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Completely copper plumbing or heating is rarely done today, but still it is done. If you count on the number of years during which copper can serve, it turns out not only inexpensive, but very cheap. Nevertheless, the material itself is not the cheapest, but you can save on installation – soldering copper pipes is not the most difficult task in the world. There are certain rules and features, knowing which you can achieve a high-quality connection.
Types of copper pipes and their use
There are two types of copper pipes on the market: annealed and non-annealed. Annealed after formation, they undergo additional heat treatment – they are heated to 600-700 ° C. This procedure returns to the material elasticity, which is lost during molding. Therefore, annealed pipes are more expensive, but also more flexible – they can even withstand freezing water. The disadvantages of these products include lower strength – it decreases due to heating.
Unannealed copper pipes are stronger, but practically do not bend. When distributing plumbing or heating, they are cut into pieces, and all taps are made using the appropriate fittings.
There are copper pipes with different wall thicknesses, sold annealed in coils of 25 and 50 meters, non-annealed runs of 3 meters. If we talk about the purity of the material, then according to GOST 859-2001, at least 99% copper must be present in the products.
Connection methods
Most often, copper pipes are connected by soldering and a set of special shaped elements – fittings. There are also fittings for pressure testing. They have grooves with a rubber sealing ring installed. They are crimped with special pliers. But this technology is used infrequently – soldering is considered more reliable.
There are two technologies for soldering copper pipes using different solders:
- Low temperature – with soft solder. Just our case. This type of connection is used when laying water pipes and heating systems with a medium temperature of up to 110°C. Low temperature is a relative term. In the soldering zone, materials are heated up to 250-300°C.
- High temperature hard soldering. This type of connection is used in networks with high pressure and temperature of the transported medium. In household networks – rarely (although no one forbids), more often in industrial networks.
What type of soldering copper pipes to use is your choice. Both types are suitable for both plumbing and heating. But high-temperature requires a professional torch, while soft solder can be melted even with a blowtorch or an inexpensive hand torch with a small disposable gas canister. For connecting copper pipes of small diameter, more is not required.
Types of Brazed Copper Fittings
In general, there are more than two dozen different shaped elements for copper pipes – fittings, but three types are most often used:
- couplings – for connecting two pipes;
- corners – for turning;
- tees – to create branches in the pipeline.
Couplings for soldering copper pipes
The number of used fittings can be minimized – copper can be bent, which will reduce the number of required corners. Also, if desired, you can do without couplings: one end of the pipes can be expanded (using an expander) so that a pipe enters it and there is a gap for solder to get there (about 0,2 mm). When creating an extension, the pipes should overlap by at least 5 mm, but more is better.
What is difficult to do without is without tees. There is equipment for inserting a branch – a beader, but it belongs to the professional and costs a lot. So in this case it is cheaper and easier to get by with tees.
There are two types of fittings – conventional, with flares, which provide the required clearance for solder flow. The solder is fed into the welding zone manually. There are fittings with built-in solder. Then a groove is formed on the socket, into which, during production, a piece of solder is installed, which makes the soldering process easier – you just need to heat the welding zone, but it leads to an increase in the cost of fittings.
Consumables and tools
In addition to pipes and fittings, you will also need a torch, solder and flux – for the soldering itself. And also a pipe bender and a few related little things for processing before starting work.
Solder and flux
Soldering copper pipes of any type occurs with the help of flux and solder. Solder is an alloy usually based on tin with a certain melting point, but necessarily lower than that of copper. It is fed into the soldering zone, heated to a liquid state and flows into the joint. After cooling, it provides a tight and durable connection.
For amateur soldering of copper pipes with your own hands, tin-based solders with the addition of silver, bismuth, antimony, and copper are suitable. Compounds with the addition of silver are considered the best, but they are the most expensive, optimal ones with a copper additive. There is also with the addition of lead, but they should not be used in plumbing. All these types of solder provide good seam quality and easy soldering.
Soft solder is sold in small reels, hard solder is sold in packs, cut into pieces.
Before soldering, the joint is treated with flux. A flux is a liquid or pasty agent that causes molten solder to flow into a joint. There is nothing special to choose here: any flux for copper will do. Also, you will need a small brush to apply the flux. Better – with natural bristles.
Burner
To work with soft solder, you can buy a small hand torch with a disposable gas bottle. These cylinders are attached to the handle, have a volume of 200 ml. Despite the small size, the flame temperature is from 1100°C and higher, which is more than enough to melt soft solder.
What you should pay attention to is the presence of piezo ignition. This function is not superfluous in any way – it will be easier to work. A valve is located on the handle of a manual gas burner. It regulates the length of the flame (the intensity of the gas supply). The same valve shuts off the gas if the burner needs to be extinguished. Safety is provided by a non-return valve, which, in the absence of a flame, will shut off the gas supply.
Some models have a flame deflector. It does not allow the flame to dissipate, creating a higher temperature in the soldering zone. Thanks to this, the burner with a reflector allows you to work in the most inconvenient places.
When working in household and semi-professional models, you need to be careful – do not overheat the unit so that the plastic does not melt. Therefore, it is not worth doing a lot of soldering at a time – it is better to let the equipment cool down and prepare the next connection at this time.
Related materials
To cut copper pipes, you need a pipe cutter or a hacksaw with a metal blade. The cut must be strictly vertical, which provides a pipe cutter. And to guarantee an even cut with a hacksaw, you can use an ordinary carpentry miter box.
When preparing pipes, they must be cleaned. To do this, there are special metal brushes and brushes (for cleaning the inner surface), but you can get by with sandpaper with medium and fine grains.
To remove burrs from cuts, there are bevelers. The pipe they have worked out fits better into the fitting – its socket is only a fraction of a millimeter larger than the outer diameter. So the slightest deviation leads to difficulties. But, in principle, everything can be eliminated with sandpaper. It will only take more time.
It is also advisable to have protective goggles and gloves. Most home crafters neglect these safety measures, but burns are very unpleasant. These are all the materials and tools needed for soldering copper pipes.
Copper soldering step by step
Soldering copper pipes begins with the preparation of the connection. The reliability of the connection depends on the quality of the preparation, so devote enough time and effort to this process.
Connection preparation
As already mentioned, the cut of the pipe should be strictly vertical, without burrs, the pipe should not be jammed, the edge should be even and smooth. If there are even slight deviations, we take a beveler or sandpaper and bring the cut to the ideal.
Next, take the fitting, insert the pipe into it. the part that goes into the socket needs to be cleaned. We take out the pipe and remove the upper oxidized layer from this part of the pipe with sandpaper. Then we carry out the same operation with the inner surface of the socket.
Flux application
The flux is applied to the entire cleaned surface – outside the pipe and inside the fitting. There are no difficulties here – the composition is evenly distributed with a brush.
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The processed pipeline fragments are inserted into one another and fixed. If there is an assistant, he can hold the parts motionless. If not, you’ll have to figure it out on your own. Next, the burner is ignited, the flame is directed to the junction. The flame temperature is from a thousand degrees and above, and the junction must be heated to 250-300 ° C, and this takes 15-25 seconds. At the same time, you can focus on the color of the flux – as soon as it darkens, it’s time to introduce solder.
To ensure uniform heating, direct the burner flame in the middle of the joint. Then the entire welding zone warms up more evenly.
Solder is injected at the junction – where the fitting and pipe are connected. As it heats up, it begins to melt, spreads and fills the gap between the elements. You can apply it only half the length – when melted, it will flow into the rest of the connection. Actually, that’s all – the soldering of copper pipes is finished. All other connections do the same.
When using hard solder, everything is almost the same, only other burners are used – gas-flame ones, and in the process of soldering it is necessary to turn the pipe, winding the softened solder onto the pipe.