Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°-50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°-25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: A method is provided for forming an inorganic layer on a surface of a copper material, made of copper or of a copper-based alloy: a browning anodic oxidation process is performed on the copper material in an electrolytic bath containing only an alkali (for example NaOH) at a specified concentration in aqueous solution, under controlled condition of temperature and anodic current density and for a period of time suitable to form a continuous layer basically formed of copper (I) oxide (Cu2O): layers highly adherent to the copper substrate and having good mechanical behavior are produced: different colors and optical properties may be obtained by controlling the process conditions so as to influence the crystalline form of the Cu2O layers.

Abstract: A substantially rectangular-section casting conduit of an ingot mold, for continuous casting of molten metal, is divided into two portions; a first portion has a variable inner section, by having rounded inner edges with a radius of curvature decreasing gradually in the flow direction of the molten metal along the conduit; the second portion is consecutive with the first portion, and has a constant inner section with rounded inner edges of a predetermined optimum radius of curvature for subsequent rolling operations. The design of the first portion of the casting conduit prevents the metal, as it cools and contracts through the conduit, from detaching from the walls, and in particular from the edges, of the mold, thus enabling an increase in casting speed with no fall in product quality.

Abstract: A method is provided for forming an inorganic layer on a surface of a copper material, made of copper or of a copper-based alloy: a browning anodic oxidation process is performed on the copper material in an electrolytic bath containing only an alkali (for example NaOH) at a specified concentration in aqueous solution, under controlled condition of temperature and anodic current density and for a period of time suitable to form a continuous layer basically formed of copper (I) oxide (Cu2O): layers highly adherent to the copper substrate and having good mechanical behaviour are produced: different colors and optical properties may be obtained by controlling the process conditions so as to influence the crystalline form of the Cu2O layers.

Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°-50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°-25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°−50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°−25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: Lead brass components for potable water distribution circuits (e.g., plumbing components made of CuZn39Pb3, containing 3% Pb), also chronium plated ones, are subjected to a lead-selective surface etching to reduce, in operation, the release of Pb caused by Pb surface “smearing”, resulting either from machining or molding; said elements are firstly contacted by an aqueous solution of an acid capable of forming soluble Pb salts, preferably a non-oxidizing solution, by simply dipping the components in the solution, e.g., a solution of 0.1 M sulfamic acid, at 20°-50° C. for 10 to 50 minutes, and, subsequently, the elements are passivated by immersion into a strong base aqueous solution, e.g., a solution of 0.1 M NaOH at 20°-25° C., for approximately 10 minutes; in this manner, plumbing components made of a copper based alloy containing Pb are obtained, which components, after 15 days of test according to US NSF STD61 procedure, release Pb in an amount less than 0.

Abstract: A method for treating a component made of a copper-based alloy containing lead. The component has Pb and Pb salts on a surface thereof. The method includes the step of etching the surface of the component selectively to remove almost entirely the Pb and Pb salts from the surface. The etching includes treating the surface with an acidic aqueous solution that is a) a non-oxidizing acidic aqueous solution of an acid capable of forming soluble Pb salts or b) an oxidizing acidic aqueous solution of an organic acid mixed with peroxide. The method also includes the step of passivating the etched surface whereby to inhibit release of any Pb or Pb salts remaining in the component when the passivated surface is in contact with water.