Polyethylene pipes for heating: features and installation. Polyethylene pipes for heating private properties XLPE pipe for heating

Low-temperature heating lines are becoming very popular. Thanks to modern heating systems and devices, housing can be warmed up at a coolant temperature of 80 0 C.

Therefore, consumer demand for inexpensive and easy-to-install XLPE pipes for heating has increased.

These materials are excellent for arranging indoor underfloor heating. They are comfortable and produced in bays.

Using polyethylene pipes for heating, the technical characteristics of which make it possible to minimize the number of connection points, a very tight pipeline can be installed.

These products have a large number of positive characteristics:
High fatigue strength. It remains even at an operating temperature of 95C;
Ability to maintain a stable shape;
Crack resistant polyethylene pipe;
Excellent impact tolerance and durability in incised areas. These characteristics are maintained even at very low temperatures of -50 degrees.
In polyethylene pipes, strength is excellently combined with flexibility;
Excellent wear resistance to abrasion;
Good shrinkage characteristics;
Resistance to the influence of chemicals;
Corrosion resistance;
Does not contain halogens and heavy metals.

Flaws
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Polyethylene pipes for heating, the technical characteristics of which have whole line positive points, nevertheless, they are not devoid of some disadvantages:
XLPE pipe is UV sensitive. In the world, its material quickly collapses, and the pipe cracks and breaks;
It is not recommended to use brass fittings for PE pipes hidden under a screed or plaster;
The operating capability of these products must not be exceeded.

What you need to pay attention to when choosing
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When buying XLPE pipes, you should pay attention to:
Stitching method. Such indicators are marked with the letter E when the molecules are crosslinked with reagents or irradiation. The letter P indicates the presence of peroxides, organosilants are denoted by the letter S, and nitrogen - N. The highest degree of crosslinking is for products marked PEX – P. Most often they are used for heating mains.
Presence of protection against ingress of oxygen. It is an aluminum layer or an ethylene vinyl alcohol coating.
Pay attention to UV protection. This is labeled - UV (this is partial protection). UV-1 indicates complete protection, and the addition of additional stabilizers is indicated by the letters UV-2. For a heating network, it is better to opt for products with the highest degree of protection, the higher it is, then the lower the possibility of bacterial growth in water.
Diameter. The diameter of the manufactured products can be from 10 to 280mm, and the wall thickness from 1.7 to 29.9mm. For the heating system, it is recommended to use products with a diameter of 16 to 20 mm.

Applications
Polyethylene of which are ideal for pipelines for various purposes, have proven to be versatile and reliable. Therefore, they are used for:
Arrangement of the "warm floor" system in residential and industrial buildings;
Carrying out the mains of cold and hot water supply.

Such pipelines operate reliably and without accidents for a long time.
The main advantages of such water pipes:
Long-term stock of service - almost 50 years. Because all parts are manufactured to the highest standards.
Reliability of connections, due to the fact that the fittings do not require auxiliary seals.
Versatility. The pipes are resistant to high pressure. They perfectly tolerate temperature extremes. This allows them to be used in private and industrial construction.
Low pressure loss. The narrowed diameter of this type of pipe is compensated by expansion at the cut end of the billet.
Compatibility. If necessary, polyethylene or brass fittings can be used to connect a homogeneous and multi-layer product.
Absolute harmlessness. All items are made from natural materials.
New manufacturing technologies. All production methods for these materials are safe and aimed at increasing the strength of the products. The stitching is performed by the action of an electron stream. Therefore, they are better than others for the heating network, for the installation of "warm floors" and for water supply.
The ability to hide the layout. The entire line can be masked with plaster in the wall or in the floor.

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The workpieces are calibrated;
A connecting ring is put on the workpiece;
With the help of a press, a connection is made.

The resulting connection comes out tight and reliable, leaks in it are excluded.

Why XLPE is better than polypropylene and metal-reinforced plastic
And I must say right away that polyethylene pipes, the technical characteristics of which are so multifaceted, are the most the best solution, because:
With the help of these pipes, long-lasting communications are created that have been used for more than 50 years;
Making connections with such products is convenient and takes little time. Laying is done using fittings without auxiliary seals;
These pipes are very convenient to store, as they do not take up much space;
They are made in bays that are not difficult to transport;
Absolute environmental friendliness.

Cross-linked polyethylene pipes for heating have a high reliability and a long period of use. These products meet all quality standards and are perfect for arranging a heating, water and gas supply network.

Today, an established heating system is, first of all, a guarantee that the house or apartment will always be cozy and comfortable for all household members, even in the most severe frosts. And fortunately, the use of modern materials and technologies allows you to achieve the longest and most productive operation of any heating system. At the same time, responsibility for the direct connection between all elements and communications lies on the pipes, on the choice of which the serviceability and service life of the heating equipment depends.

Recently, the use of polyethylene pipes has become a very popular solution for arranging water supply and heating systems. They are have a lot of advantages in comparison with other analogues on the market, but at the same time certain technical features certainly worth considering before proceeding with their direct operation. That is why this article will be devoted to these important issues.

Features of polyethylene pipes

First of all, it should be noted that pipes made of ordinary polyethylene, which are designated by the PE symbols, are intended for water supply and sewerage systems, including drinking water. This is due to the following features of pipes made of similar material:

Due to the incompatibility of this type of pipes with high temperatures, scientific and technological progress did not stand still and contributed to the design of special pipes made of cross-linked polyethylene, which are usually denoted by the abbreviation PEX. They are intended for various heating and water supply systems. hot water, the coolant temperature of which does not exceed 90 degrees.

XLPE pipes for heating

In order to obtain a more durable polyethylene, this material was subjected to a special treatment under high pressure conditions, as a result of which the molecules formed even stronger bonds among themselves in the form of transverse lines. The so-called Stitching can be done in several ways, namely:

by irradiation with electrons of polyethylene in the environment electromagnetic fields;
using polyethylene processing peroxides;
through the use silane gas;
by processing polyethylene nitrogen compounds.

The aforementioned technological processes contributed to a significant increase in the strength and thermal stability of PEX pipes, which allows them to be used as an element individual and central heating, hot and cold water supply, radiator and panel heating systems, as well as for systems "warm floor" and "snow melting". Pipes made with peroxides are considered to be of the highest quality.

XLPE pipes are used subject to certain parameters, namely:

maximum continuous operating temperature should not exceed 90 degrees, but in force majeure circumstances, the pipes are able to withstand a temperature of 100 degrees for some time;
maximum permissible operating pressure in the system should not exceed 10 bar at a temperature of 90 degrees and 25 bar at a temperature of 0 to 25 degrees.

A feature and at the same time a lack of material from which this type of pipe is made is high oxygen permeability, which leads to the impossibility of using them in closed heating systems in their pure form. That is why they are covered with a special protective layer of polyvinylethylene or reinforced with a layer of aluminum foil.

The connection of XLPE pipes is carried out using fittings, which can be made from various materials, namely polymer, brass and bronze. The highest quality and tested are polymer fittings, which have shown themselves at their best for many years. The algorithm for connecting such pipes can be described as follows:

the end of the connecting pipe is extended flaring tool, in order to give it a larger diameter;
then in this hole is placed fitting fitting;
in order to increase strength, the tension sleeve is attached to the pipe using press.

This technology makes it possible to significantly increase the service life and reliability of such connections, which in terms of quality fully correspond to the long service life of the XLPE pipes themselves.

For private houses, people prefer to use polypropylene pipes:

Advantages and disadvantages of polyethylene pipes

They have many advantages that distinguish them from other types of pipes intended for heating systems, but at the same time, some significant disadvantages, the study of which is mandatory when choosing them. So, to the primary positive aspects of exploitation PEX pipes can be attributed:

Despite the many positive characteristics, the disadvantages of PEX pipes in heating systems also occur. It should be noted that in the case of using brass fittings, direct contact with various materials for plaster and screed must be limited, since this will lead to corrosion and correspondingly poor functioning of the system... The disadvantage is also the vulnerability to ultraviolet rays, which leads to the need to use them in closed communications.

When choosing pipes made of cross-linked polyethylene, it is necessary, first of all, to compare the technical parameters of this heating element with the characteristics of the living space where they will potentially function. If characteristics such as pressure and temperature of the existing heating system exceed the threshold values of PEX pipes, it is better to refuse to use them. But, as practice shows, such cases are extremely rare. Therefore, based on the foregoing, it is safe to say that PEX polyethylene pipes fully comply with modern conditions, which are put forward by heating systems operating in the vastness of our country.

In order to determine the choice of pipes for heating and not be mistaken, it is recommended to read this article:

How polyethylene PEX pipes are made

Flexibility, strength, durability, the ability to regain shape after damage are the main, but far from the only, advantages of XLPE pipes. They are confidently pushing them out of the market, they are actively used in the installation of warm floors, plumbing (hot and cold) and heating systems. Are they really that versatile? Let's put all the dots on "i" and try to figure out which pipes made of cross-linked polyethylene for underfloor heating, heating and water supply are better to choose, what to look for when buying and which manufacturers you can trust.

# 1. Features of production

If ordinary polyethylene (a polymer consisting of carbon and hydrogen atoms) is acted upon in a special way, then some hydrogen atoms are separated, leading to the formation of a new bond between carbon molecules. The process of obtaining these additional carbon bonds is called stitching... Polyethylene is affected by various substances and methods, so the degree of crosslinking may differ. The optimal indicator is 65-85%.

Crosslinking improves the properties of polyethylene: resistance to high temperatures increases, flexibility, wear resistance improves, and the possibility of self-healing after mechanical stress appears. The stitching process was developed in 1968 by the Swedish chemist T. Engel, but underestimated his invention, considering it uncompetitive. The patent was bought from him by the WIRSBO company, which was the first in the world to start industrial production pipes of cross-linked polyethylene (PEX) and is still the leader in this field. Such products did not hit the domestic market immediately, but now they are very popular.

PEX pipe usually consists of three layers: inside - cross-linked polyethylene, outside - oxygen protective layer, they are connected with glue. On sale there are also 5-layer pipes... They have another layer of glue and cross-linked polyethylene on top of the oxygen protective layer.

No. 2. PEX pipe stitching method

The most important parameter when choosing XLPE pipes is the stitching method used by the manufacturer. The number of additional connections formed, and, consequently, the performance of the product depends on it.

To form additional bonds (bridges) in polyethylene, the following stitching methods are used:

peroxide crosslinking, such pipes are marked with PEX-A;
silane crosslinking, PEX-B;
radiation crosslinking, PEX-C;
nitrogen crosslinking, PEX-D.

PipesPEX-A obtained by heating raw materials with the addition of peroxides. The density of stitching for this method is maximum and reaches 70-75%. This allows us to talk about such advantages, as excellent flexibility (maximum among analogs) and memory effect (when unwinding the coil, the pipe almost immediately takes its original straight shape). Kinks and kinks that may appear during installation can be corrected by slightly heating the pipe. Basic minus- this is a high price, since the peroxide crosslinking technology is considered the most expensive. In addition, during operation, chemical substances are washed out, and somewhat more intensively than in other PEX pipes.

PipesPEX-B produced in two stages. First, organic silanides are added to the raw materials, resulting in an under-cross-linked pipe. After that, the product is hydrated, and as a result the crosslink density reaches 65%. Such pipes are notable for their low price, they are resistant to oxidation, and have high pressure values at which the pipe ruptures. In terms of reliability, they are practically not inferior to PEX-A pipes: although the percentage of crosslinking is lower here, the strength of the bonds is higher than with peroxide crosslinking. From cons note the rigidity, so it will be problematic to bend them. In addition, there is no memory effect here, so the original shape of the pipe will be poorly restored. When kinks appear, only couplings will help.

PipesPEX-C obtained with the so-called. radiation crosslinking: polyethylene is exposed to electrons or gamma rays. The production process requires careful control, because the uniformity of the stitching depends on the position of the electrode relative to the pipe. The degree of crosslinking reaches 60%, such pipes have a good molecular memory, they are more flexible than PEX-B, but cracks can form on them during operation. Creases are corrected only with couplings. Such pipes are not widely used in Russia.

PipesPEX-D produced by treating polyethylene with nitrogen compounds. The degree of cross-linking is not high, about 60%, therefore, in terms of performance, such products are significantly inferior to their counterparts. The technology is actually a thing of the past and is almost never used today.

On sale you can find PEX-EVOH pipes... They differ not in the method of stitching, but in the presence of an external additional anti-diffusion layer of polyvinylethylene, which further protects the product from oxygen entering the pipe. By the way of stitching, they can be any.

The pipes are considered to be of the highest quality.PEX-A but their high cost has led many to use PEX-B pipes. These two types of products are most common in the market, and the choice between them depends on the budget, personal preferences and the characteristics of the pipeline that needs to be built with their help.

Do not confuse XLPE pipes with:

No. 3. Advantages and Disadvantages of PEX Pipes

It is difficult to call XLPE pipes a unique and revolutionary product, but Indeed, the material has many advantages:

Among the cons:

Cross-linked polyethylene pipes are, of course, more expensive than cast iron or conventional polyethylene pipes, but they are still quite affordable, however, you will also have to spend money on the appropriate fittings. Installation is carried out using a special hand tool... In this case, it is very, very important not to damage the protective layer. We can say that the durability of the pipeline will depend on care during work, which is why it makes sense to entrust the installation to certified craftsmen.

No. 4. Scope of use

The performance characteristics of XLPE pipes allow them to be used for building the following engineering networks:

PEX pipes are not used for industrial purposes - material large diameter(for example, for a main water supply system) is expensive.

No. 5. XLPE or reinforced plastic?

XLPE pipes and reinforced plastic pipes are the main competitors when it comes to arranging a water supply system, heating system or underfloor heating. They have a lot in common. Both types of pipes are flexible enough, strong, resistant to corrosion and relatively easy to install - you certainly won't have to weld anything. True, it is still easier to install than PEX pipes, with which you need to be extremely careful.

Have metal-plastic pipes the coefficient of thermal conductivity is slightly higher (0.45 versus 0.38), but they will not survive freezing inside the coolant. PEX pipes, however, after the water in the system has melted, it will be possible to operate as before. Moreover, some types of PEX pipes easily regain their shape. Resistance to high temperatures and pressure is high for both types of pipes: metal-plastic can withstand pressure up to 25 atm at a temperature of 25 0 С, can be operated at coolant temperatures up to +95 0 С with a short-term increase to +120 0 С, however, the maximum pressure is 10 atm. Thus, the performance characteristics are quite comparable with the similar parameters of XLPE pipes, which we presented above.

The choice depends mainly on the features of the operation of the water supply system and the budget. The range of prices among pipes, even within the same group, is significant, but PEX pipes are often cheaper than metal-plastic pipes.

No. 5. Diameter and length

Cross-linked polyethylene pipes are sold in coils of 50, 100 and 200 m.Pipes with a diameter of 40 mm or more are sold in lengths of up to 12 m.On the pipe along its entire length information about material of manufacture (type of stitching), operating temperature, pressure, diameter, date and place of manufacture. For added convenience, some manufacturers apply risks to the product exactly every meter.

The choice of pipe diameter depends on the type of pipeline, water pressure in it, the number of consumers and other parameters. General recommendations for the selection of the diameter are as follows:

pipes with a diameter of up to 15 mm (10.1 * 1.1, 14 * 1.5 and others) are suitable for supplying water from the main water pipe to taps;
pipes 16 * 2 are used to organize warm floors, 16 * 2.2 are suitable for hot water supply and radiator heating. Pipes with a diameter of 16-20 mm can be used as the main pipe for cold and hot water supply to apartments and small private houses;
pipes 20-32 mm are suitable for organizing water supply in cottages, they are also used for heating, pipes with a diameter of more than 20 mm are usually not used for warm floors;
pipes 40-50 mm are suitable for risers in apartment buildings;
pipes with a diameter of 50-63 mm are used in both heating and water supply systems.

Usually, the manufacturer indicates for what purposes this or that pipe is best suited, for example, for heating, hot water supply, or it is universal in use.

Calculate length it is not difficult, but for this there must be an accurate plan of the plumbing system, radiator or floor heating. We measure the length of the proposed pipeline and multiply the resulting value by 1.2 - this is a margin for unforeseen situations that may happen during installation.

No. 6. XLPE Pipe Fittings

Looking ahead, we note that it is better to take fittings from the same manufacturer as the pipes. Even with the same declared dimensions, the difference in the diameter of the products different manufacturers can reach 0.5 mm. In this case, it is difficult to talk about the absolute tightness and reliability of the system.

For connecting individual piecesPEX pipes use the following types of fittings:

It is not allowed to weld, solder and glue the seams of XLPE pipes.

No. 7. XLPE pipe manufacturers

To be 100% sure that the pipeline will not have to be repaired in a couple of years, or even changed at all, it is better to take pipes from a trusted manufacturer, which gives a guarantee for all products. Large companies will not risk their reputation and produce low-quality products. So, today on the market for pipes made of cross-linked polyethylene such main manufacturers:

Rehau, Germany. These pipes are considered the standard of quality, but they are also expensive. The manufacturer offers a wide range of pipes of different diameters, a huge selection of fittings. In this regard, the company's products are confidently ahead of competitors. All pipes are made of PEX-A cross-linked polyethylene, covered with an oxygen-protective layer of ethylene vinyl alcohol (EVAL) on top. The company produces pipes of several series, you can distinguish them by color. The assortment includes products suitable for organizing cold and hot water supply, heating. The manufacturer speaks of special strength and reliability, states that the service life of pipes is about 50 years, and they can be laid without fear and;
Uponor, Germany. Pipes are made of cross-linked polyethylene of the PEX-A type, the products are characterized by increased flexibility and durability (about 50 years). Suitable for the installation of any type of pipelines, incl. for hidden laying;
BIR PEX, Russia. Produces PEX-B pipes. Products differ affordable price and high quality, the company takes into account the peculiarities of domestic conditions, so the pipes are ideal for arranging heating and water supply systems. The manufacturer uses high quality English equipment;
Valtec, Italy. The company manufactures PEX-B cross-linked polyethylene pipes. According to the company, this type of crosslinking is optimal because it provides a reliable, uniform connection of individual polymer chains, and at the same time the cost of the product remains affordable for most consumers. Pipes are suitable for arranging underfloor heating, hot and cold water supply,;
Frankische, Germany. Produces PEX-A pipes with excellent performance, but the company's products have not found much distribution in the domestic market;
SANEXT, Russia. Big company produces everything necessary for the heating system. The range also includes PEX-A pipes with an EVOH protective anti-diffusion barrier. The products are universal, suitable for heating and water supply, diameter from 16 to 63 mm;
Rooster, Russia. It produces universal pipes of the PEX-B type, as well as fittings and a huge range of equipment for heating and water supply systems;
KAN-therm, Germany. Produces PEX-C and Pert pipes, all products receive a protective coating to resist the passage of oxygen;
Watts, Germany. The company produces PEX-B pipes of various diameters. The products can be used in various systems;
Tiemme, Italy. The manufacturer manufactures pipes of the PEX-B type of different diameters, claims durability at the level of 50 years.

Most manufacturers indicate exorbitant warranty periods, it is 20-30 years, and somewhere even all 50. The terms of this warranty must be studied carefully so that they do not violate them during installation and operation, otherwise the manufacturer will have the right not to fulfill its obligations.

Is a polyethylene pipe suitable for heating? We will get acquainted with a relatively little-known material - cross-linked polyethylene, we will analyze its features and the methods of installation used.

But first, some general information.

Yes, polyethylene. Yes, heating. No, it will not explode.

About polyethylene

What do we know about this material? Well, it's transparent ... and it seems to be made into bags. This is where the list of well-known information seems to end.

Let's try to expand it.

Polyethylene for over a century... It was first discovered by accident by the engineer Hans von Pechmann in 1899 and was immediately forgotten.

In 1933, the material received a second life in the form of insulation for a telephone cable.

The material is dielectric, elastic (and retains elasticity at temperatures below zero) and very chemically resistant. Concentrated sulfuric acid can be stored in a polyethylene can for an unlimited time.

Polyethylene does not absorb water and does not let it through, representing a reliable waterproofing.

Tensile strength is large enough so that pressure pipes of cold water supply are made of polyethylene.

Benefit: The physical properties of polyethylene, including density and strength, differ depending on the polymerization conditions.

Moreover, the lower the pressure during the reaction, the stronger the resulting material. Distinguish between low, medium and polyethylene high density.

All types of polyethylene soften at 80-120C... Taking into account the fact that the pipe will be under pressure in the water supply system, manufacturers limit the operating mode of polyethylene pipes to a maximum temperature of ... 40 degrees.

Hence - an unambiguous and final verdict: polyethylene pipes are not suitable for heating. Dot.

Plain polyethylene pipes are not suitable for hot water.

Useful modification

In its normal state, polyethylene consists of long monomolecular chains. However, there are a number of operations that can change its structure.

Due to heating in the presence of a catalyst, bombardment with electron beams, or simple immersion in water with a catalyst and special additives, molecules begin to form not only longitudinal but also transverse connections. Staple. The result is a fundamentally different material, which is commonly called cross-linked polyethylene (PE-C, or PE-X).

To understand how its properties have changed, we will give a description of a cross-linked polyethylene pipe for heating, manufactured in Germany under the Gabo Systemtechnik brand.

The pipe is capable of working for the declared 50 years in the 90C / 7 bar or 70C / 11 bar mode.
The maximum operating temperature for it is 95C - the same as manufacturers usually indicate for reinforced polypropylene.
The pipe remains extremely flexible. The minimum bending radius is only 6 of its diameters. From a practical point of view, this means that when you install your own XLPE heating, you can get by with a minimum number of relatively expensive fittings.

Thus, cross-linked polyethylene is suitable for heating systems without any reservations: according to the current SNiP, the temperature (see. temperature graph heating systems) in the internal engineering networks of residential buildings should not exceed the same 95C that the pipe, as we just found out, will perfectly withstand.

Don't be fooled: XLPE can be melted too. But at a fairly high temperature.

Production

Technology

As an example of production technology, let's take information from the website of the dealer of those same Gabo pipes.

The Germans are traditionally famous for their pedantry and in terms of compliance with technological standards, they are certainly ahead of the rest.

High-density polyethylene in the form of granules is melted and pushed through the annular hole of an extruder - a special press that forms a pipe of the required section.

During the extrusion process, the material homogeneity is continuously monitored.

A pipe intended for heating systems (for example, two-storey house) and underfloor heating, gets an oxygen barrier - the pipe is covered with a film of quick-drying ethylene vinyl alcohol.

Useful: all pipes for transporting drinking water are mixed with additives that make it opaque, including for ultraviolet radiation, even during the extrusion process.

Finally, the finished pipe is crosslinked. The most technologically advanced and cheapest production methods are with the use of reagents; electron beam irradiation is slower and more expensive.

The method used is not directly named: the seller's website vaguely states that "irradiation with fast electrons is the most environmentally friendly." From this we draw the cynical conclusion that, most likely, the Germans, like many other manufacturers, use a reaction with a silane and a catalyst.

The finished pipe is delivered to dealers in 200-meter coils. The retail price for a meter of a 16 mm pipe is about 50 rubles.

The extruder in the photo turns the hot amorphous mass into a strong pipe.

Regulations

Pipes made of cross-linked polyethylene fully comply with GOST 52134-2003 "Pressure pipes made of thermoplastics and their connecting parts".

What interesting things can we find in the text of this document?

In addition to the material (PE-X), the marking must indicate the stitching method. Certainly, it is not difficult to bring the Germans to clean water - it is enough to study the pipe.
In addition, the marking of all thermoplastic pipes includes an indication of the outside diameter, wall thickness and maximum working pressure.

The standard provides a table of pipe sizes. In the XLPE column, we find a range of dimensions from 10 millimeters outside diameter with a wall thickness of 1.3 mm to 250 millimeters with walls as much as 3.4 centimeters thick.

Deviations from the specified dimensions in the average outer diameter are permissible only upwards and depend on the nominal size: for a diameter of 10 mm, a deviation of 0.3 mm is permissible, for 250 - of 2.3 mm.

The wall thickness can also only be exceeded. Downward deviations are unacceptable. The range of deviation values from 0.4 mm for the thinnest pipes to 3.7 for the thickest.

There are no physical properties of the material in the standard, however, this information will be useful.

Application features

We have already found out that XLPE is suitable for heating. Where and how best to apply it?

The ideal option is to lay the pipe as a warm floor. The combination of good thermal conductivity and low coefficient of thermal expansion makes polyethylene pipes more than suitable. The opportunity to purchase a continuous pipe up to 200 meters long will also come in handy.

The instruction, in general, differs little from laying any other water-heated floor:

The pipe is laid out on the rough floor with a spiral or snake and recessed into the screed.
All connections are above the floor. The reason is clear: one-piece pipes rarely leak. 9 out of 10 leaks are at connections, and it would be better for them to be accessible.
The first heating start-up (see heating system with forced circulation) takes place only a month after the screed has been laid, when the concrete has gained strength. Warming it up earlier, you will not speed up drying, but cause it to crack.

It is clear that for a warm floor, the maximum operating temperature of cross-linked polyethylene is clearly excessive. Temperatures above 40C will already feel uncomfortably high. Typically, the temperature of the coolant in the pipes of the underfloor heating does not exceed 30 degrees.

One-piece pipe is laid in the screed, without connections.

How are XLPE heating pipes connected to brass and plastic fittings?

You will need special equipment. At least an extender, and scissors for cutting are also useful.

The principle of connection uses the molecular memory of the material: the pipe can change its linear dimensions for some time, but will quickly return to its original dimensions.

The pipe is cut to size.
A retaining ring is put on it. It should protrude a millimeter beyond the edge of the pipe.
The head of the extender is inserted into the pipe and in several movements with a twist between them stretches the pipe, plunging further and further until the head is completely inside it.
Then the extender is quickly removed, and the stretched pipe is put on the fitting, where it returns to the original diameter and securely encloses it.

Tip: Applying graphite grease will reduce tensile force and extend tool life.

Sometimes brass rings are also used, which are put on after connecting to the fitting.

Polyethylene pipes for heating: do-it-yourself video instructions for installation, features of cross-linked polyethylene, photo

121) Polyethylene pipes for heating: DIY video instructions for installation, features of cross-linked polyethylene, photo

The use of cross-linked polyethylene for heating systems

The heating system requires the use of high-quality and wear-resistant materials that are not afraid of high pressure and frequent temperature changes. All the above stated characteristics correspond to polyethylene pipes for heating.

Cross-linked polyethylene for underfloor heating

In order to impart flexibility, chemical and mechanical resistance to polyethylene, it is electronically stitched. There are several different methods for the production of cross-linked polyethylene and, depending on the technology, the technical characteristics of the material change, however, the main advantages and disadvantages are still common.

Advantages of XLPE

Unlike ordinary polyethylene, sewn polyethylene does not soften or deform when exposed to high temperatures. It is this property that allows the material to be used for heating and underfloor heating systems. In addition, cross-linked polyethylene (PEX) has the following advantages:

Complete absence of corrosion;
Pipes do not overgrow or silt;
Low weight;
Ease of installation and transportation;
Stably tolerates large drops in pressure and temperature;
Does not crack;
Excellent sound insulation;
Resistance to negative temperatures;
Possesses molecular memory;
It is environmentally friendly for humans and any other living organisms;
Inexpensive cost;
Strength;
Long service life (according to manufacturers, it is about 50 years).

Cross-linked polyethylene for heating

The main disadvantages of the material

The positive qualities of cross-linked polyethylene made it indispensable for heating systems and underfloor heating. Nevertheless, there are still some disadvantages, among which it is worth highlighting:

Lack of resistance to UV rays;

To reduce the destructive effect of ultraviolet radiation on cross-linked polyethylene, pipes are covered with a special protective varnish.

Possibility of mechanical damage, for example, by rodents;
No resistance to the influence of surfactants;
Destruction by oxygen.

When oxygen enters the inner layers of the pipeline, it is quickly destroyed. It is for this reason that many manufacturers add a protective layer against the effects of oxygen, the so-called oxygen barrier. This reduces the risk of damage to the product, but increases its cost.

PEX pipe design and production method

A cross-linked polyethylene pipe is a multilayer structure that consists of five balls. The main layers are as follows:

XLPE inner ball;
Glue ball;
Oxygen barrier;
Glue ball;
XLPE outer ball.

PEX pipe construction

It is this five-layer structure that ensures the high temperature resistance of the material, because it does not deform even with the indicators of the transferred liquid up to 95 ° C. That is why PEX is an excellent choice for heating and underfloor heating.

For the manufacture of the pipeline, the extrusion method is used, which consists in extrusion of the required shape from molten polyethylene. All pipes are then vacuum calibrated. Products are supplied for sale in coils or cuts, depending on the diameter.

Product Specifications

The unique properties of XLPE have pushed it to a level with many solids. Key material characteristics include:

Melting point - 200 degrees;
Combustion temperature - about 400 degrees;
Elongation at break - 350 - 800%;
Density - 940 kg per cubic meter

Molecular crosslinked polyethylene tubing is manufactured in a wide range of diameters. Manufacturers offer sizes from 12 to 250 mm, but diameters of 16 - 25 mm are most popular with consumers.

PEX stitching methods

There are about 15 methods of cross-linking polyethylene, but three of them are most widely used.

Today, stitching methods are in demand:

More expensive, however, and a better quality crosslinking method is peroxide. It is thanks to him that it is possible to bind about 85% of free molecules. This allows the material produced in this way to have increased resistance to mechanical stress and have a higher melting point.

PEX-a - best method production of cross-linked polyethylene, all other options are just an attempt to reduce the cost of the material.

Reinforced piping for heating

One of the latest innovations on the market of materials for heating and underfloor heating is reinforced pipe made of cross-linked polyethylene. It is even more robust and heat resistant than conventional PEX. The main difference in the production technology is the introduction of nylon threads into the pipe walls, which occurs at the stage of extrusion of the mold from hot melted polyethylene.

PEX-c XLPE pipes

Reinforcement methods can be as follows:

The reinforced pipeline can withstand even such loads as pressure of 30 atmospheres, does not crack when twisted or bent. But the cost of the products is also higher, because the production requires expensive equipment.

Key XLPE manufacturers

Cross-linked polyethylene is the most successful material for installing heating systems and underfloor heating. Today, a whole group of foreign and domestic companies is engaged in the production of high-quality and durable products. Key manufacturers are:

Rehau is the world leader in the production of XLPE pipes for heating and underfloor heating.

Rehau XLPE

The leading position in the world market today is taken by the company Rehau. It is her products that have excellently proven themselves due to their excellent quality and good performance. The price of the products is not the cheapest, so many developers are looking for more budget options, for example, products of the STOUT brand.

STOUT is a professional plumbing equipment for the installation of heating and water supply systems. The products are manufactured at the same European factories where other brands of the "premium" segment order their goods.

The main items of the STOUT product range are covered by a 5-year warranty. All parts of the system are ideally suited to each other, are easy to install and maintain, and are adapted for operating conditions in Russia.

XLPE pipes

Different manufacturers use different methods of crosslinking polyethylene: PEX-a, PEX-b, PEX-c. In the best way crosslinking is currently recognized as peroxide (PEX-a), it is for this reason that it is recommended to stop your choice on products trade marks Rehau, Uponor and STOUT, which are produced using this technology.

Features of material installation

Installation of heating and underfloor heating using cross-linked polyethylene can be carried out in two main methods:

Using compression fittings;
With the use of press fittings.

More simple option installation, which also allows you to repeatedly disassemble the structure at the docking point, if necessary, is installation using compression fittings. To install a warm floor using this technology, you must perform the following steps:

Slide the compression nut onto the pipeline.
Put on the split ring.
Push the pipe onto the union.
Tighten with a wrench.

Installation of cross-linked polyethylene

Attention! Be careful when tightening the crimp nut as excessive force can damage the pipe.

Installation of underfloor heating using press fittings creates a permanent connection. It is necessary to prepare the press for installation in advance and follow the instructions below:

Fit the clamping sleeve.
Insert an appropriately sized expander into the pipe.
Insert the pipe into the nipple of the fitting.
Press the sleeve onto the fitting.
Wait a few seconds and get solid and reliable connection... Due to the molecular memory of the material, the pipe cannot be removed from the fitting.

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Why is cross-linked polyethylene better than other pipes for heating?

What quality characteristics of cross-linked polyethylene to pay attention to when choosing pipes for heating, what these pipes consist of and what is the method of stitching them, as well as how to mount them correctly

Cross-linked polyethylene pipes for heating: advantages and disadvantages, installation features

Low temperature heating systems are becoming more common. Modern appliances and systems allow you to heat your home at water temperatures up to 80 ° C. This has driven consumer demand for inexpensive XLPE pipes for heating. They are easy to install and perfect for underfloor heating.

Products are sold in coils, which is very convenient. It should also be noted that it is possible to minimize the number of connection nodes, which makes it possible to obtain a sealed pipeline. The described pipes have a low mass, and they can be used to create water supply and heating systems of increased complexity.

Usage construction hair dryer allows you to save the consumption of materials that would be required on the folds during the installation of steel products. If the pipe is heated to a high temperature, it will be able to take any shape, and when cooled down, it will retain it. The advantage of these products is that they can be installed without professional assistance, which saves money. And you can choose the connection method that is within your power.

Main advantages

XLPE pipes for heating have many advantages, among them should be highlighted:

maintaining a stable shape;
excellent shock tolerance;
high fatigue strength;
crack resistance;
combination of flexibility with high strength;
excellent shrinkage characteristics;
high wear resistance to abrasion;
corrosion resistance;
resistance to chemicals;
absence of heavy metals and halogens in the composition.

XLPE heating pipes are capable of maintaining fatigue strength even when exposed to temperatures up to 95 ° C. Products withstand shock well, and their characteristics are preserved even when exposed to low temperatures down to -50 ° C.

Main disadvantages

XLPE pipes for heating have some drawbacks. For example, products are sensitive to ultraviolet light. If, after installation, the pipes are left unprotected, then the material at their base will quickly collapse, and the pipe itself can break off and become covered with cracks. It is not recommended to use brass fittings for such pipes that are covered under plaster or screed. When purchasing such products, you should remember that it is not recommended to exceed the possibilities of their operation, as this can negatively affect the durability and strength.

Installation features: choice of materials and tools

PEX pipes made of cross-linked polyethylene for heating are products with a marking, the end of which provides for the presence of one of four letters: a, b, c or d. The most common recommended are the first two types - PE-Xa and PE-Xb. In this case, we are talking about stitching methods.

Regardless of which technology is used in the production process, the result is a strong complex three-dimensional polymer chain of ethylene molecules. You can use such products for a drainage device, water supply and as a basis for an underfloor heating system. A high heat transfer coefficient is good for heating systems. Whereas if such pipes are planned to be used for water supply, then additional thermal insulation is required, otherwise the water will cool down on the way to the point of consumption.

Installation does not require highly specialized skills and special tools, but there are some nuances that should be taken into account. When choosing XLPE pipe fittings, you may prefer the crimp variety, which is a compression product. Such a connection will be able to withstand pressures up to 2.5 MPa.

For installation, a welding machine can also be used, with the help of it you can achieve a reliable connection that can withstand up to 12 MPa. In any case, the main tool will be used - a pruner knife. In the first method, you should take care of the availability wrench, in the second case, you will need a hydraulic or manual press, and for welding, you should prepare a welder for pipes made of cross-linked polyethylene. Products have high elasticity, therefore, during the installation process, they should be held in place, providing fixation with special clips-latches.

Pipes of the "Rehau" brand and reviews about them

These pipes are manufactured by the world-famous German concern, which sells products with a high threshold of resistance to damage. Experts keep a high standard of quality, and pipes remain in demand and popular. According to consumers, the Rautitan series is specially designed for heating and water supply systems, because it can withstand high temperatures.

The manufacturing process uses crosslinking at the molecular level. This eliminates leakage, in addition, the pipes gain memory when bent. The outer layer of such products is made of aluminum, which provides additional strength. As buyers emphasize, even if the outer layer is damaged during operation, the inner polymer coating will prevent leakage.

The manufacturer sells pipes with the connection technique using a slip-on sleeve. The connection is one-piece, which guarantees long-term tightness. Rubber O-rings are not used.

When installing Rehau pipes, there is the possibility of optical control. The sliding sleeve is installed according to a specific method. At the first stage, it is necessary to carry out the extension, and then insert shaped part and slide the sleeve. According to consumers, such an installation can be done independently. Salt and scale are not formed on the surface of the products.

The pipes provide low permeability of sound and noise absorption, which is especially true when compared with metal pipes. The systems are environmentally friendly and safe. Cold pressing can be used for a simple and quick connection. If pipes with a diameter of 32 mm are used, then their bending is carried out without the use of a tool, which, according to DIYers, is very convenient for private installation.

Rehau pipes are supplied with a 30-year, tested warranty. The installation of such pipes, although it is more expensive compared to the installation of metal-plastic products or polypropylene pipes, but you can be sure that such systems will last much longer.

During installation, the human factor is reduced to a minimum. Installation of such products is possible even with low temperatures when outside the window is -15 ° C. If you are interested in the diameters of XLPE pipes for heating, then they are supplied with parameters ranging from 16 to 63 mm.

Pipe cost

Before purchasing, you should be interested in the price of a cross-linked polyethylene pipe. For Stout PEX-a, the cost is 59 rubles. per meter. In this case, we are talking about a 16 x 2 mm product. In the bay 500 m. By purchasing a Rehau Rautherm S pipe with dimensions of 14 x 1.5 mm, you will pay 61.96 rubles. per meter. In the bay 120 m.

If the parameters of the product are increased to 17 x 2 mm, then you will have to pay 63.33 rubles. per meter. When purchasing a Kalde PEX-b product with an oxygen layer and dimensions 16 x 2 mm, you will pay 65.27 rubles. per meter. In the bay 160m.

Installation of pipes for the underfloor heating system

Cross-linked polyethylene pipes for underfloor heating are laid:

Laying with a snake is considered simpler, but the heating will not be so uniform. The distance between the products should be within 35 cm. One circuit should have an average length of 40 to 60 m, but not more than 120 m. Otherwise, there will be increased heat losses, and the return coolant will have a low temperature.

Additional layers

When laying a cross-linked polyethylene pipe for underfloor heating, an insulating layer is located at the bottom. The following materials can act as it:

Styrofoam;
expanded polystyrene sheets;
reflector based on polyethylene foam.

Fastening is carried out with clips, staples or single hammer-in dowels. Some polystyrene boards are manufactured with an applied profile for fastening pipes. Such canvases are marked.

When pouring cross-linked polyethylene heating pipes, reviews of which were presented above, it is necessary to provide expansion joints in the screed to level the linear expansion. The floor can be started after the screed has hardened. The temperature of the coolant before entering the operating mode should increase by 5 ° C per day. If the pipe has anti-diffusion protection, then installation is carried out only after checking the top layer for damage.

Conclusion

When installing XLPE pipes for underfloor heating, you can use compression and pressure fittings. It is easier to carry out the work if you use the first option of the fitting, while you need a regular nut. The threads should be directed towards the location of the connector.

Press-on fittings can be used to form permanent connections. Docking is carried out using special equipment... At the first stage, a clamping sleeve is put on, and then an expander, which has the appropriate size, is inserted into the pipe.

Cross-linked polyethylene pipes for heating: advantages and disadvantages, installation features

The flawless operation of the heating system is the key to a comfortable and cozy stay of households indoors in any weather. Modern materials and the technologies used in the installation of heating systems make their work long and efficient. The main element of any heating system are pipes that connect all elements and communications. The choice of pipes should be approached very responsibly, since the service life of all equipment and its serviceability depend on this.

Recently, the arrangement of the heating and water supply system is carried out using polyethylene pipes. This material has properties that give it a great advantage over other analogues. However, during the operation and installation of cross-linked polyethylene heating, some technical features of this material should be taken into account, which should be learned in more detail.

Features of polyethylene pipes

Conventional polyethylene pipes, with the designation PE, are used for the installation of heating, sewer and plumbing systems including drinking water supply. Pipes made of such material have some features, among which the following can be distinguished:

Resistance to subzero temperatures... Operation and maintenance of polyethylene systems is allowed at -20 degrees. This is important when carrying out any production work in winter period, including the installation of new equipment and the repair of damaged areas.
Flexibility and ductility. These properties make it possible to avoid deformation of pipes, not only during bending. Flexible pipes for heating made of cross-linked polyethylene, they can expand when the working medium freezes and shrink when it thaws. In this case, the product takes on its previous shape.
The use of polyethylene pipes at a temperature of the working environment no more than 40 0 C.

The latter feature can be called a disadvantage, but progress in the scientific and technical direction helps to solve the problem. Thanks to this, special pipes made of cross-linked polyethylene were designed, which can be used in water supply and heating systems with a coolant temperature of up to 90 0 C. The new material has the designation PEX.

Characteristics of XLPE pipes

To obtain a material with higher strength characteristics, polyethylene was subjected to processing under high pressure... As a result, the polyethylene molecules formed stronger crosslinks.

To obtain a kind of "stitching", the following methods were used:

Polyethylene was placed in an electromagnetic field and irradiated with electrons.
The material was treated with peroxide.
The polyethylene was treated with nitrogen compounds.

The result of each method was durable and thermally stable polyethylene, which is quite suitable for use in individual and central heating systems, radiator and panel type, in hot and cold water supply systems, as well as for the "warm floor" and "snow melting" systems. Polyethylene pipes obtained as a result of treatment with peroxides are of higher quality.

For the operation of XLPE pipes, certain requirements must be met:

The maximum value of the operating temperature is no more than 90 0 C. However, in extreme cases, products made of cross-linked polyethylene can function for a certain time at temperatures up to 100 degrees.
The operating pressure in the system cannot exceed 10 bar, provided that the heat carrier is heated to 90 degrees, or 25 bar when the working medium is heated to no more than 25 degrees.

One of the features of cross-linked polyethylene is high oxygen permeability. This property is a disadvantage of the material, since it limits its use in its pure form, especially in closed-type heating systems. To eliminate this drawback, cross-linked polyethylene is reinforced with a layer of aluminum foil or protected with a special polyvinylethylene coating.

Connection of polyethylene heating pipes

XLPE pipes are connected using fittings made from a variety of materials, including polymers, brass and bronze. Polymer fittings are characterized by high quality and have shown themselves only from the best side for a long time. That is why the products are very popular with the consumer.

The process for fitting XLPE pipes is as follows:

Using a flaring tool, the end of the connecting pipe is attached larger diameter pushing it apart.
A fitting nipple is placed in the resulting hole.
Using a press, the tension sleeve is fixed to the pipe. This makes the connection more durable.

The use of such a technological process increases the service life of the joint and increases its strength. At the same time, the operational period of the connection fully coincides with the life of the cross-linked polyethylene pipes. If necessary, the heating pipes can be insulated with an appropriate material.

Advantages of polyethylene pipes for heating

XLPE pipes have a large number of advantageous points due to which they stand out from the general group of pipes used for the installation of heating systems. Of particular significant benefits the following can be distinguished:

High temperature resistance and excellent strength characteristics... Unlike polypropylene and conventional polyethylene pipes for heating, the new material will not change its shape when exposed to high temperatures.
Resistance to the formation of foci of corrosion... Compared to copper products, XLPE pipes do not corrode. Moreover, this process does not occur either inside the structure of the material or on the surface.
No build-up inside the pipes... The inner walls of PEX pipes are not covered with layers after transporting any aggressive medium. This is how they differ from most steel pipes, which after a certain period of time become less productive due to a decrease in the flow rate.

Restoration of the previous form... Many pipes lose their shape as a result of certain mechanical influences. However, XLPE pipes can expand or contract to certain parameters when exposed to low temperature or mechanical stress.
Low weight. A light weight material makes it more convenient to transport XLPE pipes and facilitates the installation process.
Easy installation and great possibilities... PEX pipes can be laid in any pattern, including kinking or a large number of bends. Connecting with fittings simplifies the installation process, as it eliminates the need for welding equipment, soldering and gluing.
Environmental Safety... Cross-linked polyethylene belongs to the group of environmentally friendly materials, therefore, PEX pipes can be used to transport clean drinking water.

However, such pipes cannot be called completely flawless due to the presence of some shortcomings.

Flaws

Firstly, when connecting XLPE pipes for heating using brass fittings, the list of materials used for screed or plaster is limited. It is better to exclude those that can cause corrosion of the fitting, so as not to degrade the quality of the system.

Secondly, XLPE pipes are characterized by low resistance to UV radiation, so it is better to use them in closed systems and communications.

Thirdly, it is recommended to use PEX pipes in systems that have pressure and temperature values that correspond to the threshold values of the pipes. When choosing pipes made of cross-linked polyethylene, you should carefully study the technical characteristics common system and the features of the living quarters where it is planned to install a heating system from the specified material.

Practical use of cross-linked polyethylene for heating shows that the material fully complies with the parameters and conditions. modern systems that function flawlessly on Russian territory.

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