Polypropylene pipes are many times cheaper than copper, steel, and even metal-plastic pipes, but are not widespread all the same. For underfloor heating systems products marked PN25 are used, which are reinforced with peorized aluminum foil. Outer diameter from 21 to 78 mm, wall thickness 4-13 mm.
- low price;
- Ability to withstand the temperature of the coolant to 95 0 C at the optimum 55 0 C in the system of water underfloor heating;
- high durability, service life is at least 25 years.
- small bending radius, because of which it is often impossible to arrange the heating system of necessary efficiency. The minimum bend radius of polypropylene pipe. 8 diameters, which means that the pipe diameter, for example, 23 mm can be placed at a distance of 368 mm from each other, which may not be enough for a uniform heating. If the floor heating will be used as an additional source of heat, the use of polypropylene pipes is justified;
- terms of installation of polypropylene pipes. Installation is carried out at temperatures above 10 15 0 C, which is not always possible.
Advice on which cross-linked polyethylene pipes for underfloor heating and water supply are the best to choose
Flexibility, strength, durability, the ability to restore the shape after damage. these are the main, but far from the only, advantages of cross-linked polyethylene pipes. They confidently displace other types of pipes from the market, are actively used in the installation of underfloor heating, plumbing (hot and cold) and heating systems. Are they so universal?? Let’s dot all the i’s and try to figure out what pipes made of cross-linked polyethylene for underfloor heating and water supply are better to choose, what to pay attention to when buying and what manufacturers can be trusted.
If ordinary polyethylene (a polymer consisting of carbon atoms and hydrogen) is subjected to a particular action, some of the hydrogen atoms become separated, thus forming a new bond between the carbon molecules. The process of making these additional carbon bonds is called crosslinking. Polyethylene is affected by different substances and methods, so the degree of crosslinking may differ. The optimal rate is 65-85%.
Cross-linking makes it possible to improve properties of polyethylene: resistance to high temperatures increases, flexibility improves, wear resistance, the possibility of self-healing after mechanical stress appears. The cross-linking process was developed in 1968 by the Swedish chemist T. Engel, but underestimated his invention, considering it uncompetitive. His patent was bought by WIRSBO, which was the first company in the world to produce industrially cross-linked polyethylene (PEX) pipes, and the leader in this field to this day. On the domestic market, such products did not come into their own, but now they are very popular.
PEX-pipes normally consist of three layers: inside. cross-linked polyethylene, outside. oxygen barrier layer, they are glued together. You can also find 5-layer pipes on sale. They have another layer of adhesive and cross-linked polyethylene on top of the oxygen barrier layer.
How important is the right choice of pipes for underfloor heating
The water heating system, when the channels, through which the coolant circulates, are laid in the floor and the warm water circulates through them, at first glance is simple and understandable. Another thing is how to carry out installation of the pipeline on a prepared surface, competently arrange the water loop loops, provide a firm connection of pipes and respectively implement the connection of ready-made pipelines to the distribution equipment. Here are a lot of questions, to which you should look for the right answers and, accordingly, make competent engineering decisions.
Different tasks can be assigned to the floor heating in the home. Some prefer to use this type of heating in limited areas of the living space. Others put a large-scale task before the floor heating. heating the entire living area of the object. In this case, the floor heating pipe almost always plays a decisive role. The quality of the pipe, its strength and reliability are the main conditions for the effective operation of the heating system, especially when it comes to a large length of water circuits.
Currently, the market for consumables for heating systems is quite diverse. In the trade network you can see the consumables specifically designed for installation in the floor, differing in manufacturing method and composition. At first glance, only the cost of materials can be decisive in terms of choice, but in fact, the choice of water mains should be taken more carefully. There are a number of criteria on which to choose the consumable material for heating circuits of underfloor heating”.
Among the most important criteria, the following aspects should be noted:
- The cross-section of the water channel should not exceed 16 mm, taking into account the thickness of the screed;
- all consumables must be properly labeled, designed for use in low-temperature heating systems
- The ability of the pipe to withstand significant variations in operating pressure of the coolant in the system;
- technological resistance of the material to high temperatures;
- The resistance of the pipeline to mechanical influences and the response of the material to heat;
- ease of operation, including the implementation of routine and emergency repairs.
Important! When buying pipes, pay attention to the name of the company, the company-manufacturer. A well-known brand will guarantee you the quality of consumables, the reliability of the entire heating system.
In most cases today preference is given to work with plastic and polymeric pipes, which are based on cross-linked polyethylene. Such materials have already been tested in practice and serve as the basic elements of the pipelines of heating systems for more than one year and in different conditions.
If you want and have the financial capacity you can bet on copper pipes, but in this case the floor heating will be golden for you, literally. Underfloor heating, in which the pipe is the main working element, can have different lengths. To make a floor heating in the whole house, using expensive consumable material, a thankless task. Copper piping is suitable for the installation of water circuits in the bathroom or kitchen. To use copper piping for other purposes is a waste of money.
Each type of main water circuits used in underfloor heating systems has its own technological characteristics. Accordingly, the pipelines in this situation have different technical parameters and differ in terms of installation.
For reference: on a practical plane plastic products are most commonly used. Up to 90% of all water floor installations are made of plastic materials. The reason for such popularity and prevalence is that this consumable material is affordable and convenient from a practical point of view.
What are the options when choosing the optimal consumable material for underfloor heating? Let’s look more closely
Advantages and disadvantages of popular materials
All materials have their advantages and limitations. Consider the 4 types most suitable for warm floors pipes: copper, metal, polypropylene, and cross-linked polyethylene (PEX-pipes).
Option #1: copper is the universal material
Despite the development of technology and the emergence of many new materials, copper is still a relevant material. Its main advantage is durability. Bacteria do not grow on the surface of copper products. The material is resistant to corrosion, and pipes from it perfectly withstand high and low temperatures (from.100 to 250 degrees), mechanical influences.
Copper pipes for underfloor heating will not burst, melt, or crack. Due to the high technical and operational characteristics, the material is applicable in modern heating systems. If all the conditions recommended by the manufacturer are followed, the pipes are able to last up to half a century. It pays off the high initial costs.
For all the advantages and excellent performance qualities of copper pipes, they also have limitations. The material is sensitive to the hardness, acidity of water. If the heat transfer fluid in the system creates an acidic or alkaline environment, the service life of the pipe can be halved.
It is not recommended to drain too often from systems with these pipes. It is also undesirable to combine copper and steel, so as not to provoke negative electrochemical processes.
As for installation, the connections of copper pipes with special press-fittings are extremely durable. Their reliability sometimes exceeds the strength of the pipes themselves. Press machines. expensive equipment, so the installation will have to invite professionals, which creates an additional burden on the budget for the arrangement of the heating system.
Option #2: Metal plastic. reliably and inexpensively
A worthy alternative to copper. metal-plastic. This material is cheaper, so it is in high demand. Its advantages:
- durability (service life of metal plastic pipes, as well as copper ones, up to 50 years);
- Resistance to corrosive processes;
- environmental safety (polymers are environmentally friendly, they do not react with other materials and substances in the water)
- low weight (this is a significant advantage in comparison with copper pipes, the weight of which is significantly greater);
- Good soundproofing (water flowing through the pipes will make less noise).
Metal plastic pipes consist of several layers, and the inner surface is perfectly smooth, which prevents deposits on the walls of the products. The polymer material that covers the inside of the pipe, protects the entire structure from destruction and the negative effects of the coolant aluminum layer and adhesive compounds.
The quality of the adhesive layer is important. If the adhesive breaks down, the layers of the metal-plastic pipe begin to separate from each other, which leads to leaks at the joints. In order to understand how high quality compound is used you can heat the pipe up to 90. 100 degrees and see the result.
If the product remains unchanged in the cut, it means that the “right” materials and technologies were used in its manufacture. If you can see the layers, it is better to choose a different pipe manufacturer.
Metal plastic poorly tolerates the effects of open flame, but when installing a warm floor, this property of the material does not play a special role. And here’s what can really be a problem. poor quality connection. If the pipe diameter is greater than the inner diameter of fittings, then at the junction can grow lime deposits. This process is fraught with leaks.
When installing do not squeeze the pipe too tightly union nut, so as not to leave a cut that will later leak. For the laying of a warm floor of metal plastic pipes is better to invite professionals.
Option #3: Polypropylene pipes
Few people buy polypropylene pipes for underfloor heating, despite the obvious advantages. durability, environmental friendliness, low price. The demand for them is about the same as for copper. But while copper products are intimidating because of their price, polypropylene is inconvenient for installing a floor heating loop.
The bend radius of the pipe is 8-9 diameters. If you compare with products made of cross-linked polyethylene, in which this indicator is 5, the polypropylene loses.
The large bend radius makes installation difficult. If the pipe diameter is 16 mm (the allowed minimum), it can be laid with a spacing of about 128 mm. In most cases this is not enough to provide the necessary thermal capacity. The disadvantages of the material can be attributed to the restriction on the temperature of installation. not below 15 degrees Celsius, which is not always suitable for regions with harsh climatic conditions.
Variant #4: cross-linked polyethylene pipe
Polyethylene is a material made up of hydrocarbon molecules that are not bonded together. But the new technology makes it possible to bond the molecules through the interaction of hydrogen and carbon atoms. The result is a new material that is called cross-linked, or simply cross-linked polyethylene (PEX). It undergoes an additional high-pressure treatment, which creates new molecular bonds and increases its strength.
The production technology was invented about 40 years ago, but cross-linked polyethylene has become widely used and popular only in recent years. The material has unique properties, not typical for its “predecessor. It is durable, resistant to temperature differences, does not fray, does not crack and is not afraid of scratches. In many respects the quality of pipes made of this material depends on the degree and method of cross-linking.
Below is a video demonstrating the resistance of cross-linked polyethylene pipes to various influences:
For a warm floor, you should choose the material, the degree of cross-linking of which is 65-80%. The performance properties and durability of the material depend on it. The higher the indicator, the higher and the price of finished products, but these costs pay off. If the degree of cross-linking is low, the material may crack, lose resistance to external influences. The method of connecting the molecules is also important. There are only four of them: peroxide, silane, radiation and nitrogen.
The advantages of the material should include the following:
- Normal functionality over a wide temperature range. from 0 to 95 degrees Celsius.
- High melting and combustion temperature. The material begins to melt only when the temperature reaches 150 degrees. Combustion temperature. 400 degrees Celsius.
- “Molecular memory”. Cross-linked polyethylene pipe can be deformed, but after increasing the temperature it restores its original appearance and shape.
- Resistance to pressure fluctuations. PE-X pipes are well tolerant of pressure changes in heating systems of all types. They easily withstand 4-10 atmospheres (exact figures depend on the type of pipe and are listed in the technical documentation).
- Plasticity. The material is extremely plastic, thanks to which it does not break even if the product is bent several times in the same place.
- Chemical and biological stability. PEX pipes are not sensitive to aggressive chemicals. They are not exposed to corrosion, do not promote the growth of bacteria and fungi.
- Safety. Cross-linked polyethylene does not emit any harmful substances. Even in case of burning it decomposes into water and carbon dioxide, substances that are safe for humans.
Although PEX-pipes are recommended for use at 0-95 degrees, the material is capable of withstanding higher and lower temperatures. At.At 150 degrees it retains its strength and does not burst. However, operation under high loads can affect its durability.
The technology of installation of PEH-pipes is quite simple and does not require expensive equipment. Everyone can master it. We offer a master class on installation:
PEH-pipes are perfectly suitable for arrangement of underfloor heating, they can be used for radiator heating systems and hot water supply systems. The material does not tolerate prolonged exposure to direct sunlight, but for a warm floor is not principal.
Careful handling of the anti-diffusion protective layer of pipes during transport and installation. If damaged, oxygen can get into the structure of the material, which will adversely affect the durability of the pipe.
Today, manufacturers offer several types of pipes for warm water flooring. To make a reasonable choice, it is important to know what pipes are, their main technical characteristics, because it depends on how often you will have to open up the floor to make repairs.
- Copper. in recent years are losing popularity due to the availability of polymeric materials. Such pipes have a lot of advantages, but they can not be used if the water is too soft or, conversely, hard. And under the influence of any chemistry such material quickly breaks down.
- Metal-plastic. They are based on polymer, which provides pipes tightness and stiffness. The main advantages. low price and claimed service life of up to 50 years, but this material has a low thermal conductivity.
- Polypropylene pipes are successfully used for the assembly of heating systems, but they are not suitable for underfloor heating. Despite all the advantages, this type has serious drawbacks, including the lowest thermal conductivity of all.
- Corrugated. For their manufacture, thin sheets of stainless steel are used: they can be unannealed and annealed, the latter are more expensive, but better. These products have many advantages and very few disadvantages, but because of the high competition, corrugated pipes have not yet gained wide popularity.
- PEX pipes are products cross-linked from polyethylene, which are considered more durable and resistant to all types of corrosion. Many experts note that such pipes are best suited for a warm water floor.
On a side note!
In addition to the above types, there are pipes made of polyethylene PE-RT. They are slightly inferior to REX in quality, but their cost is 1.5-2 times cheaper.
Pipe for a warm floor: what kinds of pipes for warm floor systems are better, selection rules
The advantages of water systems can be talked about for a long time, but in this publication we will discuss a different kind of issue. We want to draw your attention to the fact that exactly the pipe for underfloor heating, properly selected and reliably assembled, is the key to obtaining a workable, efficient. and most importantly. trouble-free system. Which of them are ideal for this purpose and what are the features of this or that variant. about this
Underfloor heating: Understanding which pipes are best to use
The number of supporters of underfloor heating in the home is constantly increasing. it has proven to be highly effective and convenient. Indeed, correctly planned, competently assembled and well-established water underfloor heating system is distinguished by a high coefficient of efficiency. and consequently cost effectiveness, the most optimal microclimate created by it. with ascending hot air streams and a comfortable distribution of air temperature along the height. If you add to this the fact that this type of heating surface acts as a heat exchanger and badly fitted in the interior radiators do not, then the growing popularity of this type of room heating gets a complete logical explanation.
Accordingly, an increasing number of homeowners who are seriously contemplating a complete conversion to water underfloor heating. However, it should be noted that this is. quite difficult and very large-scale action. In addition to the complexities of the construction work, it is necessary to correctly calculate and select the heating equipment, distribution fittings, special devices and devices for monitoring, control and safety. And finally. A very important point is actually pipes for water underfloor heating. By these components of such a heating system should be of particular attention, due to the fact that the main load. and the thermal, and mechanical, falls precisely on them.
What should be the pipes for a warm water floor?
Anyone who thinks that you can buy any pipes for a “warm floor”. In the long run, it’s probably going to be very disappointing. The system of water underfloor heating is just the case, when its installation requires strictly defined materials, and the use of cheaper “counterparts” is either not welcome, or strictly prohibited.
ProWarm warm water underfloor heating kit installation. Pipe Staple method
First of all it is necessary to understand in detail the specific requirements for pipes in underfloor heating systems. These are dictated by the very special conditions in which they are used.
- Most of the existing floor heating schemes presuppose that the installed pipe circuits are filled with a monolithic concrete screed. This means that there is in principle no possibility of periodical inspection or maintenance work. It is clear that the screed is always poured with the expectation for many years to come. and the pipes must not lose their functionality and reliability throughout the expected considerable period of operation. In short, the durability of the pipe should be commensurate with the durability of building structures !
It concerns many operating parameters, but first of all. protection against corrosion processes, against internal overgrowth of its cavity, the stability of the manufacturing material. it should not be degraded by time, high temperatures and chemical composition of the coolant. Modern types of pipes are equipped with a special “oxygen barrier”, since the diffusion processes with the penetration of this active gas through the wall thickness of the material result in rapid ageing of heating circuits.
- Existing standards and regulations completely exclude the use of welded pipes (no matter whether with longitudinal or spiral joints) as closed “floor heating” circuits. Thus, all steel, galvanized and even stainless steel pipes that are widely used in water and gas supply or conventional heating systems are immediately cut off. The maximum that they can be used for is the transportation of the coolant from the boiler to the distribution cabinets (collectors).
Chief editor of the project Stroyday.ru. Engineer.
Well, on the other hand, such pipes VGS. it will be very expensive, and, in addition, will create absolutely unnecessary load on the floor. because the metal itself weighs a lot.
- Remember that any pipe joint that will be filled with screed is almost always a vulnerable point (with few exceptions). Any accident in the pipeline is unpleasant in itself, but in an open area it is not difficult to eliminate. But even a small leak that occurs in the circuit “warm floor”, can cause disastrous consequences. It is very difficult to notice it at once, and there is a high probability of flooding the lower floors, ruining the floors or even disabling the electrical system of the house.
In addition, any connection on a long stretch is a potential for clogging or infestation. Eliminate such a problem in the circuit “warm floor” will be extremely difficult!
So, ideally, the contour should not have fused sections. it should be made from a single piece of pipe. And this means, among other things, that the material has to be flexible, resistant to kinks and, in addition, be able to keep its curvilinear shape.
That in the Internet there are pictures of assembled floor heating with welding or soldering, with the use of bends or T-branches. this is not an example to follow. By and large. There are a lot of things laid out on the net that you do not have to look up.
- It will be appropriate to note at once that the purchased pipes. on the basis of the above, must be of sufficient length. In principle, the release form of most of the pipes used for such heating allows you to make the contours in one piece. Typically, for a pipe with a diameter of 16 m maximal length of one loop is chosen 50 ÷ 80 meters. Increasing the diameter allows you to lengthen the circuit. so, when using pipes Ø 25 m, the maximum length can even reach 100 ÷ 110 m. But do not get carried away in any case. the increase in hydraulic resistance with excessive elongation will result in no enough power of pumping equipment to make the coolant move through the pipes. This effect is called a “locked loop” and in order to avoid this, two (or more) loops are laid if a significant area needs to be heated.
- We can immediately mention the outer diameter of the circuit. Usually three varieties are used. 16 mm, 20 mm and, quite rarely, 25 mm.
Here it is important to remember that too narrowing means a lower heat output and an unnecessary load on the equipment. Too large a diameter always entails a considerable increase in the floor height and a heavier screed.
- The pipe must have a high strength. Its walls must successfully withstand both the external load, as a heavy concrete screed will have a serious impact, and directed from inside. peak pressure surges coolant in some heating systems can even reach 7 ÷ 10 bar.
- The pipe should be designed for operation in conditions of high temperatures. Although the systems “floor heating” is not used by the extra-high heat, however, to ensure the safety of the circuit in case of unforeseen circumstances, the pipe must be able to withstand temperatures up to 90 ÷ 95 ° C.
- Pipes used for floor heating circuits must have a high quality, almost perfectly smooth inner wall surface. This will ensure an acceptable value of hydraulic resistance and at most reduce the possible noise flowing through the pipes of the liquid. such sounds do not please everyone.
Now that you understand the basic requirements for underfloor heating pipes, you can see which materials fulfil these requirements.
Partly. This topic has already been discussed above. Apart from the cheapness of the material, this option is not any other positive. These pipes are available in straight and short (in terms of underfloor heating) sections, it is simply impossible to bend them with a small radius. Installation with welding is a very troublesome and unreliable. Yes, by the way, even if you manage to build such a system of floor heating, it can not be called efficient.
In a word, such an approach does not even deserve serious consideration.
About metal. or more precisely. We have already mentioned about the steel HTW pipes. they are simply unacceptable. However, metal to metal is not the same, and there are pipes that are ideal for underfloor heating.
This material has a full “bouquet” of all sorts of positive qualities. Copper pipes perfectly conduct and transmit heat. This material has excellent plasticity along with high mechanical strength. Copper. a very durable metal, thanks to its chemical characteristics can perfectly resist corrosion. over in modern pipes copper walls are additionally closed by a high-strength polymer film. service life of such products is counted in many decades.
The disadvantage. quite difficult installation, which requires special tools and steady skills to work with it. This greatly limits the possibility of independent creation of such a heating system. But perhaps. Even this is not the main thing. the cost of such pipelines, especially in comparison with polymeric, is extremely high, and accessible, alas, to very few.
Corrugated steel pipe
And this is probably the only type of pipe that is not prohibited to splice along the length of the heating circuit. so reliable are their fittings.
These pipes are made of stainless steel, they are easy to bend and hold their position well. The problems of corrosion resistance, high heat dissipation and mechanical strength are not even raised here. such pipes meet these requirements to the full extent. Their special additional protection is given by a special coating of high-quality high-pressure polyethylene.
Such pipelines, by the way, are actively used in technological lines in the chemical industry of many developed countries. and this says a lot. And yet they are not widely used in private residential construction. The main reasons. high prices, and perhaps even a lack of information from homeowners about these materials.
The form of release of corrugated stainless steel pipes. finished sections of different lengths or coils up to 30 or 50 meters long.
Here we must immediately make one important observation. If you read a variety of articles on water pipes used for heating circuits, you can see one common mistake. The authors divide the variety of flexible pipes into metal-plastic and made of cross-linked polyethylene. The reader from such a statement is often mistaken that in metal plastic products uses some conventional polyethylene, but in addition there is also cross-linked. Nothing of the kind! All the types of polyethylene used in modern production technologies have a certain degree of cross-linking.And to distinguish pipes will be better by other criteria. on technology of processing of polymer and on structure of the pipe itself.
What is cross-linked polyethylene PEX?
If you do not understand this at once, later on you can simply get confused with the concepts.
The well-known and so popular in the production of many household items polyethylene, for all its merits, is still not stable. It has a linear molecular structure, these “chains” are not connected at all and even under slight temperature influence ordinary polyethylene begins to “float” simply. Its use in products that are exposed to thermal stress, can not.
It is quite another matter if the above-mentioned molecular chains are “sewed”. that is to create numerous stable transverse bonds, to transform the linear structure into a three-dimensional one.The polymer does not lose any of its positive characteristics and gains stability. The more such intermolecular “bridges”, the higher the so-called degree of cross-linking (measured as a percentage) and the higher the quality and strength of the material.
Not only that, but cross-linked polyethylene has a very special property of “memory”. Products made of it, deforming to a certain extent due to mechanical, baric or thermal loads, always try to return to the initial shape that they once had when external impact stops completely or weakens. This is an extremely important feature in the production of pipes.
Cross-linked polyethylene has the conventional designation PEX. Cross-linking, that is the creation of transverse intermolecular bonds technologically is carried out in different ways.
- PEX. in this technology the formation of new bonds is caused by chemical treatment of the raw material with peroxide.Of all existing methods it gives the maximum degree of cross-linking (about 85%), polyethylene does not lose any elasticity, it is high-strength and has an expressed “memory. The disadvantage of the technology is its high complexity and high cost. However, the process is fully controlled, which allows to get the material with strictly defined qualities.
- PEX-b. this technology appeared later and was initially regarded as a simpler and cheaper alternative to PEX. Seemingly win-win and inexpensive, using water vapor, this crosslinking method still has not fully lived up to the expectations placed on it. The material is not so elastic, that is certainly will be limited by the radius of its bending. And at the same time the degree of cross-linking is only about 65%. It is extremely difficult to control the process during production, so often these pipes do not fully meet the stated characteristics. In several European countries PEX-b pipes are not allowed for use in heat distribution networks. There is one more interesting feature: the sluggish cross-linking process in the PECh-b polymer never stops. That is, over time, the material significantly changes its characteristics, becoming harder. shrinks, so often PEX-b pipes require regular tightening of joints, and metal-plastic pipes can delaminate.
- PEX-c. in this case the fusion process is caused by directional emission of electrons. Production of pipes made of such plastic is characterized by low cost, but the material is significantly inferior in quality characteristics, the same PEX-a. Nevertheless. this polymer is still used, for example in the manufacture of inexpensive metal plastic pipes.
- PEX-d is a technology, which is almost completely out of industrial application, in which intermolecular bonds are obtained by treating the raw material with specific nitrogenous compounds.
PEX cross-linked polyethylene pipes
Cross-linked polyethylene, which has undergone special processing, is very widely used for the production of various types of pipes, some of which are quite suitable for creating a water underfloor heating system, and some are even specifically designed for this purpose.
- For quite a long time masters have been actively using metal-plastic pipes PEX-Al-REX for the circuits of underfloor heating. It would seem that this material is suitable for such purposes like no other. It combines the advantages of both polymer and metal, can easily be bent into the desired curvilinear shape (with compliance with certain technologies) and holds the configuration assigned to it, perfectly conducts heat.
Here we need to pay special attention to the specific type of polymer used for the production of this pipe. As already mentioned, the best solution would be PEX pipes, although they are of course much more expensive.
With metal plastic pipes there is another important nuance. too much in the market of construction materials counterfeit, clear and poor-quality fakes, absolutely unknown producers who do not accompany their products with any documents and warranty obligations. Therefore. when buying a metal-base laminate should never be shy. you must be persistent and demand to see certificates of quality and compliance with existing standards.
Stroyday editor-in-chief.ru. Engineer.
But even good-quality PX-Al-PX pipes still have significant drawbacks. So, the heterogeneity of the wall material, and hence the coefficient of linear expansion of the layers. leads to their delamination over time. it is only a question of time. but this process is inevitable. The inner layer of PEX. forced narrowed (about 0.8 mm), and does not always cope with peak loads (any experienced plumber can tell you about the ruptures of metal-plastic pipes). In this case, a thin layer of foil (0.2 to 0.4 mm), even if it is perfectly welded, can not become an obstacle to the critical pressure.
Therefore, these pipes are not particularly recommended for use in screed “floor heating”. Probably safer and more reliable for these purposes would be to use a single-layer, purely polymer cross-linked polyethylene pipes.
For their manufacture are used PEX-a or PEX-b. The pipe wall can have a fully monolithic structure. or be fitted with a special EVON layer that serves as an oxygen barrier.
These pipes are very easy to arrange when installing “floor heating” circuits. They have good plasticity, which allows laying with minimal distance between adjacent loops.
All leading manufacturers necessarily equip their products with reliable connection fittings, which makes installation quite simple and straightforward.
When choosing any plastic pipes it is necessary to know at least a little bit about the system of their classification and marking. It may vary somewhat depending on the manufacturer, but still the basic principles remain the same. It is possible to consider with the help of concrete example.
1- in the first place there is usually a specific pipe model, its brand name.
external diameter of the tube and the total thickness of its walls.
specific European standards, indicating the possibility of using the pipe. In this case, an indication that the pipe is suitable even for drinking water.
applied technology of quality control of finished products.
cross-linking technology of polyethylene (according to Engel classification. described above).
correspondence of pipe parameters in terms of temperature and pressure with European standards DIN 16892/16893. Specific values for operating parameters and operating times can be found in the accompanying documentation in the form of a plate:
Sometimes these values are printed directly on the pipe body. e.g. “DIN 16892 PB 12/ 60 °C PB 11/ 70 °C PB 9/ 90 ° C”.
Information on date and time of production, line or machine number, etc.п.
In addition, it is usually followed by a marking of the pipe length. every meter. This simplifies both the realization of pipes and working with them directly during the laying.
It became possible with the development of technologies of controlled processes of spatial formation of macromolecules. Such polymers offer the widest range of possibilities. it is possible to create materials with precisely defined characteristics, making an accent on this or that property.
Complicated grid structure allows to dramatically increase resistance of the material to external and internal loads, to cracking at bends. At the same time the material, unlike PEX, remains thermoplastic, i.e. can be joined not only with mechanical adapters (fittings) but also with welding, which significantly increases the reliability of joints if required.
PE-RT polyethylene is being used on an increasing scale and there is a strong tendency that with time it will completely replace its “cross-linked colleague”. PEH. All this is due to a whole “bouquet” of their positive qualities:
- Production of PE-RT pipes is considerably simpler, since the material does not require cross-linking and all intermolecular connections are already present in the semi-finished product. By the way, this polyethylene can easily be recycled without loss of quality.
- Service life of such pipes is about 50 years and more.
- PE-RT pipes are not afraid of freezing. they can withstand several cycles of freezing water without losing the integrity of the walls.
- Unlike PEX, these pipes are easy to repair.
- The circuits made of these pipes do not squeak in the “warm floor” and are absolutely silent even at high intensity of water flow.
PE-RT polyethylene is used. as well as PEX, and for the manufacture of metal-plastic pipes, and for purely polymeric.
In both cases operational characteristics are considerably higher than with cross-linked analogues.
Pipes for underfloor heating: what is the best choice and why you should pay attention to heat-resistant polyethylene
When planning a water floor the question arises, what pipes are the best to choose for this purpose? This is a very responsible decision, because it will depend on it the effectiveness of the underfloor heating system.
Varieties of pipes differ in technology of production and purpose. Among the most common materials: copper, polyethylene (cross-linked or heat-resistant), metal-plastic and others. In this article we will tell you what pipes are better to pay attention to among the possible options, and what to choose for a warm water floor.
What pipes are used for underfloor heating? Why choose metal-plastic and polypropylene more often?
Piping is the main working part of the heating system “warm water floors”, so on what consumable material will be used, t.е. What kind of pipe will go into the work, the main attention is paid during installation. For the construction of heating floors is important quality consumable material, high technological characteristics of the pipe. Due to the rapid increase in the popularity of water heating, the technology of producing equipment and consumables for heating, have stepped far forward.
In the market of thermal, heating equipment are the following types of pipes:
Any of the options voiced cope well with the tasks entrusted to it. The only point that distinguishes all options from each other, the cost and performance. About copper pipes, and about the corrugated channel for the water circuit we will talk another time. These materials are not popular at the household level due to their high cost.
Now let’s look at a different issue. What is better for your floor, metal or polypropylene? What is the difference between these most common materials?
Metal plastic is one of those materials with which you can work, having any qualifications. Pipelines made of metal plastic pipes are easy enough to install, repair or replace damaged sections.
On a side note: metal plastic pipes are very convenient for laying water pipelines in autonomous heating systems. The radiator method of heating is mainly installed using metal-plastic pipes.
Correctly laid water circuit makes the floor of metal-plastic pipes reliable, practical and durable. Especially appealing is the fact that the water heating circuits of metal plastic, solid and hermetic, have a high degree of reliability. Trunks are connected to a distributive comb of a collector by means of fittings which more often have a metal basis. Joining of metal plastic pipe fragments with adapters is carried out through threaded joints.
For reference: According to experts, if you do not put certain skills and dexterity, threaded connections in contact with metal-plastic pipes can leak.
The water floor pipe made of metal-plastic, connected with the help of press fittings, have greater reliability. As a result of crimping a strong and tight connection is created.
Polypropylene pipes are also connected by fittings. The difference is that the connection is carried out by heating the edge of the pipe with special equipment. By means of a soldering iron polypropylene is firmly connected with fittings, making the connection monolithic and reliable.
In order to make a choice in favor of metal plastic or give preference to polypropylene materials, it is necessary to answer the question. What is better than polyethylene or metal-plastic, how much the products are practical in the operation of warm water floors, and what will be the cost of installation of a water heating loop? The question of cost is often a decisive point. The difficulties of installation will become known in the process of work. Not the least important role in terms of choice are the design features of both materials. What is the difference between the consumables?
For water supply and hot water heating systems both are perfectly suited. Due to the low cost of materials, you can lay long enough pipelines, providing water and heat for the entire house. For a warm floor, the use of metal-plastic pipes entails certain risks. Laying the channel heating circuit in the concrete screed or under the tile, in case of a leak, repair work will be quite extensive and difficult. Polypropylene pipes are more reliable in this aspect. Given the coefficient of thermal expansion, properly installed polypropylene heating circuits will last a long time.