integral with portions of said chamber walls generally around such port and extending toward the interior of said chamber a sufficient extent to form a narrow open space between the inner end extremity of the lug directly adjacent the outer surface periphery of said plug, and said inner end of said lug having a shape generally complementary to the outside of said plug, such that the plug sweeps across the lug end extremity when moved in a flow-stopping direction to throttle flow directly between the lug and the plug; and said lug having a width dimension in such direction of plug movement which is at least on the order of one-sixteenth the major diametral dimension of the port to which the lug is adjacent.

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