Preparatory work for
Before the soldering process is carried out, a number of preparatory work must be carried out. The main condition is the presence of a permanent gap between the two parts. Therefore, the surfaces to be bonded must have a cylindrical shape. And it is important that there are no defects that often occur when cutting pipes( burrs, uneven cutting, deformation of the material).To avoid them, it is necessary to cut it as flat as possible, and then to clean the ends.
You can also eliminate the defects that have already appeared with the help of a manual template. Cleaning from the oxide film and mechanical impurities is done using sandpaper and a metal brush. After passing through the surface to be treated with a dry cloth. The strength of the connection depends on the purity of the base. Further active chemicals - fluxes are applied. They are needed for better distribution of liquid solder.
And then copper pipes are soldered, a video lesson about which is presented on our website. When soft soldering( up to +450 ° C), usually rosin is used as fluxes with a solvent or alcohol, as well as wood resins, hydrazine, petrolatum and others. Apply a small amount of the formulation and remove the residues( to avoid corrosion).With a solid, high-temperature brazing( more than +450 ° C), the flux is not used, only the mechanical cleaning of the substrate is carried out.
How to braze copper pipes at low temperature?
If you want to know how to solder copper pipes, the video with the process is presented on our portal. But, in addition, give detailed instructions. As already mentioned, they can be connected by a high-temperature and low-temperature method. So, how correctly to solder copper pipes at low temperature? First, the surface is heated by propane burners at temperatures up to + 200-250 ° C.Then, solder( metal) is applied to the parts that need to be connected. Carry out soldering. The width of the seam should be from 7 to 50 mm.
As solder, low-melting metals are used: lead, tin and all their alloys.
Use this type of welding( low-temperature capillary) only for pipes with a diameter of 6-108 mm. Subsequently, they are used for heating and water supply pipelines( sanitary, for example, in the arrangement of the sewage system in the house, including the pressure sewage system) from t to 130 ° C.Soldering with lead is prohibited in gas supply and drinking water supply because of its toxicity.
How to solder copper pipes at high temperature?
This technology of soldering copper pipes is carried out at a temperature above +450 ° C.Connection method - gas flame( gas flame welding, where acetylene air, oxygen-propane, sometimes oxygen-acetylene is used).First, the surface also heats up. Then solder is applied from more solid metals( this can be solder based on silver and copper).The connection is in progress. Thanks to the use of these metals, a high-strength and reliable seam is provided.
The feature of soldering by this method is that when the metal is annealed, it begins to soften. Therefore, for the least loss of strength characteristics, natural cooling( air) is made, and it is desirable to make the heating of the surface minimal. Brazing of copper pipes with brazing is suitable for solar systems and distribution gas pipelines. This method is also used for heating and water supply pipelines.