Patent ID: 6247679
Filing Date: 2001-06-19
Classification: F16K,Y10S,Y10T

Abstract:
In a valve of the type including:a. a body constructed to have(i) a fluid path;(ii) a stem bore connected in fluid communication with the fluid path; and(iii) a seat;b. a stem packing located in the stem bore;c. a valve member having a valve stem and a sealing member, the valve member being positionable in the stem bore so that the sealing member may engage the seat, the valve stem engaging the stem packing in the stem bore, the valve stem made of a base material; andd. an actuating member connected to the valve stem for actuating the valve member; the improvement comprising:the valve stem including a reduced diameter recessed section aligned with the stem packing and a section of welded hardfaced material filling the reduced diameter recessed section, having a thickness of between about 0.010 inches and about 0.125 inches thereby preventing damage to the hardfaced material under the action of foreign materials in the stem packing, and having a Brinell hardness number of between about 220 and about 380 in contact with said stem packing so that upon relative movement between the valve stem and the stem packing the welded hardfaced material filling the reduced diameter recessed section of the valve stem resists corrosion, erosion, and scratching due to foreign materials in the stem packing over a prolonged period of time; andan improved stem packing located in the stem bore in engagement with the hardfaced material and comprising at least one sealing member and at least one pair of metal pressure rings engaging the sealing member and comprising an upper metal pressure ring having a flat upper surface and a conical lower surface and a lower metal pressure ring having a conical upper surface and a flat lower surface.