Method of making dual graphite structured pipe
AssigneeUnited States Pipe and Foundry Company
InventorsAndrew B. Malizio, Robert W. Jennings
Life of this patent
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Abstract
A heavy wall monolithic iron pipe comprises nodular graphite in the outer portion of its wall and flake or quasi-flake graphite in the inner portion of its wall and a method for making the pipe. The central portion of the wall of the pipe may be a combination of nodular graphite and flake or quasi-flake graphite.
Claims9
The method of making a centrifugally cast heavy wall iron pipe having a monolithic wall, said monolithic wall comprising an outer portion containing nodular graphite, and an inner wall containing flake and quasi-flake graphite, comprising the steps of making a molten mass of iron suitable for casting in a cooled metal mold in the conventional DeLavaud process, admitting said molten mass to a metal mold, rotating said metal mold to form a centrifugally cast molten mass, and chilling said centrifugally molten mass to form said pipe with said monolithic wall, said pipe having between about 0.01% by weight and 0.03% by weight of magnesium, and between 0.004% by weight and 0.006% by weight of sulfur.
Dependencies are inferred from the claim text.