Abstract: A conduit pipe for conveying media, having a core pipe made of a copper alloy and a jacketing made of a plastic material from the group of the polyolefins having functional groups. The ratio between the thickness of the jacketing wall and the thickness of the core pipe wall ranges between 2:1 and 14:1, while the ratio between the thickness (D) of the core pipe wall and its inside diameter (ID) ranges between 0.01 and 0.05.

Abstract: A conduit pipe (1) is described for conveying media, having a core pipe (2) made of a copper alloy and a jacketing (5) made of a plastic material from the group of the polyolefins having functional groups. The ratio between the thickness (D1) of the jacketing (5) wall (6) and the thickness of the core pipe (2) wall (4) ranges between 2:1 and 14:1, while the ratio between the thickness (D) of the core pipe (2) wall (4) and its inside diameter (ID) ranges between 0.01 and 0.05.

Abstract: In a method for reducing copper solubility at the inner surface of a copper tube, the process parameters surface treatment (degreasing and pickling), flow conditions (flow speed<1 m/s), temperature (50° C. to 80° C.) and time (1 min to 10 min) are purposefully adjusted to one another, so as to achieve a uniformly directed crystal growth during the course of the tin coating. In particular, the planes (101) of the copper crystals and the tin crystals are aligned parallel to one another and the directions [101] are aligned perpendicular to one another.

Abstract: A copper strip or sheet having a red-brown to dark brown cover layer. The cover layer includes a first layer of Cu.sub.2 O which adheres to the base metal, with a thickness in the range of 0.05 to 5 .mu.m, preferably in the range of 0.1 to 1 .mu.m, and a second layer of CuO arranged on top of the first layer, with a thickness between 1 and 100 nm, preferably with a thickness between 10 and 50 nm. The cover layer is applied by heat treating the copper base to form a Cu.sub.2 O layer, followed by a second heat treatment to form a CuO layer. Alternatively, the cover layer is applied by heat treating the copper base in an oxygen containing atmosphere followed by treatment with an aqueous solution of a salt which produces an alkali reaction. The resulting copper strip or sheet of the invention is well suited for use in the construction sector.

Abstract: An improved corrosion resistant pipe and method of manufacture is presented wherein a phosphorus copper or phosphorus copper alloy pipe is subjected to a special heat treatment step which forms an internal oxide coating. A pipe produced in accordance with the invention is characterized as having a carbon content on the inside wall of 0.05 mg/dm.sup.2 or less and an internal oxide coating having a thickness ranging from 0.1 to 5 microns. Notably this improved pipe has a good resistance to corrosion, even when exposed to chemically agressive liquids.