Capillary soldering

Soldering is a process used to firmly join parts together. This process involves using solder, which acts as a bonding agent, and flux. Flux helps remove the oxide film and protect against atmospheric influences. One type of soldering is capillary soldering. This soldering method is widely used in joining copper pipes. It allows for a very efficient and durable connection. capillary soldering This indicates a very small gap between the pipes being joined, typically 0.1–0.3 mm. This creates surface tension. When solder enters the gap, it rises and fills the empty space.

Capillary soldering technology

 Capillary soldering technology   It involves a simple technological process. However, it is crucial to follow the sequence of operations precisely:

To begin, special fittings are selected that match the pipe being connected. The preliminary connection should have a gap of 0.1 - 0.3 mm;

• Burrs are removed from the inside and outside of the pipe. The connecting surface of the pipe and fitting is also cleaned of oxides;
• Apply a thin layer of flux to the pipe and fitting surfaces to be joined. Then firmly press the two parts together. Rotating movements ensure even distribution of the flux over the surface. Wipe off excess flux with a dry cloth.
• Using a gas torch, begin heating the pipes. This is best done from below, as the heat rises and gradually heats all parts of the pipe and fitting. Move the torch over the surface being joined to ensure complete heating. It's important not to overheat the pipe to avoid burning the flux. This will prevent the solder from filling the joint gap.
• After heating, move the torch to the fitting neck and apply solder to the joint. Capillary action draws the solder into the neck and fills the joint gap. For better penetration, press the solder lightly against the pipe and keep the torch slightly away from the solder. This creates a suction effect. You can then repeat the soldering process, slightly overlapping the solder to ensure a strong joint.
• After soldering, allow the joint to cool naturally. Artificial cooling, such as with water, can weaken the joint. Wipe off any flux residue with a damp cloth from the outside and rinse the inside.

Such  capillary soldering technology  Allows you to create a high-strength connection without significant expense. There are high-temperature and low-temperature soldering methods.

High-temperature method

This method is used when pipes are exposed to high temperatures or require exceptional strength. During soldering, temperatures reach 750 degrees Celsius. Therefore, a highly skilled installer is essential to prevent pipe ruptures. Special solid fluxes are used for this type of soldering. High-temperature soldering is used:

• when heating is installed, including solar heating;
• in gas supply;
• in refrigeration equipment, heat exchange.

Low-temperature method

This method is used when the pipe operating temperature does not exceed 130 degrees Celsius. The joints are heated to 200–250 degrees Celsius. Tin-silver solder or similar alloys are used for this purpose. It is used in domestic hot and cold water supply systems.