Copper alloy plumbing hardware, such as valves and tube couplings, and the treatment method for reducing elution of lead

Abstract

This invention relates to a plumbing device made of a copper alloy containing nickel salt, that includes a valve and a tube coupling having at least a liquid-contacting part washed 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 nickel salt, thereby performing nickel salt-removing treatment and causing the hydrochloric acid to form a coating film on the surface of the liquid-contacting part thereby effectively precluding elution of nickel salt from the surface of the liquid-contacting part in the presence of the coating film, wherein the nitric acid has a concentration c in a range of 0.5 wt %<c<7 wt % and the hydrochloric acid has a concentration d in a range of 0.05 wt %<d<0.7 wt % in the cleaning fluid, wherein the temperature is set to 10° C.≦x 50° C., and wherein nickel salt is removed with the cleaning fluid.

Dependencies are inferred from the claim text.