PE-RT TEBO

The PE-RT TEBO system is designed for installation of heating systems, Underfloor heating, hot and cold water supply in multi-storey and
cottage construction Pipes and fittings are made of heat-resistant polyethylene, type 2 The connection of pipelines and fittings is performed by welding, using a pp-r pipe welding machine The range includes pipes and fittings with a diameter of 16 to 32 mm
Advantages of the PE-RT TEBO system:
- service life, 50 years
- wide range of applications (heating, water supply, Underfloor heating)
- reliability, tight monolithic connection in the places of welding of pipes and
fittings'
- frost resistance (the system can withstand several cycles of freezing/thawing)
- the possibility of embedment in the wall

PE-RT-a new type of heat-resistant polyethylene

Over the past years, heat-resistant polyethylene has become much more commonly used in the production of pipes used in industrial and household systems In this article, we will study in detail the characteristics of pipes made of PE-RT, as well as the methods of their connection during installation

Introduction

In 2010 Dow Chemical Company held a presentation dedicated to the latest developments in the field of creating materials intended for water and heating systems These new developments have contributed to the expansion of the use of PE-RT type II in the manufacture of pipes used in the construction of multi-storey buildings This polymer material is a base of the latest types of polyethylene Thanks to the improvement of the chemical structure of the molecule and the expansion of polymerization capabilities, today it is possible to obtain polyethylene materials with long hydrostatic resistance at elevated temperatures

The first pipes of European manufacturers made of PE-RT entered the Russian market in the mid-1990s To date, there are many domestic manufacturers using this material in our country Despite the fact that PE-RT has not yet become a common phenomenon in the domestic market, the interest of profile companies in it increases every year Given the characteristics of PE-RT and the increase in the production of products from it by domestic enterprises, it is safe to say that the trend of replacing the more familiar pipes made of steel, polypropylene and PEX will only increase over time

Comparison of PEX and PE - RT pipes

Pipes used today must be resistant to high pressure and high temperatures Ordinary polyethylene (PE) can not boast of heat resistance, because it consists of non-bonded hydrocarbon molecules When such a material is heated, its two-dimensional structure begins to change, which leads to the appearance of plasticity To improve the mechanical strength, polyethylene pipes are " sewn together» "Cross-linking" refers to the formation of longitudinal and transverse bonds between the molecular chains of the material, due to the reaction of carbon and hydrogen atoms located next to the molecules The number of cross-links created in polyethylene is determined by such a parameter as " degree of cross-linking» Teaming up with each other, of polyethylene molecules form a single three-dimensional macromolecule The resulting material is marked PE-X Today, manufacturers offer 3 types of pipes made of this material, which differ by the method of "cross-linking", that is, by changing the structure of molecules To obtain them various components are added to the initial raw material:

• PE-Xa-peroxide-obtained by heating under high pressure when adding peroxides The lowest level of linkage according to the norms of DIN 16892 is 70%;
• PE-Xb-silane-obtained under the influence of chemical components, including silane The lowest crosslinking rate is 65%;
• PE-Xc-electronic-the finished product is irradiated with electrons with the formation of multidimensional bonds The lowest crosslinking rate is 60%;
• PE-RT is the latest type of polyethylene used in the manufacture of pipes intended for heating systems, as well as cold and hot water supply systems It was developed as a replacement for obsolete PEX material, due to the inability to weld and re-process the latter, as well as due to its need for cross-linking In this case, PE-RT is an ordinary thermoplastic (like polypropylene material PPRC), which has all the advantages of PEX in the absence of its disadvantages

The ability to exclude the polyethylene crosslinking stage from the technical process increases production efficiency As a result, there is no need to determine the degree of cross-linking, since the properties of the pipes remain unchanged

The temperature required for extrusion makes it possible to process PE-RT on conventional equipment, since this material is excellent for welding even with simple welding units This is why businesses are increasingly abandoning cross-linked PE in favor of PE-RT

Properties of pipes made of PE-RT

PE-RT polyethylene with high thermal stability is an ethylene-octane copolymer with an original molecular structure that makes the material resistant to hydrostatic stress over a large temperature range (from -50°C to +95°C) The main results were obtained in the study of the relationship between the structure and characteristics of polymers, due to the creation of improved technology and the use of catalysts that allow to regulate the process of introduction and location of the comonomer in the main polymer chain The increased reliability of determining the microcrystallicity of polymer materials makes it possible to develop new combinations of their performance characteristics Today, it is possible to produce polymers that are simultaneously heat-resistant, flexible and elastic and have a long flow rate A distinctive feature of the new type of polyethylene is that it does not need to be cross-linked to obtain optimal hydrostatic strength under high temperature loads Thus, the absence of the need for pre-processing of raw materials makes production more profitable than using PEX

Due to the presence of transverse molecular chains PE becomes impact resistant and resistant to cracking when bending It also increases the rate of long-term creep of the material, since a large number of crystallites in it bind to each other Side chains can move and stretch, so they tend to absorb and dissipate energy

Pipes made of heat-resistant PE (PE-RT II) are used in many areas, including:

• in drinking water supply systems;
• in HVAC and DHW systems;
• when connecting radiators;
• when installing a floor heating system

Pipes that supply drinking water must meet the relevant requirements of regulatory authorities for all products in contact with water Pipes must not give the water a specific taste or smell, and must suppress the growth of bacteria In addition, pipe manufacturers are required to disclose the exact composition of their products

PE-RT material fully meets the Russian standards developed for products in contact with water

Pipes made from this material show excellent hydrostatic strength under high temperature loads, and without the need for cross-linking This feature makes this material suitable for the manufacture of DHW pipes The rules for the use and installation of polymer pipes for hot water and heating systems are described in SP 40-102-2000 and SP 60-13330-2012

This material was approved and first added to GOST P-52134 (for 2010), and in the fall of 2015 to the updated GOST 32415-2013

PE-RT can be used for all types of pipes, including pressure pipes, pipes for heating boilers and heating systems They are designed for operating pressures in the range of 2-10 atmospheres and temperatures up to 80°C, and can withstand short-term temperature loads in the range of 95-100°C Requirements for the operating conditions of pipes for different types of DHW are listed in the framework of GOST 52134

Heat-resistant PE has been successfully used for more than two decades in the manufacture of pipes for hot water supply The combination of flexibility and impressive hydrostatic strength under high temperature loads makes PE-RT products the optimal choice for heating and water systems

These pipes are not only very flexible, but also resistant to aggressive chemicals, as well as anti-corrosion qualities PE-RT pipes are easy to install, and the ability to weld them by melting and lightness make it easier to transport and work with them In addition, the lack of need for stitching greatly accelerates the production process, which is of great importance for enterprises that produce multilayer products This type of product allows to provide good hydrostatic strength at high temperature loads, which distinguishes it from ordinary PE of medium and high density used in the manufacture of pipes intended for operation at 40°C

Consider the strengths of the products made of PE-RT:

• transparency of the pipe production process, which consists of a single stage, without the stitching stage;
• the flexibility of the material simplifies installation work;
• since PE-RT is a material with high heat resistance, it fully meets the requirements of GOST 52134 and international standards for heating systems and DHW;
• it is an optimal choice due to its excellent technical indicators

These advantages make PE-RT the most promising material in the production of composite pipes

Types of pipe connections

Fittings made of brass or polymer materials are used to connect pipes made of REX and RE-RT In this case, 2 types of fittings are used: press (having a pressing sleeve) and compression Places of pipe connections must be strong, reliable and absolutely sealed to withstand continuous pressure from the inside Pipes are connected by fittings at connecting sections, at turns and at points of branching Consider the most famous types of pipe connections

Press connection

To obtain such a connection, it is necessary to radially compress the metal-plastic pipe on the fitting using the appropriate tool To do this, you will need specialized pliers that are selected based on the profile of a specific manufacturer Let's look at the stages of connecting a fitting to a pipe

After cutting, the pipe will need to be calibrated, otherwise it will not fit the fitting You will also need to clean it from burrs and remove the chamfer

Then the pipe is carefully put on the fitting of the press fitting, so that the rubber rings are not accidentally dislodged or damaged

Specialized sponges of the corresponding profile are used for crimping the sleeve Such connections can only be pressed by a qualified master who has the necessary working tools and is able to correctly select the profile of the crimping sponges Keep in mind that during installation work, you will need to select suitable profiles for all fittings It is also necessary to know that if the crimping areas coincide with the areas where the rings are placed, the seals will no longer be able to compensate for the temperature deformations of the pipe walls

The press fitting must be equipped with o-rings made of rubber, but over time they become outdated and dry out, which is likely to cause the loss of tightness of the connections Also, the fitting must have a gasket made of a dielectric that protects the aluminum foil from contact with the metal part of the fitting The lack of such a gasket will contribute to the appearance of a galvanic pair, and it, in turn, will eventually cause electrocorrosion

When the fitting is pressed, it will need to be fixed with a sleeve As a rule, such fittings are equipped with a steel, brass or aluminum sleeve

Connection on the sliding sleeve

You can connect pipes using the method of axial pressing, in which the sleeve is pressed on a pre-recessed and stretched on the fitting tip of the pipe When putting on the sleeve, the pipe is pressed closely against the fitting, but since the polymer from which it is made has a "molecular memory", the wall of the pipe continuously tries to return to its original state, which greatly increases the reliability of the connection, which serves as long as the system itself is operated

The ease and clarity of the internal structure of the connection, the absence of the need for seals, dielectric gaskets and welded elements made of non-uniform materials make this type of connection the best option and reduce the cost of production The use of this type of connection when creating pipeline systems involves the use of fittings made of polyphenylsulfone, or brass fittings Flexible and long coil winding, in combination with a variety of varieties and a wide range of fittings, makes it possible to minimize the number of necessary connections and dramatically reduces the amount of waste

The clamping connection is based on pushing the pressing sleeve all the way to the stop, using the appropriate tool after connecting the pipes to each other In this situation it becomes easier to notice the lack of compression For example, when the sleeve is free to fit on the pipe, the lack of compression becomes obvious Then when the test pressure increases, as soon as the system is fully filled, it will instantly leak

It is important to remember that the fitting can be repeatedly remounted, without fear of damaging the construction details, if a serious mistake was made during the installation work For this purpose, you will need to cut out the incorrectly attached component and heat it with a hair dryer to 150°C The fitting freed from the pipe fragments can be used again

Since the ring is strung on a pre-expanded pipe, the resulting joint will have an increased internal cross-section, which is a protection against narrowing and helps reduce hydraulic resistance in the system itself

Consider the strengths of the connections on the sliding sleeve:

• The elements are connected without the use of seals, since their function is assumed by the pipe Thanks to the uniform texture of the pipe wall, compression can be performed evenly, and special ring-shaped notches on the fitting make the connection stronger and more reliable;
• The inner diameter of the pipes remains unchanged, and due to the absence of constrictions, pressure losses are minimized;
• Possibility of multiple correction of installation errors

Connection of pipes "CONTOUR G-Ray" using a sliding sleeve

This type of connection is so simple that it can be performed even by a person who does not have special knowledge and professional skills To do this you just need to have a small set of tools at hand Thanks to a large selection of tool types (manual, electric, battery or mechanical), you can work with pipes of any diameter, including on non-electrified construction sites and even at sub-zero temperatures

PE - RT TEBO ®PIPES AND FITTINGS

RE - RT systemTEVA® it is a patented innovative development in the field of installation methods for pipeline, heating and water systems The original structure of the fittings intended for welding makes it possible to use them when connecting products made of PE-RT II and having an anti-diffuse layer of EVOH inside The developer and patent owner is the Russian company Alter-Plast»

Scope of use of PE - RT pipes TEVA®:

• HVAC and DHW systems;
• low-temperature heating systems

Elements of the PE-RT system TEVO® has the following advantages:

• Highly reliable thanks to complete sealing and solidity of the connections
• They can be stored for a long time, since they do not increase the percentage of cross-linking
• Heat-resistant and designed for operation at a coolant temperature of up to 110°C
• They are frost-resistant, so they can be frozen and thawed several times without losing the original properties of the material
• Resistant to chemicals, so the system can be used for transporting food, gases and aggressive media
• Very flexible and high-strength, since cross-linking is not used in their manufacture
• The presence of specialized fittings makes them easy to install
• No need for regular maintenance
• A wide selection of specialized fittings allows you to implement a variety of design solutions
• The estimated useful life of more than 50 years
• The manufacturer gives a 7 year warranty