Copper tube is an important raw material in refrigeration devices, mainly used to make heat exchangers and connect pipes and fittings. Most of the pipe fittings for refrigeration and air conditioners are made of copper pipes. The solders used to connect copper pipes include copper-phosphorus solder, silver-copper solder, copper-zinc solder, etc. In brazing these cooper pipes,, the correct solders should be chosen according to the characteristics of the pipeline materials and skilled operation is required to ensure the quality of brazing.
1. Brazing of same type of materials - cooper to cooper
Phosphorus copper solder or phosphorus copper solder with low silver content can be used, such as 2% or 5% silver-based solder. For example, Fox Alloy BCuP-2, BCuP-6, and BCuP-3 solders, they are relatively cheap and have good melt fluidity. No flux is needed if pre-heating process is applied in filling solder jobs.
2. Brazing of different materials
(1) Brazing of copper to steel or copper to aluminum
Fox Alloy silver-copper solder BCuP-3 and BCuP-5 are good choices for this kind of brazing jobs, and appropriate flux can be used when necessary. After brazing, the residual flux near the brazing joint should be removed with hot water or steam to prevent corrosion. When using flux, it is best to dilute it into paste with alcohol and apply it on the surface of the brazing joint. The alcohol evaporates quickly during brazing and form a smooth film that is not easy to lose, and at the same time avoid the danger of water immersing in the refrigeration system.
(2) Brazing of copper to iron
Fox Alloy phosphor copper solder BCuP-3 or brass rods S221 can be used, but the corresponding flux, such as borax, boric acid or boric acid mixed flux, will be required.
3. Functional distinction between phosphor copper rod and silver copper rod:
(1) Phosphor copper rod has certain strength, good plasticity, impact resistance, wear resistance and corrosion resistance. It is characterized by good brazing process performance and great versatility. Suitable for brazing the same and dissimilar metals such as pure copper, brass, and phosphor bronze, widely used for surfacing of phosphor bronze bushings, ship propeller blades, etc., and can also be used for brazing repair and surfacing of cast iron.
(2) Silver-copper rod has excellent process performance, low melting point, good wettability and ability to fill gaps, high strength, good plasticity, good conductivity and corrosion resistance, and can be used for brazing all ferrous and non-ferrous metals other than low-melting point metals like aluminum and magnesium. This product is widely used in industrial manufacturing fields such as refrigeration, lighting, hardware and electrical appliances, instruments and meters, chemicals, and aerospace.
Packing specification:
Flat bars: 1.3*3.2*350mm 20pcs/tube
Round rods: 2.0*200mm 20pcs/tuble