Soldering of copper pipes: technology, features of execution
The use of copper pipes makes it possible to arrange an efficient and durable heating or water supply system. The simplest and most common way to connect such products is soldering technology. It assumes the presence of solder - a thermoplastic substance, which provides sealing of the joint by melting and flow under the action of high temperature. After cooling, it hardens and fixes the connection.
Soldering of copper pipes is carried out by different types of solder
Preparation of copper pipes
These products are durable, durability, withstand high values of pressure and temperature, and are not afraid of ultraviolet radiation.
You will need a pipe cutter to weld the copper pipes, expander, hammer, tape measure and chamfer. The choice of pipe cutter is determined by the diameter of the products used. It allows you to get a smooth cut, which is perpendicular to the axis of the pipe. Chamfer removers are used to remove the grille and chamfer from the edges of the products. Removing burrs from the outer and inner edges of the pipes facilitates their insertion into each other. Bevel removers come in a round case (with a limit on the diameter of the pipe in 3,6 cm) or in the form of a pencil.
If the connection of copper pipes does not involve the use of fittings, then a pipe expander is used.
Importantly! The expandable copper product must be either soft or annealed.
There must be no flammable or combustible substances in the copper pipe soldering room. It is also necessary to provide good ventilation and ventilation.
A straight cut is important for a good connection, therefore the pipe needs to be cut by the special device - a pipe cutter
Materials, necessary for work
Soldering of copper pipes can be performed independently. You will need it to work:
- solder;
- steel brush;
- flux;
- brush;
- soldering iron or gas burner.
The solder has the form of a wire with a melting point lower, than in copper. This allows the products to be connected by heating. With the help of a steel brush during the preparatory work the inner surface of the fitting and the outer part of the pipe are cleaned.
Solder is high temperature, which is a thin copper wire with the addition of 6% phosphorus and has a melting point 600-800 ° C, and low-temperature - from tin, melt at 300-400 ° C.
Liquid flux is applied to the coupling and pipe before assembling the coupling assembly, solid - melts in the soldering zone. Flux in the form of a paste is a thickened mixture, which can be applied as to, and after the docking process. The flux cleans the surface of the pipe from oxides, protects the soldering spot from oxygen, promotes the spread of solder and improves the adhesion of the connected parts.
A gas burner is required to heat the metal and solder
There are gas burners with a stationary cylinder or disposable. There is a separate type of burner - acetylene-oxygen, which differ in their design. The choice of power of the soldering machine is based on the melting temperature of the solder. Professional tools are used for soldering copper pipes with hard solder, semi-professional - hard and soft solder.
Features of solders and fluxes
There are many hard and soft solders, which can provide high-quality soldering of copper pipes. Low-temperature solders give a seam with slightly worse mechanical parameters, but allow you to perform work at temperature, which does not have a strong effect on the strength of the metal pipes. Close 95-97% such solders are tin, the rest are other elements.
The best technological properties of the compounds, containing silver. There are three-component solders, which include tin, silver, copper. Fluxes, used for soldering, often contain zinc chloride.
Sufficient strength of the joint when soldering with soft solder is achieved by a large contact area of the elements. Only high-temperature soldering is used for gas pipelines, which provides the best strength and reliability.
The low-temperature solder consists of tin and has the form of a wire
Permissible pressure in pipelines when using different types of soldering is given in the table.
Table 1
| Soldering type | Ambient temperature, transported, ° W | Pressure, atm |
| Low temperature | Thirty | Sixteen |
| Sixty-five | Ten | |
| One hundred and ten | Six | |
| High temperature | Thirty | Fourty |
| Sixty-five | Twenty five | |
| One hundred and ten | Sixteen |
Copper-phosphorus solders are usually used for high-temperature soldering. They are available in the form of rods.
pay attention! Copper-phosphorus solder can be used for soldering cast iron, steel, as well as non-ferrous metals, which includes more 10% nickel.
It is recommended to use flux and solder from the same manufacturer as for low-temperature, and high-temperature soldering.
Soft soldering
Low-temperature soldering is used in the installation of water and heating networks with a coolant temperature up to 130 ° C and pipes up to 10 cm.
Soldering at low temperatures is suitable for the installation of plumbing
The technology of joining copper products by soft soldering involves pre-cleaning the surfaces, applying flux paste with a brush and inserting elements into each other. Further, the connection point is heated by a gas burner to 200-250 degrees. The solder is applied to the edge of the joint.
It is important to remember when soldering, that the burner flame temperature can reach 1 thousand. degrees, therefore, it is enough to heat the elements 15-20 seconds. The flame must be moved constantly to evenly heat it. The control of the degree of heating is performed by the color of the flux. After darkening it is necessary to take solder.
After the introduction of soft solder in the soldering zone in contact with the heated copper pipe, the tin wire begins to melt and slide on the flux into the seam. Gradually the heated mass fills the space between the bell and the pipe.
Soldering
Soldering of copper pipes with their own hands using brazing is performed, if you plan to operate the system at higher temperatures 110 ° C. A higher temperature is required for the connection 700 degrees, therefore soldering is performed by gas-flame method.
Copper-phosphorus solder is available in the form of rods and is used for high-temperature soldering
pay attention! The technology of brazing involves the annealing of metal, which softens the copper.
The use of copper-phosphorus solder does not require flux. If you properly ensure uniform heating of the ends of the products, then it fills the gap. The connection is checked for readiness with a solder rod - it must melt.
The stages of soldering are as follows:
- The connecting unit is assembled and heated.
- Solder is introduced at the connection point of the bell and the pipe, which is softened by the burner.
- After the first coupling, the pipe is turned and the softened solder is wound on the next section of the joint.
The advantages of brazed copper pipe soldering technology are:
- good seam strength;
- the ability to reduce the width of the connection;
- applicability in systems, operating at high temperatures.
Since the correct soldering of copper pipes by brazing should eliminate overheating of products, which leads to gaps, then it is better to entrust the work to specialists.
Pipes, connected by brazing, used in heating systems
The main mistakes when soldering with your own hands
Before, how to solder copper pipes it is necessary to make sure that there are no defects on their surface, which often appear when cutting products. The reliability of the seam largely depends on the purity of the materials, used in the work. For pipes with a diameter 6-108 mm the width of the resulting connection can be 7-50 mm.
Importantly! If the copper pipe or solder is not heated enough, the tin or copper wire of the latter will not stick to the flux and will not soften.. This will leak at the junction.
Sometimes when applying the flux, some parts of the pipe are missed, which entails poor adhesion of the solder to the product. Overheating of the pipe leads to a similar result, in which the flux burns.
It is important to follow safety requirements when soldering, as the work involves the use of open fire, chemically active substances. Before, how to solder copper pipes, it is necessary to take care of personal protective equipment: gloves, glasses, etc.. d.
Properly organized and performed work on the connection of copper pipes will ensure a long service life of the pipeline.
