Corrosion-resistant overlay for the edge of butterfly valves
AssigneeKeystone International Holdings Corp.
InventorDouglas G. Calvin
Life of this patent
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Abstract
An overlay for a valve disk of a butterfly or similar valve is formed from a strip of corrosion-resistant material. The strip is preferably profiled to conform to the edge of the disk and has an overall length less than the circumference of the disk. Both ends of the overlay are welded to the disk in closely spaced relation with the gap therebetween being filled by the weld metal. The disk also has a flow passage between the strip and its peripheral edge with first and second inlet ports leading from one disk face to intersect the flow passage. The inlet ports are closely spaced and lie on opposite sides of the weld. Sealant material introduced into one of the two ports flows in around the disk to form a complete seal between the disk and the overlay.
Claims6
A method for placing a corrosion-resistant overlay about a peripheral edge of a pivotal valve closure element comprising the steps of:
- providing a strip of corrosion-resistant material having a width at least equal to the width of the disk and a length less than the circumference of said disk;
- welding a first end of said strip to a first location on the peripheral edge of said disk;
- winding said strip about the circumference of said disk and welding said second end to said disk at a place close to but spaced from said first end to provide a space between said first and second ends and preventing rotation of said strip relative to said disk;
- and
- filling the space between said first and second ends with weld material to provide a continuous peripheral surface to prevent leakage.
Dependencies are inferred from the claim text.