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METHOD FOR PREVENTING ELUTION OF LEAD AND/OR NICKEL FROM COPPER ALLOY PIPING MATERIAL SUCH AS VALVE OR PIPE JOINT AND COPPER ALLOY PIPING MATERIAL, AND FLUID FOR USE IN CLEANING PIPING MATERIAL
METHOD FOR PREVENTING ELUTION OF LEAD AND/OR NICKEL FROM COPPER ALLOY PIPING MATERIAL SUCH AS VALVE OR PIPE JOINT AND COPPER ALLOY PIPING MATERIAL, AND FLUID FOR USE IN CLEANING PIPING MATERIAL
A technique is provided to precludes elution of the nickel by infallibly removing the nickel adhering to the inner surface of plumbing hardware, realize a treatment for efficient (treating temperature, treating duration, etc.) preclusion of both or either of lead and nickel and perform a neutralizing treatment on the varying fluid used in the treatment for precluding elution, thereby rendering the fluid usable as industrial water, permitting a generous cut in cost and allowing thorough observance of the influence on the environment. A method for precluding elution of lead and nickel from a plumbing device made of a copper alloy that includes a valve and a tube coupling, includes washing at least a liquid-contacting part of the plumbing device of a copper alloy containing both or either of lead and nickel with a cleaning fluid incorporating therein nitric acid and hydrochloric acid as an inhibitor under conditions of a temperature and a duration permitting effective removal of both or either of lead and nickel, thereby performing at least one of deleading treatment and nickel-removing treatment for a surface of the liquid-contacting part and causing the hydrochloric acid to form a coating film on the surface of the liquid-contacting part to thereby effectively precluding elution of both or either of the lead and nickel from the surface of the liquid-contacting part in the presence of the coating layer.
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