Many private houses are heated using water heated floor systems. This factor is explained by the efficiency of this type of heating. The coolant circulating through the pipeline laid under the floor has a much lower temperature than in radiators. This means that much less energy resources are spent on heating it.
Warm floors do not spoil the interior of the premises at all, since they are hidden from the eyes of others by the finishing coating. And the air, heated over the entire surface of the floor, is always directed upward, creating a favorable microclimate and increasing the level of comfort.
Ideally, the use of such heating systems should be envisaged at the stage of building a house. Otherwise, you will need to carry out calculations and large-scale work that requires certain skills and craftsmanship. In addition to choosing high-quality heating and pumping equipment, it is necessary to pay close attention to the choice of consumables, the main of which is the pipe.
It is a mistake to believe that any pipe can be laid in a concrete screed. Increased demands are placed on this element of the system, since the service life of the heated water floor and the quality of operation of the entire system will depend on it.
And although this consumable material is presented in a huge assortment on the construction market, not each of them meets all quality and safety requirements.
Which pipe is suitable for laying the water circuit and will not only extend its service life, but also save money? What do the designations PEX and PE-RT mean? What are the advantages of PERT polyethylene, which recently appeared on the Russian market?
Requirements for pipes
In most cases, the contours of a water-heated floor are filled with a heavy concrete screed, closed with a finishing finish. Even after removing tiles or removing part of the laminate, carry out visual inspection system for leaks or any other malfunctions will be impossible.
Therefore, any pipe that is part of a water-heated floor system must meet strict requirements stipulated by the special conditions of its operation.
The main element of water heated floor systems has a standard diameter, which can correspond to the following values:
It should be noted that when using consumables a smaller diameter reduces heat transfer, which leads to a reduction in the distance between the loops of the circuit and, accordingly, to an increase in material consumption. In addition, the small diameter of the pipe leads to overloads of the pumping equipment. It is also inadvisable to use pipes of too large a diameter, since in this case the thickness of the concrete screed will increase and, as a result, the load on the floor.
DIY water heated floor
What materials are pipes for heated floors made from?
So what material should be preferred when installing water-based floor heating systems? And here you should not rely on sellers’ assurances that all their goods comply necessary requirements. Such carelessness can lead to problems that arise already at the installation stage of the systems.
Several materials are used in the production of pipes for heated floors.
- Polypropylene. This option is the most budget-friendly. And this is perhaps his only positive quality. It will not be possible to mount a circuit from a single piece of pipe, since they are sold in small meters. This material is not highly plastic, so laying the contour is possible only if big step between the loops. And most importantly, polypropylene has a very low heat transfer coefficient, so the system will be ineffective.
- Metal. Metal pipes can be made of copper and corrugated steel. These materials are of high quality and durability. But their significant drawback is high price, inaccessible to most of the population.
- Polyethylene (PEX and PE-RT). This also includes metal-plastic. In the production of all varieties, different types of polyethylene are used, and each pipe has a special structure and is processed using different technologies. These materials are distinguished by ease of installation, resistance to mechanical and temperature influences, as well as affordable cost.
PEX pipes
First of all, you need to understand what the term “cross-linked polyethylene” or PEX means. Many household items are made from polyethylene. However, in its original form, this material is sensitive to high temperatures.
And it’s all because of the structure of the material, the molecules of which are not connected to each other in any way. This drawback is eliminated by using a special treatment of polyethylene, which allows the molecules to be “cross-linked”, due to which the polyethylene becomes stable and does not melt under the influence of high temperatures.
Pipes for heated floors
As a result of such processing, the PEX pipe acquires another positive quality, which is the ability to return to its original shape. That is, if during the operation of water heated floor systems the pipe experiences overload or is subject to mechanical stress that changes its position, after reducing the intensity of the load it will take on its originally specified shape.
Cross-linking of polyethylene is carried out using different technologies, designated as follows:
It should be noted that when arranging water circuits, PEX-a pipe is most often used. The next two varieties are used much less frequently due to their lower quality. And PEX-d pipes in last years and are not used at all.
PE-RT polyethylene pipes
The designation on the pipe “PE-RT” means that it is made of polyethylene with increased heat resistance. This concept does not mean that stitching technology was used in relation to it, since unique material PE-RT already has everything necessary qualities. A distinctive feature of the PERT pipe is the possibility of connection in the circuit using welding or fittings. Regardless of the type of work performed, PERT does not lose its strength and ductility.
PERT polyethylene is also used in the production of metal-plastic pipes, distinctive feature which is the presence of an internal aluminum layer. If a PE-RT polyethylene pipe is produced without an internal metal layer, it is protected from oxygen penetration by other means, for example, by an airtight layer of OXYDEX.
A water heated floor mounted from a PERT pipe has higher performance characteristics. This material, unlike PEX, has increased elasticity and the ability to withstand heat up to 124.7°C. Considering the lower cost of production of PE-RT polyethylene, the installation of heated floor systems from PE-RT pipes is somewhat cheaper, while meeting all the requirements for this method heating
Video: Warm water floor
Today, Uponor pipes made of cross-linked polyethylene are widely used in the organization of cold and hot water supply systems, as well as heating, including floor heating, and snow melting systems. They form a special class among other polymer pipes. Uponor pipes are the result of 35 developments aimed at creating particularly strong and reliable pipes.
REC PIPES UPONOR
Uponor pipes are produced using PE-Xa technology - under high pressure and temperature, as well as exposure to organic peroxide, polyethylene macromolecules are cross-linked to form Carbon-Carbon cross-links. In this case, a strong and elastic three-dimensional structure is formed, which provides the products with high resistance to thermal and mechanical stress.
Uponor pipe applications
Uponor PE-Xa pipes can restore their original shape, as they have a “thermal memory” effect. In addition, the pipes are coated with an anti-diffusion coating, which prevents the risk of corrosion. Pipes have the following advantages:
- heat resistance;
- excellent elasticity;
- durable service life of at least 50 years;
- resistance to ultraviolet radiation;
- resistance to aggressive environments;
- resistance to mechanical deformation.
Thanks to the advantages of PE-Xa pipe storm drain Uponor will last a very long time.
Benefits of Uponor pipes
The Santekhkomplekt company offers a wide range of pipes of various diameters, supplied in coils, as well as fittings for them. Uponor products are impeccable quality and reliability.
Thanks to special system fittings (Quick&Easy), you will receive a system completely ready for installation. Installation using press fittings allows you to achieve amazing reliability of connections.
Application of cross-linked polyethylene pipes
XLPE pipes PEX-a are presented by the Finnish concern Uponor. PEX-a pipes have a wide range of applications, the evalPEX line is intended for systems radiator heating. The advantages of this type of pipe are high resistance to temperatures in the range from -100°C to +110°C, molecular shape memory, low thermal conductivity, simplicity and ease of installation, high elasticity, silent operation, resistance to chemicals.
The safety of cross-linked polyethylene pipes is confirmed by an international eco-certificate. The pipes are designed for a pressure of 6 bar. Our catalog contains EVAL PEX-a pipes with a diameter of 16, 20, 25, 32, 75, 90 mm in coils of various sizes.
Advantages of polyethylene pipes
Polyethylene pipes have many advantages, in particular:
- resistance to chemical attack;
- excellent elasticity and molecular shape memory;
- low thermal conductivity;
- resistance to high and low temperatures;
- long service life;
- environmental safety;
- ease of installation and light weight.
Thanks to these advantages, cross-linked polyethylene pipes are widely used in heating systems. At the Santekhkomplekt company you can order high-quality pipes made in Europe (Finland).
Threaded fittings
Fittings are one of the the most important nodes supply of water, coolant, etc., since they often have to withstand the heaviest load. The Santekhkomplekt company offers a wide range of brass threaded fittings, as well as PPSU and PE-Xa connecting parts for cross-linked polyethylene pipes. Labor-intensive process Installation with Uponor fittings is simple, fast and convenient.
Connections made from high-strength PPSU plastic, which has proven itself in heating and water supply systems, are resistant to high temperatures(up to +170°C), high impact resistance and resistance to aggressive environments. Along with other plastics, PPSU is not subject to corrosion, and in terms of strength and reliability characteristics it is comparable to metal. Plus, polyphenyl sulfone is UV resistant and not prone to deposits. The result is highly reliable and tight connections, the cost of which is lower than similar metal products.
Uponor offers threaded fittings with a diameter of 16-25 mm and connecting parts with larger diameters - 50-63 mm. The company's use of the most advanced materials guarantees reliable operation and extended service life of both individual pipeline parts and the entire system as a whole.
Pipe Thermotech Thermosystem®(old name Thermotech >MIDI< Composite) является модернизированным вариантом труб PE-RT, полностью изготовленной из материала Dowlex 2344 (тип 1) и 2388 (тип 2) (PE-RT, trademark Dowlex is owned by DOW Chemical Corp.) with a large number of bonds between molecules, with an oxygen barrier (EVOH) hidden inside the pipe between layers of polyethylene. Because All layers are polymers, then as a result of sequential connection of layers, a pipe is formed as a single whole, stable under conditions of temperature and pressure fluctuations, with a small linear elongation, resistant to mechanical stress.
Let's decipher the abbreviation PE-RT - PolyEthylene of Raised Temperature resistance - polyethylene of increased temperature resistance - the secret lies in large quantities carbon bonds in molecules. The side chains of the linear Standard Polyethylene (PE) molecule are formed by a combination of butene molecules. Two carbon atoms are used to connect the main chains to each other, so the probability of intertwining is low. The side chains of the linear PE-RT polyethylene molecule increase the number of connecting Carbon atoms to 6, while the degree of intertwining is much higher. If the source material for PEX - Polyethylene, with the same monomer content, is not “cross-linked”, then it will provide much less strength under prolonged exposure to pressure.
Warm floor pipe Thermotech Thermosystem®– has an anti-diffusion layer OXYDEX (EVOH polyethylene), which prevents the penetration of oxygen and an anti-creaking layer, which form a single whole with the pipe.
Anti-diffusion layer OXYDEХ: During pipe production, PE-RT is applied to the surface of the “main” pipe thin layer modified polyethylene, 0.1 mm thick. This is followed by the same layer of EVOH (ethyl vinyl hydroxide) plastic. Previously, this anti-diffusion layer was applied to outside pipes. Over time, some manufacturers and Thermotech pipes, incl. They began to apply another protective layer of polyethylene on it.
New polymer pipes from Thermotech - ThermoSystem pipes made of PE-RT type II polyethylene - are more flexible and more reliable compared to the old ThermoSystem pipes (12, 17 and 20 mm) due to the placement of an anti-diffusion layer on the inner surface of the pipe with a protective layer polyethylene. The oxygen barrier is protected from mechanical damage the entire thickness of the pipe wall
The EVOH layer acts as a diffusion barrier for oxygen, and the polyethylene layer increases the adhesion between the pipe and the diffusion barrier. The barrier is tightly glued to the pipe, making bends of small radii possible without the formation of folds. Oxygen-tightness of pipes Thermotech complies with the DIN 4726 standard (Deutsches Institut fur Normung), and is less than 0.1 g/m2. for 24 hours at 40 °C. OXYDEX layer in pipes Thermotech reliably protected from mechanical damage protective layer polyethylene. The melting point of the anti-diffusion layer is 180° C. These properties allow the use of such pipes at operating temperatures of the carrier up to 95°, and in short-term modes – up to 110° C, that is, mainly in hot water supply and heating systems, heated floors.
Oxygen penetrating the system does not cause any harm to the pipes themselves; it only reacts with the metal parts of the system, causing accelerated corrosion of heating boilers, pumps, radiators, shut-off and control valves and other metal equipment. This process is especially accelerated when using pipes in systems with elevated temperatures, i.e. in heating systems (especially radiator systems). Unfortunately, it is not included in SNiP permissible value oxygen penetration in plastic pipe systems. Therefore, in reality, pipes without a diffusion layer are often used, which after 5 years leads to the failure of the steel elements of the system. To prevent this from happening, it is necessary to use only pipes in heating systems that meet the requirements of the German standard DIN 4726. It should be noted that today only a few companies can offer pipes that meet the requirements of this standard.
This pipe can withstand high pressure. The lifespan of PERT pipes is determined by nomograms depending on the temperature and pressure of the working medium (as well as all other polymer pipes). According to Russian certification, PE-RT pipes are classified as type “t” (heavy), i.e. withstanding pressure of 20 kgf/cm2.
The THERMOTECH brand produces 5-layer unreinforced pipes for heating and water supply systems:
- Thermotech Thermosystem PE-RT I diameters 8x1, 12x2 mm, 17x2 mm, 26x3 mm
- Thermotech MultiPipe PE-RT II diameters 16x2, 26x3,
- Thermotech Thermosystem PE-RT II diameter 20x2, 32x3 mm
Advantages of Thermotech pipe
Thermotech = reliable + easy to install + inexpensive!
Extreme flexibility and strength without the use of a crosslinker. The secret lies in the large number of carbon bonds in the molecules. To understand the difference, answer the question: what kind of shoes do you prefer to buy - with edging sewn to the sole (analogous to molecular cross-linking of polyethylene) or with a glued sole (analogous to chemical cross-linking of polyethylene or glued plastics)?
The service life of the pipe is over 50 years. It requires virtually no maintenance during operation, which further facilitates the work of public utilities.
Able to withstand high pressures and temperatures. The service life of PERT pipes is determined by nomograms (see appendix) depending on the temperature and pressure of the working medium. According to Russian certification, PE-RT pipes are classified as type “t” (heavy), i.e. withstand pressure 20 kgf/cm2
Polyethylene pipes are 5–7 times lighter than steel pipes. Pipes are produced seamlessly in standard coils 12 * 2.0 mm (1000 m), 16 * 2.0 mm (750 m), 20 * 2.0 mm (650 m), 25 * 2.3 mm (350 m), 32 *3.0 mm (50 m). This significantly reduces transportation costs and makes the work of installers easier.
The temperature linear expansion of PE-RT pipes is several times less than that of standard PEX pipes. When the temperature changes by 50°C, the linear elongation of PE-RT pipes is only 0.3%, and when the temperature changes by 90°C – 0.7%. When cooled, the pipe completely returns to its original shape.
Docking polyethylene pipes much cheaper, simpler and less time consuming. The pipes are connected using brass compression fittings and takes seconds. The entire installer's tool consists of pruning shears and wrench. Therefore, even a non-specialist can change or install the plumbing himself.
No squeaking in underfloor water heating systems.
Due to the low surface roughness (0.125 microns), the pipes are not subject to overgrowing, therefore require virtually no maintenance during operation and are silent at almost any flow rate.
Frost-resistant and able to withstand several freeze-thaw cycles (for example, water).
It has high maintainability. Multiple joining and undocking of the fitting is allowed, while the pipe at the joint retains its properties.
Can be used for transportation food products, aggressive liquids and gases.
Fully meet the requirements of modern industry for the aesthetics of work and operation of pipelines.
Warranty periods: shelf life 3 years, service life 7 years.
The pipe is resistant to chemicals and mechanical wear.
Foreign certification.
The pipe was tested at SKZ (Suddeutsches Kunststoff Zentrum). According to SKZ tests, the service life of PERT pipe is 490 years with a safety factor of 2.5.
According to the TUV (Technisher Uberwaschungs - veren Bayern) conclusion, a pipe with an OXYDEX layer is not subject to oxygen diffusion (does not allow air to pass through).
The production has an international quality certificate ISO 9002.
Russian certification.
GOSSTROY OF RUSSIA No. 0130837*. Application in heating systems.
HYGIENE CERTIFICATES. According to test results at Polymertest LLC, the service life of the MIDI pipe is more than 100 years, depending on operating conditions.
ROSTSTANDARD. Application in DHW and cold water systems.
Certified for heating systems with operating coolant temperatures up to 95°, at peaks up to 110° C (no worse than any other polymer pipes), pressure up to 20 kgf/cm2 (!).
Pipes Thermotech Thermosystem® are manufactured in Germany by the HPG concern to order from Thermotech (Sweden).
DEVELOPER and MANUFACTURER of PE-RT compound Dowlex 2344 - "The Dow Chemical Company"
Materials and articles from "The Dow Chemical Company" in attachments:
- PE-RT, new class polyethylene for hot water pipes
- PE-RT, a new class of polyethylenes for industrial pipes
How do underfloor heating pipes behave at sub-zero temperatures? We do not object to the use of pipes in conditions with low temperatures. Moreover, well-known facilities with PE-RT pipes have been operated without problems for years in arenas with artificial ice in Europe.
PERT pipes maintain high strength even at temperatures down to -40°C.
The DOWLEX 2344E material, compared to other polymers, has a higher thermal conductivity at negative temperatures (2-3 times higher), which means the power of refrigeration units can be reduced.
Thermotech pipes have a mirror-like internal surface, they have a very low roughness (0.125 microns, class 10), this is less than that of PEX pipes and significantly less than that of any metal-plastic pipes. The fact is that in metal-plastic pipes the main load is borne by the aluminum layer and therefore the polymer layers in such pipes are of worse quality than in plastic pipes. Reducing hydraulic losses in Thermotech pipes will reduce the power of circulation pumps.
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A lot of objects have been made. For a very long time there were no competitive offers at all! No complaints.
Differences between pipes >>>
» PE-RT pipes - characteristics of new pipes for plumbing
The popularity of PEX series plumbing pipes made of cross-linked polyethylene has suddenly been called into question. And it was done by none other than the manufacturer himself. American company Legend recognized the undeniable popularity of PEX, but at the same time noted the negative properties of this product. The PEX pipe series suffered from a serious operational drawback - residual traces of chemicals in the water. Plus, disposal and recycling promises a lot of difficulties. Therefore new plumbing pipes PE-RT, based on bimodal polyethylene, is confidently replacing the PEX series from the leading position in the plumbing market.
PE-RT series for plumbing
The American company Legend began producing innovative plumbing products that are functionally and technically more advanced back in 2015.
Polyethylene plumbing hoses for heating and hot water supply, marked with the “HyperPure PE-RT” brand, increase the efficiency and performance of the hydraulic system.
The number of supporters of home heating according to the “” principle is constantly increasing - it has proven its high efficiency and convenience. Indeed, a properly planned, competently installed and well-functioning water floor heating system is distinguished by high efficiency, and therefore cost-effectiveness, the most optimal the microclimate created by it - with rising currents of warm air and a comfortable distribution of air temperature along the height. If we add to this the fact that with such heating the floor surface acts as a heat exchanger, and there are simply no radiators that do not fit well into the interior, then the growing popularity of this type of room heating receives a complete logical explanation.
Accordingly, the number of home owners who are seriously considering a complete transition to water-based floor heating is also increasing. However, it should be noted that this is a rather complex and very large-scale undertaking. In addition to the difficulties with conducting construction work, it is necessary to correctly calculate and select heating equipment, distribution fittings, special instruments and monitoring, control and safety devices. And finally, a very important point is the pipes themselves for the warm water floor. These components of such a heating system must be Special attention, due to the fact that the main load - both thermal and mechanical - falls on them.
What should the pipes for a warm water floor be like?
This material has a full “bouquet” of all kinds of positive qualities. Copper pipes conduct and transfer heat well. This material has excellent ductility along with high mechanical strength. Copper is a very durable metal due to its chemical properties. capable of special features Excellent corrosion resistance. Moreover, in modern pipes the copper walls are also covered with an additional high-strength polymer film - service life similar products are calculated over many decades.
Copper pipe - practically no drawbacks, except for a very high price and installation difficulties Lack - Enough complex installation which requires special tools and stable skills to work with it. This greatly limits the possibility self-creation such a heating system. But, probably, this is not even the main thing - the cost of such pipelines, especially in comparison with polymer ones, is extremely high, and, alas, is affordable to very few.
Corrugated Steel Pipe
And this is probably the only one types of pipes that It is not prohibited to splice along the length of the heating circuit - their fitting connections are considered so reliable.
Such pipes are made from of stainless steel, they bend easily and retain their given position well. The problems of corrosion resistance, high heat transfer and mechanical strength are not even raised here - such pipes fully meet these requirements. They are given special additional protection by a special coating made of high-quality high-density polyethylene.
Such pipelines, by the way, are actively used on production lines in the chemical industry of many developed countries - and this says a lot. And yet they are not yet widely used in private residential construction. The main reasons are high prices and, perhaps, even a lack of information among home owners about such materials.
The production form of corrugated stainless pipes is ready-made sections of various lengths or coils up to 30 or 50 meters long.
Polyethylene-based pipes
Here it is necessary to immediately make one important note. If you read the variety of articles on water pipes used for heating circuits, you will notice one common mistake. The authors divide the variety of flexible pipes into metal-plastic and made from cross-linked polyethylene. From such a presentation, the reader often gets the misconception that metal-plastic products use some kind of ordinary polyethylene, and in addition to this, there is also cross-linked polyethylene. Nothing like this! All types of polyethylene used in modern production technologies have one degree or another of cross-linking. And it will be better to distinguish between pipes using other criteria - based on the polymer processing technology and the structure of the pipe itself.
What is cross-linked polyethylene PEX?
If you don’t figure this out right away, you can simply get confused in the concepts in the future.
Polyethylene, known to everyone and so popular in the production of many household items, for all its advantages, is still not stable. It has a pronounced linear molecular structure, these “chains” are in no way connected to each other, and even with a slight temperature effect, ordinary polyethylene simply begins to “float”. It cannot be used in products that are subject to thermal stress.
It’s a different matter if the mentioned molecular chains are “stitched” - that is, stable numerous cross-links are created, transforming the linear structure into a three-dimensional one. In this case, the polymer does not lose any of its positive characteristics, and plus it gains stability. The more such intermolecular “bridges” there are, the higher the so-called degree of cross-linking (measured as a percentage), and the better and stronger the resulting material.
Moreover, cross-linked polyethylene has a very unique “memory” property. Products made from it, to a certain extent deformed from mechanical, baric or thermal loads, always tend to return to their original shape once given to them after external influence stops completely or weakens. This is extremely important feature specifically for pipe production.
Cross-linked polyethylene has the accepted designation PEX. Cross-linking, that is, the creation of transverse intermolecular bonds, is technologically carried out in different ways.
- PEX-a - with this technology, the formation of new bonds is caused by chemical treatment of raw materials with peroxide. Of all existing methods– it is this that gives the maximum degree of cross-linking (about 85%), polyethylene does not lose any elasticity, it turns out to be highly durable and with a pronounced “memory”. The disadvantage of the technology is its rather high complexity and high cost. However, the process is completely controlled, which allows us to obtain material with strictly specified qualities.
- PEX-b - this technology appeared later and was initially considered as a simpler and cheaper alternative to PEX-a. It would seem that this cross-linking technique, which was a win-win and cheap method using water vapor, did not fully justify the hopes placed on it. The material turns out to be not so elastic, that is, there will certainly be restrictions on its bending radius. And at the same time, the degree of crosslinking is only about 65%. During production, it is extremely difficult to control the process, so often such pipes do not fully comply with the declared characteristics. In a number European countries PEX-b pipes are not allowed for use in heat distribution networks. There is another interesting feature - the sluggish process of stitching in PEX-b polymer never stops. That is, over time, the material significantly changes its characteristics, becomes stiffer, and shrinks, so PEX-b pipelines often require regular tightening of connections, and metal-plastic pipes can delaminate.
- PEX-s - in this case, the sewing process is caused by directed electron radiation. The production of pipes from such plastic is characterized by low cost, but the material, it must be said, is significantly inferior in quality characteristics to the same PEX. Nevertheless, such a polymer is still used, for example, in the manufacture of inexpensive metal-plastic pipes.
- PEX-d – almost completely removed from industrial applications a technology in which intermolecular bonds were obtained by treating raw materials with special nitrogen compounds.
PEX cross-linked polyethylene pipes
Past special treatment, cross-linked polyethylene is very widely used for the production various types pipes, some of which are quite suitable for creating, and some are even specifically designed for these purposes.
- For quite some time now, craftsmen have been actively using metal-plastic pipes PEX-Al-PEX for the contours of heated floors. It would seem that such a material is suitable for such purposes like no other. It combines the advantages of both polymer and metal, easily bends into the desired curved shape (subject to certain technologies) and holds the configuration given to it, and conducts heat well.
This is where you need to pay special attention to the specific type of polymer used to produce this pipe. As already stated, optimal solution there will be tons of PEX-made rubies, although they are, of course, much more expensive.
There is another one with metal-plastic pipes important nuance– too many on the market building materials counterfeit, obvious and low-quality fakes, absolutely unknown manufacturers who do not accompany their products with any documents or guarantees. Therefore, when purchasing metal plastic, you should never be shy - you must be persistent and demand that the products be presented with certificates of quality and compliance with existing standards.
But even high-quality PEX-Al-PEX pipes still have significant drawbacks. Thus, the heterogeneity of the wall material, and hence the coefficient of linear expansion of the layers, leads to their delamination over time. The only question is time - but this process is inevitable. Inner layer PEX is forcedly narrowed (to about 0.8 mm), and does not always cope with peak loads (any experienced plumber can tell you about ruptures of metal-plastic pipes). At the same time, a thin layer of foil (from 0.2 to 0.4 mm), even with perfect welding, cannot become a barrier to critical pressure.
For their manufacture, PEX-a or PEX-b are used. The pipe wall can have a completely monolithic structure, or be equipped with a special layer of EVON¸ which serves as an oxygen barrier.
These pipes are very convenient to lay out when installing “warm floor” circuits. They have good ductility, which allows installation with a minimum step between adjacent loops.
All leading manufacturers necessarily equip their products with reliable connecting fittings, which makes installation quite simple and an understandable activity.
When choosing any polymer pipes, you need to understand at least a little about the system of their classification and labeling. It may vary slightly depending on the manufacturer, but still basic principles are saved. You can consider it with a specific example.
1- in the first place, the specific model of the pipe and its brand are usually indicated.
2 – outer diameter of the pipe and total thickness of its walls.
3 – special European standards indicating the possibility of using pipes. In this case, this is an indication that the pipe is suitable even for drinking water.
4 – applied technology for quality control of finished products.
5 – polyethylene cross-linking technology (in accordance with Engel classification, which was described above).
6 – compliance of pipe parameters for operating temperature and pressure with European standards DIN 16892/16893. Specific values of operating parameters and service life can be indicated in the accompanying documentation in the form of a plate:
It also happens that these values are applied directly to the pipe body - for example "DIN 16892 PB 12/60 °C PB 11/70 °C PB 9/90 °C".
7—information about the date and time of production, line or machine number, etc.
In addition, this is usually followed by a pipe length mark - every meter. This simplifies both the implementation of pipes and the work with them directly during installation.
Video: useful information about cross-linked polyethylene pipes
Polyethylene pipes RE- RT
A technological breakthrough can probably be considered the emergence of a completely new type of polyethylene in the production of pipes - PE-RT(short for " Polyethylene oof Raised Temperature resistance"—polyethylene with increased heat resistance). By and large, it is not a crosslinking product, and even the initial raw material, granulate, already has the necessary qualities - numerous and stable intermolecular bonds.
This became possible with the development of technologies for controlled processes of spatial formation of macromolecules. Such polymers open up a wide range of possibilities - you can create materials with precisely specified characteristics, focusing on one or another property.
The complex mesh structure of the lattice allows you to dramatically increase the resistance of the material to external and internal loads, to cracking during bending. And at the same time, the material, unlike PEX, remains thermoplastic, that is, it can be connected not only using mechanical adapters (fittings), but also using welding, which significantly increases the reliability of joints if necessary.
Polyethylene PE-RT are being used on an ever wider scale, and there is a strong tendency that over time it will completely displace its “stitched brother” - PEX. All this is thanks to a whole “bouquet” of their positive qualities:
- Pipe production PE-RT– much simpler, the material does not require cross-linking, all intermolecular bonds are already incorporated in the semi-finished product. By the way, this polyethylene can be easily recycled without loss of quality.
- The service life of such pipes is about 50 years or more.
- Pipes PE-RT are not afraid of freezing - they are able to withstand several cycles of complete freezing of water without losing the integrity of the walls.
- Unlike PEX, such pipes are easy to repair.
- The contours of these pipes do not creak in a “warm floor” and are absolutely silent even with high intensity water flow.
Polyethylene is used PE-RT, just like PEX, both for the production of metal-plastic pipes and for purely polymer ones.
In both cases, the performance characteristics are significantly higher than using cross-linked analogues.
When manufacturing a polymer pipe without a metal insert, manufacturers often use their own proprietary developments to ensure oxygen impermeability walls For example, this could be an airtight OXYDEX layer, or a special anti-diffusion EVON barrier.
The main operational characteristics of such pipes are given as an example in the following table:
| Index | 16 × 2 mm | 20 × 2 mm |
|---|---|---|
| Volume (l/linear m) | 0.113 | 0.201 |
| Weight (kg/linear m) | 0,071 | 0.127 |
| Minimum bending radius – 5d (mm) | 60 | 100 |
| Temperature (°C) | 20 | 20 |
| Pressure (bar) | 20 | 20 |
| Service life (years) | more than 50 | more than 50 |
| Temperature (°C) | 75 | 75 |
| Pressure (bar) | 10 | 10 |
| Service life (years) | more than 50 | more than 50 |
| Temperature (°C) | 95 | 95 |
| Pressure (bar) | 6 | 6 |
| Service life (years) | more than 50 | more than 50 |
| Ultimate pressure (bar) | 6 | 4.5 |
| at temperature (°C) | 110 | 110 |
| Ultimate pressure (bar) | 11 | 10 |
| at temperature (°C) | 90 | 90 |
| Linear elongation coefficient max at t=95°С (1/°С) | 1.8 1E-4 | 8.2 1E-5 |
| Thermal conductivity coefficient (W/K m) | 0.41 | |
| Internal surface roughness (µm) | 0.125 (Class 10) | |
| Design strength of material (Mpa) | 6.3 |
To summarize what has been said, it can be noted that polyethylene pipes PE-RT today they are probably the material that best meets the requirements of a “warm floor” system, while remaining in the sector of reasonable affordability.
How much will it cost to buy pipes?
It depends, Firstly, on the length of the heating system circuits. – you can find out by reading the corresponding publication on our portal.
When making calculations, one should not forget about the sections from the floor to the distribution manifold, taking into account the connecting margin of at least 500 mm at each end.
The cost of pipes may depend on the manufacturer, the specific model, and the region where the material is purchased. The products of well-known European companies – “Uponor”, “Rehau”, “Kermi”, “Henco”, “Oventrop” and others - enjoy the greatest authority and, accordingly, demand. For example, the table shows several models of pipes suitable for “warm floors”. Prices are indicative, typical for the central regions of Russia:
| Manufacturer, brand | Diameter, mm | Brief technical specifications | Coil length | Price per 1 linear meter |
|---|---|---|---|---|
| Uponor PEXа evalPEX Q&E 16 x 2.0 | 16 | Cross-linked polyethylene, wall 2 mm, t max – up to 95 degrees, (short-term heating up to 110) | 50 – 240 m | 90 rub |
| Uponor PEXа evalPEX Q&E 20 x 2.0, | 20 | -//- | 50 – 120 m | 114 |
| REHAU "Rautitan stabil" | 16 | Metal plastic, PE-Xc/AI/PE wall 2.6 mm | 100 | 105 |
| REHAU "Rautitan stabil" | 20 | Metal plastic, PE-Xа–AL–PE wall 2.9 mm | 100 | 150 |
| REHAU "Rautitan flex" | 16 | Cross-linked polyethylene RAU-PE-Xa, wall 2.2 mm | 100 | 105 |
| Kermi MKV xnet 16 x 2.0 | 16 | Metal-plastic, PE-Xс–AL–PE–Xс | 100 | 55 |
| REHAU "Rautitan Pink" | 16 | Cross-linked polyethylene RAU-PE-Xa, wall 2.2 mm, t swing - up to 90 degrees | 120 | 64 |
| Wieland cuprotherm CTX | 20 | Copper pipe in a plastic sheath, wall 2 mm | 50 | 240 |
| FLEXSY-20 | 20 | Corrugated annealed stainless steel pipe with polymer coating, wall 2 mm | up to 50 | 175 |
| BioPipe PERT 16x2.0 | 16 | Monolayer, t max – up to 100 degrees, pressure – up to 6 bar. | 240 m | 35 |
| Thermotech MultiPipe PE-RT II, 16*2 mm | 16 | Five-layer with diffuse barrier | 240 m | 85 |
The table deliberately does not indicate the most inexpensive types of pipes, from unknown or very dubious manufacturers. It is worth thinking carefully before buying cheap, untrustworthy products, since a water-heated floor system poured with a concrete screed should not cause any reason for concern for the home owner.
And finally, a video assessing pipes for a “warm floor” system from a specialist.
Prices for water pipes
Water pipes
Video: which pipes are better for “warm floors”?