Copper tube, also known as copper tube, is a kind of non-ferrous metal tube, is pressed and drawn seamless tube. Copper pipe has the characteristics of strong and corrosion resistance, so it has become the first choice for modern contractors to install water pipes, heating and cooling pipes in all residential commercial buildings. Copper pipe can be classified into general copper pipe, oxygen blowing copper pipe, galvanized copper pipe, metric copper pipe, wire sleeve, idler pipe, deep well pump pipe, automobile pipe, transformer pipe, welding thin-wall pipe, welding special-shaped pipe and spiral copper pipe.

(1) General copper pipe: general copper pipe is used to transport low pressure fluid. It is made of q195a, q215a and Q235A steel. It can also be made of other mild steel which is easy to weld. The copper pipe should be tested by water pressure, bending and flattening. There are certain requirements for the surface quality. Generally, the delivery length is 4-10m, and it is often required to deliver in fixed length (or multiple length). The specification of copper pipe is expressed by nominal diameter (mm or inch). The nominal diameter is different from the actual situation. According to the specified wall thickness, there are two kinds of copper pipe: ordinary copper pipe and thickened copper pipe. According to the form of pipe end, copper pipe is divided into two types with thread and without thread.

(2) Oxygen blowing copper pipe: it is used for steel-making oxygen blowing pipe. Generally, it is made of small-diameter welded copper pipe with specifications of 3 / 8-2-inch. It is made of 08, 10, 15, 20 or q195-q235 steel strip. In order to prevent corrosion, some of them are aluminized.

(3) Galvanized copper pipe: in order to improve the corrosion resistance of copper pipe, general copper pipe (black pipe) is galvanized. Galvanized copper pipe is divided into hot-dip galvanizing and electric steel zinc. The hot-dip galvanizing layer is thick and the cost of galvanizing is low.

(4) Metric copper pipe: the specification is seamless pipe, and the welded copper pipe is expressed by outer diameter * wall thickness mm, which is welded by hot strip and cold strip of common carbon steel, high quality carbon steel or general energy low alloy steel, or made by hot strip welding and cold drawing method. Metric copper pipe is divided into general energy and thin-walled, common used as structural parts, such as transmission shaft, or conveying fluid, thin-walled used to produce furniture, lamps, etc., to ensure the strength and bending test of copper tube.

(5) Bushing: it is also common carbon steel welded copper pipe, which is used in concrete and various structure power distribution projects. The commonly used nominal diameter is from 13-76mm. The wall of wire sleeve is thin, and most of them are used after coating or galvanizing, so cold bending test is required.

(6) Idler pipe: used for electric welding copper pipe of belt conveyor idler, generally made of Q215, Q235A, B steel and 20 steel, with diameter of 63.5-219.0mm. There are certain requirements for the pipe bending, end face to be perpendicular to the center line and ovality.

(7) Transformer tube: it is used for manufacturing transformer heat pipe and other heat exchanger. It is made of ordinary carbon steel. It is required to carry out flattening, expanding, bending and hydraulic test. The copper pipe is delivered in fixed length or multiple length, which has certain requirements on the bending degree of copper pipe.

(8) Special shaped pipe: square pipe, rectangular pipe, cap shaped pipe, hollow rubber steel door and window copper pipe welded by ordinary carbon bonded structural steel and 16Mn steel strip, mainly used for agricultural machinery components, steel windows and doors, etc.

(9) Welding thin-walled tube: mainly used to make furniture, toys, lamps, etc. In recent years, the thin-walled tube made of stainless steel strip is widely used, such as high-grade furniture, decoration, fence, etc.

(10) Spiral copper pipe: low carbon carbon structural steel or low alloy structural steel strip is rolled into tube blank according to a certain helix angle (called forming angle), and then the pipe seam is welded together. It can produce large diameter copper pipe with narrow strip steel. Spiral copper pipe is mainly used for oil and natural gas pipeline, and its specification is expressed by outer diameter * wall thickness. If spiral copper pipe has single side welding and double side welding, the water pressure test, tensile strength and cold bending performance of weld shall meet the requirements.