Contiweld CuP7 Copper Brazing Rod
Contiweld CuP7 Copper Brazing Rod
Contiweld CuP7 is a copper-phosphorus brazing rod used on the copper pipe joints of air conditioning and refrigeration systems. The phosphorus reduces the oxide on the copper surface as brazing proceeds, which is why no separate flux is needed on copper-to-copper joints. The result is a faster, cleaner joint that leaves less residue behind.
Why copper-phosphorus brazing?
- Flow — the melt is drawn into the capillary gap by itself and leaves no void in tight-tolerance fitting seats.
- No flux — on copper-to-copper joints there is no flux residue and no clean-up afterwards.
- Pressure strength — a correctly made joint withstands the working pressure and vibration of a refrigerant line.
- Repeatability — a consumable that behaves the same way every time on site, which installation crews come to rely on.
Application notes
Mating surfaces must be clean, free of oil and free of burrs. Heat is applied with a flame (oxy-acetylene or propane); the area should be heated evenly up to the melting temperature of the alloy, and the rod should touch the heated copper rather than the flame itself. Purging the line with nitrogen throughout brazing prevents oxide scale forming inside the pipe and being carried into the compressor.
Note: copper-phosphorus alloy alone is not sufficient for joints to materials other than copper (brass, bronze, steel). Those joints require an appropriate flux, and silver-based alloys should be preferred on steel.
About the range
Contiweld brazing rods are offered under different codes according to silver content (CuP3, CuP6, CuP7 and so on). A higher silver content lowers the melting range of the alloy and improves the ductility of the joint; which code suits your application depends on pipe diameter, line pressure and installation conditions. Ask the Lapin team for the right selection and the current technical data sheet.
Request a quotation for rod sizes and packaging options (boxes sold by the kilogram).