Double wall pipe overseas call Bundy tube. It is a unique copper strip was rolled and copper brazing technology to produce high-precision dedicated pipe. It is coated with a layer of a lower melting point than steel solder (typically copper) of the strip, after cold-formed into a double roll forming machine welded tube, and then through a special heating means, the interlayer welded together to form a double wall pipe.
      Double wall pipe has the following advantages: double wall pipe both the advantages of seamless and welded pipes, both seamless high-strength, but also high-precision welded pipe, while a certain extent, make up their own insufficient.
(1) with anti-vibration and high pressure rupture properties, the anti-vibration fatigue properties are 2-3 times higher than copper or aluminum pipe.
(2) has good processing properties, it can be bent to a small radius.
(3) high dimensional accuracy, good surface quality.
(4) relatively inexpensive.
The use of industry
      Double wall pipe is widely used in many parts of automotive brake systems and fuel line, carburetor public electricity box compressors, heat exchangers, condensers, as well as pneumatic machinery, agricultural sprinkler pipe. Double wall pipe is generally used as the raw material copper strip, copper from the solder junction media role in ensuring a strong steel pipe leak tightness. Other types of coatings can also be used for double wall pipe, such as zinc, nickel, tin-plated, hinges blessing, chrome and other.
      In general, the production of double wall pipe manufacturers have built a single-layer thin-walled pipe secret intelligence unit, in order to double, single pipe according to different uses, with each other fair use. In other countries, the production of single-precision thin-walled pipe to use more advanced DC welding or rectangular wave soldering.