Reinforced-plastic pipes were among the first to appear as an alternative to replace traditional steel pipes. They are distinguished by simple installation technology, the ability to make complex highways with many turns, and a smooth surface. But what, in practice, are metal-plastic pipes for heating: reviews, installation, diameters, disadvantages and advantages will help to assess the relevance of their use.
Construction of metal-plastic pipes
Modern metal-plastic pipes for radiators have received their unique properties due to the use of polymer materials. For their manufacture, cross-linked polyethylene is used. But since it does not have the proper rigidity, an additional layer of aluminum foil is installed to give the pipes the necessary technical properties.
Manufacturing technology allows you to make different diameters of metal-plastic pipes for heating. For this, the extrusive method is used, the essence of which is to install the outer and inner layers of polyethylene on an aluminum base. Special glue is used as a binder. The final technical characteristics of metal-plastic heating pipes make it possible to operate them even with a high-temperature operating mode of the system. In addition, the following distinctive qualities of metal-plastic pipes should be noted:
- Low thermal conductivity. In fact, the line will not heat up very much, thereby reducing the heat losses of heating;
- Smooth surface helps to reduce the hydraulic resistance of the system;
- A small specific gravity makes it possible to install heating from metal-plastic pipes independently;
- Simple installation. However, special mechanical fittings must be used to connect individual piping sections. The quality will largely depend on the maintenance-free life of the heating.
Why are reviews of metal-plastic heating pipes not always positive? This is due to a large number of low-quality products on the market and a negligent attitude towards installation technology.
Before purchasing metal-plastic pipes, you should study the marking. It indicates the maximum exposure temperature and pressure limit values.
Special properties
Before considering the disadvantages of heating from metal-plastic pipes, you need to objectively evaluate their negative sides. They are also a consequence of the use of polymeric materials and aluminum foil as a rigid base. Although they do not corrode, some types of pipes use a polymer that degrades when exposed to direct sunlight.
In addition, it is necessary to take into account the difference in the thermal expansion of the polymers and the aluminum shell. When heated abruptly, the polyethylene layer will expand much faster than the foil. This will lead to delamination of the structure. Given this factor, the question arises - is it possible to use metal-plastic pipes for heating? Yes, but subject to the following operating conditions:
- Minimizing the manifestation of water hammer and sudden temperature jumps in heating;
- Concealed installation in those parts of the room where there is a high probability of sunlight hitting the highway;
- No surface tension, use of expansion loops to reduce the likelihood of rupture in the system.
To make a final decision, it is recommended that you familiarize yourself with the technical characteristics of metal-plastic heating pipes. To do this, you need to study the data in the table.
Despite the fact that during the installation of heating from metal-plastic pipes they can be bent, repeated deformation can lead to cracks or chips on the surface. This also needs to be taken into account during the execution of work.
As well as steel, metal-plastic pipes can collapse when exposed to negative temperatures due to the expansion of the liquid in them. In this case, it is necessary to insulate the line, as well as the installation of a heating cable.
Installation of metal-plastic pipes
Before purchasing metal-plastic pipes for radiators, you should choose the right diameter. When performing a standard calculation, it should be borne in mind that manufacturers indicate the outer size. It is necessary to subtract two wall thicknesses from it in order to obtain the value of the useful section. So, for a 20 mm diameter metal-plastic pipes for heating, the size of the inner cavity will be 16 mm.
Only after that you can proceed with the installation of pipelines. This will require at least a minimal set of tools - a pipe cutter, a pipe bend spring and a calibrator. The latter is a steel pin with standardized diameters.
Compression and press fittings
The main installation elements of the system are fittings for metal-plastic pipes for heating. They differ in the method of attachment to the nozzles, as well as in the material of manufacture. To create a quality pipeline, it is recommended to use stainless steel or brass products.
Fittings types:
- Compression... Fastening takes place by clamping the plane of the pipe between the fitting and the threaded union nut;
- Press fitting... A special crimping device is required for installation. Despite the high cost compared to compression fittings, press fittings are much more reliable and practical.
Among the disadvantages of heating made of metal-plastic pipes, one can single out the low reliability of fastening mounting assemblies. This is most often the case when using compression fittings, since sufficient force must be applied when tightening the union nut for a secure connection.
To install a reliable line, you will need not only good metal-plastic pipes for heating, and high-quality press fittings.
Crimping pliers can be rented. But in order to minimize the time of their use, all other tools and accessories must be prepared in advance.
Installation of metal-plastic pipes
In most cases, negative reviews about metal-plastic heating pipes are associated with non-compliance with installation rules. Therefore, it is required to study the recommendations of the manufacturers, as well as familiarize yourself with the installation instructions.
After it has been decided that it is possible to use metal-plastic pipes for heating systems, an installation diagram is drawn up. To do this, the location of the highways, their main nodes and components is drawn on the plan of the house. Then the calculation of the amount of required materials and components is performed. Step-by-step installation procedure:
- A piece of pipe is cut with scissors.
- Using a calibrator, the inlet is aligned for installation into the fitting.
- Having installed the press fitting, it is clamped. For this, crimping pliers are used.
For good metal-plastic pipes for heating, a spring pipe bender can be used.However, the minimum bending radius must be observed, depending on the pipe section.
It is recommended to purchase compression fittings for metal-plastic pipes for the heating system from the same manufacturer that makes the pipes.
Manufacturers of reinforced plastic pipes and their prices
One of the determining factors in the use of high-quality metal-plastic pipes for radiators is their manufacturer. Currently, there are several leading companies whose products meet quality standards. In addition, they provide clear instructions for installation, the choice of diameters of metal-plastic pipes for the heating system, as well as recommendations for their maintenance.
Henco
This Belgian brand is a leading manufacturer of metal-plastic pipes for heating systems. A distinctive feature of their products is the manufacturing method. For this, an aluminum pipe is formed by the method of spot laser welding. Then a layer of high density polyethylene is applied to the inner and outer surfaces. The result is a product with good technical characteristics, characteristic of high-quality metal-plastic heating pipes.
Pex
Thanks to the latest developments of Pex specialists, it became possible to install metal-plastic pipes in a heating system with high temperatures and pressures. Three-dimensional bonds are created by using high density polyethylene of low pressure. This guarantees the absence of delamination, and also increases the pressure threshold (up to 20 atm.) And temperature (up to +95).
In addition, a detailed manufacturing scheme does not allow oxygen to enter the coolant. The company is also engaged in the manufacture of fittings for metal-plastic pipes in heating systems.
| Name | price, rub. |
| Henco pipe, 16 mm | 30 |
| Henco pipe, 20 mm | 38 |
| Pex pipe, 16 mm | 108 |
| Pex pipe, 20 mm | 189 |
| Compression fitting, 20 mm | 82 |
| Crimp fitting, 20 mm | 172 |
It is not recommended to use reinforced-plastic pipes for centralized heating. The reason is possible water hammer and sudden temperature changes.
Testimonials
- I have heard a lot about the shortcomings of heating from metal-plastic pipes. However, at my own peril and risk, I decided to install them in a country house. I approached the matter thoroughly - I chose high-quality pipes and fittings. After a little training, I managed to mount everything myself. The system works for 2 years without complaints and breakdowns;
- At one time I heard about the good quality of metal-plastic pipes. Feedback from neighbors and friends influenced my choice. However, I ran into one problem - for concealed installation, it is necessary to install inspection hatches at the pipe joints. This slightly spoiled the appearance of the hidden heating;
- Having installed plastic pipes in my apartment, I regretted it. "Thank you" to the management company - constant pressure and temperature fluctuations led to pipe delamination. All lines had to be replaced.
You should also take into account the maintainability of metal-plastic pipes. The time to replace a specific area can be measured in minutes if the house has a minimum set of tools.
Video instructions for installing metal-plastic pipes:
