In the assembly of heating circuits, copper pipes are not used very often. Their cost does not attract owners of private houses and apartment owners too much. However, if the installation is done correctly, then the high cost of the copper pipeline will pay off for many years of operation without repair costs.
We will talk about how to correctly select copper pipes for heating. In our article, we present the features of marking, describe how to connect the components. Independent owners will find instructions for assembling heating systems.
Types of Copper Tubes
There are two large groups of copper pipes: thick-walled and thin-walled. Pipes included in the first group have increased strength characteristics. They are produced in a seamless and welded manner.
Pipes of the second group have found application in shipbuilding and automotive, aviation, i.e. where communication systems must be lightweight and more robust. The cross section of copper pipes can be either round, or rectangular, square. In heating systems, profile pipes, as a rule, are not used.
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Copper pipes - the oldest type of pipe used in the assembly of pipelines for at least a millennium. They have practically no shortcomings, except for one - a considerable price
Copper pipes are used mainly in private low-rise construction. This is not cheap, one might say elitist material. They do not rust, rarely overgrow with internal sediment, extremely rarely flow
Copper pipes without destruction and deformation withstand pressure from 210 to 300 MPa. Moreover, their wall thickness is much less than that of steel counterparts, which means that the working clearance is greater
Copper communications work well in a wide temperature range: from -100 ° C to + 250 ° C. Even after thawing, they do not crack; at ultrahigh temperatures for other pipes, they do not melt
The flexibility and ductility of copper pipes makes it possible to construct from them pipelines for water-heated floors of any complexity, using a minimum of fittings and welded assemblies
Without a doubt, it is better to build a copper pipeline if the boiler with a copper heat exchanger serves the heating system
In the construction of copper pipelines, fittings are used, installed by crimp, compression and welded methods
Copper pipes are suitable for both open and hidden installation. Their service life often exceeds the operational life of the house
Copper pipe heating system
Copper pipe in a wooden house
Durable, durable communications
Connecting copper pipes to the radiator
Copper coil of water floor heating
Use with copper heat exchanger boiler
Connecting elements for copper pipes
Open heating system wiring diagram
For thick-walled pipes, the cross section is round, the wall thickness varies in the range of 0.8 - 10 mm. Different types of copper are used in their production: M1, Mp3, Mp1 and others. The digital index here indicates the degree of purity of the alloy. This does not affect the characteristics of the pipe itself. Thin-walled pipes have a wall thickness of 0.15 to 0.7 mm.
The state standard allows the measurement of copper pipes both in the metric system and in inches. In the designation of the first indicate the outer diameter, and the second - the inner. The pipes used in the installation of heating systems are marked in inches.
Here, all existing diameters of copper pipes are tabulated. Using these data, you can easily pick up accessories for the installation of the heating main
To perform internal heat exchangers, copper pipes with a diameter of up to 10 mm are used. Such a diameter, combined with highly efficient energy transfer, guarantees the maximum return on the functioning of this device.
Pipes 3/8 inch or more are used in the heating systems themselves. They provide efficient heating with low energy consumption.
Specifics of decoding of markings
The normative document defining the standards of copper pipes used for heating is GOST 617-2006. It stipulates the requirements for the brand of copper, the range of sections, wall thickness.
Copper products have their own marking, decoding which you can find out the characteristics of the pipe:
- Preparation method. It is indicated by the letters D and G. The first indicates that the pipe is cold-drawn. They are made from 1.5 to 6 m long. The second - the product is made by pressing. According to regulatory requirements, manufactured from 1 to 6 m long.
- The geometry of the cross section of the pipe. КР - section in the form of a circle.
- Precision manufacturing. Letters N and P. N - normal, P - increased.
- condition. M, P, T, L, R, Ch. These indices indicate a soft, semi-solid, hard, soft pipe with increased ductility, semi-solid pipe with increased strength, and hard pipe with increased strength, respectively.
- Length. ND - the index indicates that the pipe is non-dimensional, MD - indicates a measured pipe, KD - multiple measured, BT - in bays.
- Special conditions. Y - the length of the pipe in the bays is increased, B - the pipe has increased accuracy with respect to length, K - the pipe has increased accuracy in curvature.
For illustrative purposes, an example: suppose a marking in the form of a DKRNM 32 x 3 x 3000 M2 B is present on the pipe.
It can be decrypted as follows: a cold-deformed pipe with a round shape of normal accuracy, made of soft copper, having an outside cross section of 32 mm and a wall thickness of 3 mm. It is a measured length of 3000 mm, made from copper grade M2.
For heating, solid pipes are mainly used. Pipes in soft execution are expedient to use for the device of a heat-insulated floor where it is required to carry out a large number of turns
In the manufacturing process, copper pipes can be heat treated and then called annealed. When this step is excluded from the process, unannealed pipes are output.
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Pipes for the assembly of copper communications
Soft grades of copper pipes for communications
Semi-solid pipes for heating systems
Hard pipe assembly systems
All three types of copper pipes are suitable for arranging private houses, since the pressure in the heating circuits in them never exceeds the values indicated even for soft varieties.
The marking is as follows:
Being able to decipher the marking of pipes correctly, you will never purchase products intended for the installation of water pipes for a heating device
In the first case, the products gain plasticity, but lose their resistance to deformation. Pipes made without annealing have increased strength characteristics, but it is almost impossible to bend them.
The advantages of copper pipelines
All the advantages of copper pipes stem from the unique properties of this material, the products of which:
- Harmless and possess bactericidal qualities.
- Long do not age and do not lose their performance.
- Resistant to corrosion and ultraviolet. They work in a wide temperature range - from -200 to + 350 ° C.
- Immune to chlorine in tap water.
- They have high thermal conductivity, which increases the efficiency of the heating system.
- On the surface of copper pipes having a small roughness coefficient, no plaque is formed.
- Resistant to freezing. The pipeline does not collapse and does not lose its original characteristics, being frozen up to four times.
- They are able to maintain strength properties under the influence of pressure reaching 200 - 400 atmospheres.
- Resistant to vibration.
- They have a wide assortment range.
- 100% recyclable.
From the choice in favor of copper pipes for heating, many often stop both the high price of the pipeline itself and consumables.
The heating device from copper pipes is accompanied by the purchase of a variety of fasteners, connectors, fittings. The cost of all this is about 30% of the amount spent on pipes
Copper pipes are lightweight, they can be cut, bent and soldered. The most popular method of connecting a copper pipeline is soldering at high temperatures using silver-bronze solder. Faster installation is carried out using fittings.
Features of the choice for heating
Copper has its own individual characteristics, which impose both operational and technical limitations on their use. These points must be taken into account when installing the heating system.
Although copper pipes are known for their strength, they calmly withstand pressure surges, temperature drops, and repeated freezing, but they do not withstand mechanical stresses. Therefore, when laying the pipeline, shock protection should be provided.
A heat carrier such as water contains sand and other suspended particles. The result of their impact on soft copper is erosion. To avoid this phenomenon, it is necessary to include water treatment filters in the system.
The hardness of the water also affects the pipe life. The value of this indicator in milligrams below the value of 1.42 and above 3.1 significantly reduces their longevity. This is explained by the fact that chlorine dissolved in water reacts with an oxide film present on the pipe walls. The result is strong protective armor.
If the water hardness indicators do not meet the standards, this protective layer begins to collapse, then due to the presence of chlorine its regeneration occurs. If this process is repeated many times, copper resources are depleted.
Connecting the pipeline by soldering, it is necessary to exclude overheating, which negatively affects the strength. The flux that remains after soldering must be removed, as it can cause corrosion.
If you want to bend the copper pipe, you need to use a special tool for this. An unsuccessfully bent pipe can be corrected once, and then it remains only to remove the wrinkled area.
The ideal option is to install a heating system from the same pipes. If for some reason this does not work out, you need to use transition fittings - brass or bronze. Adapters made of other materials cannot provide electrochemical compatibility.
Copper pipes can be mounted even at very low temperatures, therefore such a heating system is a rational solution to the problem in regions where cold weather is normal
In order for pipes from other materials not to corrode under the influence of copper, a certain sequence of connection of such a combined pipeline with respect to the water flow vector is needed. Copper pipes must be mounted after elements made of other metals.
If you plan to install a heating system with laying pipes inside the wall, you need to use copper pipes in a plastic shell. It will fulfill not only the role of thermal insulation, but also protect the metal from destruction. Copper pipes and stray currents are detrimental.
Copper Pipe Docking
The connection of copper pipes is carried out by different methods. The most popular are 2 approaches to this issue: soldering and assembly using compression or press fittings. In general, one-piece and conditionally detachable connections are made.
In such a pipeline, there are practically no additional parts, except for the elements with which devices are connected to the pipeline. To install the system in this way, special devices are needed. Without proper qualifications, joining or soldering is difficult.
The use of fittings facilitates installation, requires less effort and reduces the assembly time of the pipeline. The connection of this type can be detachable and one-piece.
A detachable connection is obtained using self-locking, threaded and compression fittings. This method complicates the design, the connections must be checked periodically, but even a person without experience can perform the installation.
One-piece crimp connections
In order to dock copper pipes, manufacturers produce special fittings that vary in purpose, installation methods, and the material from which they were made.
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Crimp fittings
Crimping with tongs
Press connections in the heating system
Pipeline assembly at the facility
Based on the purpose, the following fittings exist:
- Bends, which are needed for joining pipes of different sections with corner joints.
- Crosses, which are also called tees and are used in the installation of branches from the main pipeline.
- Couplings used on straight routes for bundling copper pipes of different diameters.
- Collet fittings that are used when installing automation in the heating system.
For copper pipes, crimp fittings of copper, brass, and bronze are most often chosen. Brass fittings are sometimes nickel plated to give them extra strength.
Brass elements for connecting copper pipes are cheaper than copper, and are not inferior in strength to stainless steel. All fittings, regardless of manufacturer, are regulated by international standards and are interchangeable.
One-piece - this is a connection by pressing. Since copper is very ductile, installation is carried out using press fittings and crimp sleeves. In terms of tightness and strength, such a connection can be compared with soldering, and it is more durable than compression.
Visually, press fittings are similar to capillary solder connectors. The difference is in the presence of an o-ring made of high quality polymer.
In order to connect the pipes by means of a press fitting, they are cut into pieces of the desired length, the ends are cleaned, calibrated. After, the ends are pushed into the connector and clamps the joint using special pliers
When installing a heating system using copper pipes of small and medium diameters, low-temperature soldering is mainly used. Welding is used when pipes of large cross section are used. The pressing method is in demand when installing underfloor heating.
Compression fittings
For the installation of compression fittings there is no need for either special equipment or the use of open flame. All you need is a wrench, a calibrator mandrel, a cutter. To make these connections, collet or crimp fittings are required.
There are 2 types of compression fittings - some having an index A connect hard and semi-solid pipes, others marked with an index B connect soft and semi-solid pipes. The fitting includes a body, a crimping nut, a copper crimping ring, which flattens when pressure is applied to it.
Thus, the connection becomes airtight and resistant to vibration fatigue. The connection is carried out in the same way as when installing press fittings.
The abutting ends of the segments of copper pipes are cleaned, the geometry of the section is checked with a caliber, a crimp ring is put on, the ends of the pipe are inserted into the fitting until they stop. The nut is first tightened manually, and when the pipe becomes stationary relative to the connector, take the tool and carry out the pull-up.
Crimp fittings of type A are sometimes used not only for connecting pipes made of solid copper, but also for products made of soft copper. In the latter case, the support sleeve is inserted inside to avoid deformation of the pipe ends
The connection strength of copper pipes with fittings is weakened by temperature instability and pressure surges. After a certain time, the seals wear. To oversee this weak link in the system, the connectors must be positioned so that they have easy access.
Do not thread copper pipes. To connect them with threaded parts, special adapters are produced. Their design provides for a socket connecting the fitting to the pipe by crimping or soldering and threading from the opposite side.
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Fitting for forming a collet connection
Compression fitting components
Union nut and o-ring
Installation of shutoff and control valves
Emergencies in a heating system assembled from copper pipes are extremely rare, but if this happens, then pipes of equal diameter are temporarily connected by shrink couplings. You should be aware that all types of connections do not reduce the strength characteristics of the heating system.
Fittings increase the thickness of the pipe walls, and in the place of welding, over time, the connection becomes more durable, exceeding the strength of the pipeline itself.
Copper Solder Fittings
Such fittings are called capillary. Connection with their help provides for the presence of solder. The key is to choose the right fitting for the copper pipe. Its internal section should be 0.1 - 0.15 mm larger than the outer diameter of the pipe.
The technology is simple:
- cut the required pipe size;
- protect;
- chamfer with a chamfer - outside and inside;
- clean the pipe, as well as the inside of the fitting, again until a matte sheen appears;
- Coat the end of the pipe. Designed for placement in the fitting and the fitting itself inside with a special paste;
- insert the pipe into the connecting element, rotate it;
- wipe the protruding paste, otherwise it will come into contact with the metal;
- heating the compound using a gas burner or building hair dryer;
- bring the solder to the gap after the flux begins to melt and lighten;
- finish the process when the solder flows over the entire surface and evenly fills the gap.
In order not to spend extra solder, you can wrap a pipe with it even before soldering, and cut off the excess. Upon completion of the brazing of the copper pipes, the compound is allowed to cool at room temperature.
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Soldering copper pipes in a pipeline assembly
Copper pipes suitable for soldering
Low temperature soldering lamp
Brazed gas burners
Initially soldered fitting
Application of flux before soldering
The use of rod solder
The color of the pipe to determine the degree of heating
After installing the entire heating system, do it flushing using hot water. This procedure will help to clean the remaining paste from the pipes. Docking places are inspected from the outside of the pipeline. If somewhere there is a flux or solder, it is removed with a damp cloth.
The next article on their technical characteristics and specifics of marking will familiarize you with the guidelines for choosing copper pipes for water supply.
Video # 1. On the pros and cons of copper pipes:
Video # 2. Copper pipe training:
If we compare copper pipes with polymer and steel pipes, the former are distinguished by higher quality and reliability. Despite the high cost, they find their consumer and their popularity is growing.
The main thing is to choose the right supplies, and if you do it yourself, the heating system from copper pipes will cost much less.
Want to talk about how you bought copper pipes for the construction of the heating circuit? Do you know the technological nuances of assembling copper pipelines that are not covered in the article? Please write comments in the block below, post a photo on the topic of the article, ask questions.