For laying external pipelines for the purpose of transporting the working environment, both to industrial facilities and to the residential sector, pressure pipes made of polyethylene are widely used. All features relating to the characteristics and installation of these pipes are discussed in this article.

PE pressure pipe

Features of PE products

Scope of use

PE pipes are used to transport the working medium, which is:

• drinking and industrial water;
• various gases;
• liquid chemical compounds, which do not affect polyethylene.

The products are mainly used for:

1. Cold water supply.
2. Sewage systems.
3. Transportation of natural gas.

In addition, polyethylene free-flow pipes can be used when installing a protective route for power cable due to its property of not conducting electricity.

Main characteristics

Pressure polyethylene pipes are manufactured using polyethylene, which is characterized high density, the following class:

• PE 100;
• PE 80;
• PE 63.

PE pipes in coils

In order to solve all possible problems in organizing water supply, pipes are produced various diameters from 16.0 mm to 1600.0 mm and are designed to work with a medium under pressure from 0.40 to 2.0 MPa. Products are painted black and marked with blue stripes. Products are supplied in straight lengths of 12 m or other standard length. At the same time, polyethylene pressure pipes less than 110.0 mm in diameter are supplied in coils with a length of 50 m to one kilometer.

Despite the fact that polyethylene pipe products mainly used for transmission cold water, the operating temperature range of operation of the products is plus 40ºС. Therefore, it is quite possible to use pipes (made of special high-tech polyethylene) to organize heating or hot water supply systems. For sewerage, non-pressure coupling pipes made of polyethylene are more often used.

Advantages

Polyethylene products are in constant demand. Their popularity is due to many positive features, when compared with cast iron and metal products. First of all, they are characterized by:

• more long period operation. Guarantee period polyethylene pipes defined at 50 years;
• non-susceptibility to corrosion when transporting water and aggressive chemical working environments;
• very light weight, which reduces the cost of transporting products;
• convenient delivery in coils, thanks to which they are reduced Consumables and the installation efficiency is significantly increased;
• the presence of several methods of connecting pipes, including butt welding.
• the ability to repeatedly dismantle and re-lay the pipeline at minimal cost;
• ease of disposal and recycling of products;
• high elasticity, which greatly facilitates the installation of pipelines of any configuration;
• ability to withstand variables ground loads, including earthquakes. For laying in the ground, the products do not require additional protection;
• smooth inner surface;

Thanks to this design feature it is possible to use pipes with a smaller diameter, while providing the necessary hydraulic properties. The throughput of PE pipes is 15% higher than steel pipes.

• low elasticity of the material, therefore, polyethylene water pressure pipes are not subject to water hammer;
• resistance to low temperatures (when the working medium freezes, the pipe does not collapse);
• environmental cleanliness and bacteriological safety.

Installation of PE pipes

Types of connections

Reliable connection of products can be carried out in several ways:

1. Butt welding.
2. Using special couplings with embedded electric heaters.
3. Using flange connections.
4. Using the bell method.
5. With the use of an expansion coupling.

Flange and socket connections are detachable. The remaining connections cannot be disconnected.

Butt welding procedure

This method is used to connect polyethylene pipes with a diameter of 63.0 mm or more. To obtain a reliable joint you must:

1. Fix the parts that need to be welded in a special butt welding machine.
2. Clean the ends of the pipes from dirt and dust.
3. Treat the surfaces of the products that are planned to be welded with a facing device.
4. After obtaining uniform chips (no more than 0.50 mm thick), check the mutual parallelism of the pipes.
5. By using heating device heat the ends of the parts until the surface of the pipes begins to melt.
6. Close the melted surfaces and gradually increase the clamping pressure.
7. Wait some time for the seam to completely weld and cool.

Butt welding

Welding with electric couplings

Although this method is more expensive, since it requires special couplings containing electric heating elements; it is widely used in conditions where it is impossible to perform butt welding due to limited space. This technology is not used for pipeline products large diameter.

The technology for performing the procedure is as follows:

Modern devices ensure that the entire welding cycle is carried out independently with guaranteed quality. In addition, all information on the operation is documented in an electronic protocol.

Thus, polyethylene pipe products are optimal and sufficient effective option for organizing a water supply or sewerage system.

Since the installation of polyethylene pipes is enviably simple, and they themselves are extremely attractive in price, durability and reliability, their use is becoming increasingly widespread in comparison with other materials. They are used not only in industrial, but also in household, are ideal for use in sewerage, heating, gas and water supply systems.

For more quality installation pipes, you must adhere to some recommendations that will be presented in this article.

Necessary tool

To install polyethylene pipes with your own hands, you will need the following tools:

• soldering iron;
• pipe cutting scissors;
• gas keys.

As a rule, it is equipped with a set of attachments with different diameters.

In extreme cases, scissors can be replaced with a jigsaw. But scissors are more convenient - when cutting pipes, they produce smooth edges without nicks or burrs.

Connecting polyethylene pipes will require the use of a gas wrench.

To ensure that the pipe connection is as reliable as possible, a flax sealant is used - such connections have the advantage of always remaining dry. Tools for installing polyethylene pipes can be purchased at almost any hardware store.

Often, a soldering iron with nozzles and scissors are sold as a set - you don’t have to look for them specifically.

Pipe installation

Where should you start?

Features of preparation and installation of polyethylene pipes:

• Quantity necessary materials calculated depending on the length of the route, the number of corners and differences.
• Before starting installation, you must turn off the water supply, then prepare the materials in accordance with the project, after which you can begin installation.
• If in the home heating system, the laying of polyethylene pipes should be done starting from the boiler.
• After the dimensions have been determined, the cuttings of connecting fittings and are soldered together. Also, using a soldering iron, polyethylene pipes are connected.

Learning how to use a soldering iron yourself is not that difficult. Of course there are many technical nuances, which are included in the installation of polyethylene pipes - the video on our portal will help you visually visualize the described manipulations.

Welding installation technology

Installation of polyethylene pipes is as follows:

All connections should be carefully inspected for leaks. After inspection, if everything is in order, the required pressure is set on the boiler and air is bleed from the radiators.

Fittings for polyethylene pipes

If PE pipes are chosen as the material for the construction of the pipeline or polyethylene pipes are to be repaired, fittings will be required to connect them. Depending on the method of their installation, fittings for polyethylene pipes are divided into several main types depending on the installation method.

Exist the following types connections of polyethylene pipes:

• welding of PE pipes;
• pipe gluing;
• threaded mechanical connection.

Types of fittings depending on the method of pipe installation:

1. Fittings for polyethylene pipes, electric welded are equipped with embedded heating elements.
   If the wire is heated using electricity to a certain temperature, the polyethylene begins to melt, resulting in the formation of a uniform, tight connection where the transition for polyethylene pipes is made from one section of pipe to another. By using modern equipment for welding polyethylene fittings, it is possible to set the voltage and time necessary for high-quality welding.
2. Compression fittings. In principle, they are practically no different from those used in the installation of plastic or copper pipes.
   The only difference is the material of manufacture. They are extremely convenient to use, since no preparation or qualification is required - the fitting is completely ready for installation on pipes.
3. Butt welding. Performed using spigots - PVC fittings without the use of an electric spiral..
   The principle of connection is to heat the ends of the pipes until the material becomes viscous, after which they are connected under pressure. If the welding technology is followed, the connection point becomes homogeneous with the pipe.
4. Reducing fittings used when welding pipes of different diameters - they have threaded connection for better installation.
   Threaded fittings are also used for connections when installing PE pipes with water distribution equipment, meters, and so on.

Based on these data, we can conclude that correctly selected fittings allow you to install polyethylene pipes for a water supply or heating system with your own hands, without exerting excessive effort and without requiring special training.

LOCAL RESOURCE DISTRIBUTION GESN 34-02-003-01

PRICE VALUES

The price indicates the direct costs of work for the period 2000(Federal prices), which are calculated based on standards 2009. The conversion index to current prices must be applied to this value.

You can go to the pricing page, which is calculated based on the 2014 edition standards with additions 1
The basis for use in calculating labor costs and material consumption is GESN-2001

LABOR COSTS

CONSUMPTION OF MATERIALS

TOTAL PRICE: RUB 32,721.86.

Used in systems whose maximum operating pressure is no more than 0.16 MPa.

Low pressure polyethylene pipes are simple and easy to install.

Not long ago, the main products in gravity system drainage and sewerage, both industrial and domestic, pipes made of various materials. Along with asbestos-cement products, reinforced concrete non-pressure products were also actively used.

But this area of ​​water supply and sewerage began to be actively conquered by non-pressure polyethylene pipes.

The main factors that significantly influence the choice of low-pressure polyethylene pipes are their highest performance qualities:

• no corrosion;
• excellent resistance to various chemicals;
• long service life;
• simplicity and ease of installation;
• relatively low cost.

Three types are produced for water supply and sewerage:

• non-pressure smooth HDPE pipe;
• non-pressure corrugated HDPE pipe made of polyethylene;
• spiral free-flow pipe.

Free-flow smooth pipe

Gravity connection smooth pipe clamp fittings.

Smooth non-pressure polyethylene pipes have Orange color and are produced in sizes:

• diameter from 20 to 560 mm;
• length from 500 to 1300 mm.

Types of products based on the ring stiffness class:

• SN2 - installation depth no more than 1 meter;
• SN4 - installation depth no more than 6 meters;

Installation of this product is carried out in a socket. One side of the HDPE pipe has a socket in which it is located. Installation of sewerage is very simple; to do this, you need to insert one product into the socket of another. If it is necessary to connect elements with different diameters, there are special adapters for this. For ease of installation, there are various tees, couplings and corners.

It doesn't cause any problems either. Ceiling or wall mountings are made using simple latches (clamps), which are fastened to the wall or ceiling with screws.

Corrugated non-pressure pipes

Installation of sewerage is very simple; to do this, you need to insert one product into the socket of another.

This type of HDPE pipes is also used for sewerage and drainage systems. This type of free-flow pipes can be made from polyethylene, polypropylene and a combination of both.

Polyethylene pipes of this type have differences in design and production technology. These products are produced in a two-layer version and have a smooth inner surface and a corrugated outer surface. The outer wall of the product, which is black, guarantees high protection from ultraviolet radiation; it also serves to ensure the necessary annular rigidity of the HDPE pipe and its resistance to deformation. White color, which has an internal wall, facilitates visual diagnostics of the sewer system.

This product is available with the following classes of ring stiffness:

• SN4 - installation depth no more than 4 meters;
• SN6 - installation depth no more than 6 meters;
• SN8 - installation depth no more than 8 meters;
• SN16 - installation depth no more than 16 meters.

Available in sizes:

• diameter - from 110 to 1200 mm;
• length - 6 or 13 m;
• profile width - from 6 to 41 mm;
• wall thickness - from 1.2 to 5 mm.

Here are some positive factors:

The rubber gasket is installed inside the corrugation, which prevents it from moving during installation.

1. High impact resistance (even at low operating temperatures).
2. Good resistance to chemical and mechanical stress.
3. High ring rigidity as a result of the use of special grades of polyethylene and optimal design in production.
4. Ease of installation: the connection is made using a rubber gasket (O-ring) and a coupling or butt welding. The rubber gasket is installed inside the corrugation, which prevents it from moving during installation. Thanks to its special shape, the rubber gasket prevents not only leakage from the product, but also groundwater from entering it.
5. High versatility due to the possibility of application wide choice fittings, which allows you to connect to any type of pipe.
6. The low weight of the product allows it to be conveniently stored, mounted and transported.
7. The excellent flexibility of the product makes it possible to easily bypass various obstacles when laying a pipeline system.
8. Long service life at low operating costs.
9. Excellent value for money.

Features of installation and installation

For pipes with a diameter of 250-1200 mm sealing ring inserted into the groove of the first groove.

This product is intended for underground installation with a maximum depth of up to 16 m and a minimum depth of at least 1 m. It is very important to choose the right material for backfilling the formed trench. The granulometric composition of this material should densely fill the corrugated products, that is, the particle size should not exceed the width of the profile.

A connection using an o-ring and a coupling is performed as follows: for a product that has a diameter from 250 to 1200 mm, install the o-ring in the groove of the first corrugation. For a product that has a diameter from 110 to 200 mm, in the groove of the second corrugation. After this we install coupling, and the force must be constant and equally distributed.

One of the important advantages of corrugated free-flow pipes is that they can be connected using butt welding. This became possible due to the sufficient wall thickness and the distance between the corrugations. Performance welding work is a complex process that should only be performed by an authorized and qualified professional. However, it should be remembered that butt welding is used to seal pipes and cannot provide the same ring rigidity as a coupling.

Spiral free-flow pipes

Thanks to geometric shape pipe wall profile, spiral pipes have the highest resistance to deformation for free-flow networks.

A spiral-shaped non-pressure product is used for the construction of a non-pressure sewerage and drainage network, often of large diameter (more than 1000 mm). This type gravity pipe made of polyethylene by winding a continuously produced profile onto a rotating drum cylindrical with simultaneous welding of the turns together. Due to the geometric shape of the pipe wall profile, it has the highest resistance to deformation.

This product has several types:

1. SPIROLINE has ring stiffness SN2, SN4, SN6, SN8, SN16, which allows its installation to a depth of up to 16 m. A wide range of internal diameters - from 500 to 2400 mm. The length of the segment is from 0.5 to 13.5 m.
2. KORSIS has ring stiffness SN4, SN8, which allows it to be laid to a depth of up to 8 m. The internal diameter is from 800 to 2400 mm. The length of the segment is from 0.5 to 13.5 m.
3. VEHOLIGHT has ring stiffness SN2, SN4, SN8. Inner diameter - from 280 to 800 mm and from 360 to 3000 mm. The length of the segment is from 0.5 to 13.5 meters.

The connection is made by directly screwing one product into another with further end welding. These polyethylene pipes can also be installed using different shaped elements (bend, transition, tee, tank, well).

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Construction of a pipeline from polyethylene pipes

Most of all pipelines laid in cities date back to Soviet times. The deterioration of heating mains, sewerage, gas and water communications reaches 70%, which is due to the material from which the pipes are made. This is steel that is subject to intense corrosion. The construction of gas pipelines from polyethylene pipes is becoming more in demand today. As the service life expires, many accidents occur on various pipelines: under high pressure Pipes break, numerous leaks form, which lead to significant water losses. Performance indicators deteriorate: by reducing the cross-section of pipes, their throughput is reduced, the water becomes polluted, and its biological indicators decrease.

Advantages of polyethylene pipes

Pipes made of polyethylene (PE) are a modern alternative to their physically and morally outdated metal predecessors. They have whole line undeniable advantages compared to products made of steel or cast iron.

1. No corrosion, which minimizes installation, maintenance and repair costs.
2. Ease of use: polyethylene products are easy to cut, so they can be easily adjusted to fit construction site, and in field conditions when laying pipelines.
3. High throughput due to the fact that the inner walls of PE products are smooth.
4. Polyethylene pipes have an elastic structure internal walls, on which scale does not form as a result and they are not clogged from the inside by various suspensions contained in the liquid.
5. Polyethylene is chemically inert, successfully resists aggressive influences, therefore, it does not require additional special protection.
6. Polyethylene is not electrically conductive, so it is not afraid of stray currents that destroy metal pipes.
7. The bending radius of a polyethylene pipe can be up to 10 of its outer diameters, depending on temperature, which reduces costs connecting parts and facilitates pipeline design and construction.
8. Polyethylene pipe has high flexibility: the minimum bending radius is 25 pipe diameters at 200°C.
9. Significantly less weight compared to metal pipes, which facilitates installation and installation.
10. PE pipes are resistant to temperature changes and have high sanitary and hygienic characteristics.

Scheme of deformation of polyethylene pipes depending on the type of soil.

Important note. Freezing of the soil leads to the movement of pipelines into vertical plane. These movements are uneven, resulting in deformations (bending). Predicting these conditions, it is necessary to determine how much the bending radius of a polyethylene pipe depends on the level of temperature reduction. In order to determine the bending radius, it is necessary to make special calculations. Or refer to special tables that indicate the minimum bending radius for specific type pipes

The minimum bending radius of a polyethylene pipe is recommended by the manufacturer for each type and grade of pipe. If it is not possible to obtain the required bending radius, then bends, tees, etc. should be used.

Thanks to its technological and operational characteristics polyethylene pipes received wide application: they are used in the construction of new pipelines and in the repair of old communications that have expired.

Scope of application of polyethylene pipes

Polyethylene products are widely used in modern construction.

They are used in the construction of water supply, sewerage, and gas pipelines. PE pipes are used in pressure and gravity sewers and serve as protective cases for electrical and telephone wires.

Old networks are being reconstructed using polyethylene pipes. Replacement can be carried out with the destruction of worn-out communications, but it is possible to lay new ones in parallel with the old ones, which does not require stopping the water supply to the population and blocking the sewerage system. Reconstruction of wells and other communication and plumbing structures depends on the degree of their deterioration. May be subject to partial replacement individual parts(neck, shut-off valves etc.), if necessary, is carried out major renovation with complete replacement of pipelines.

Installation of polyethylene pipes for sewerage

Sewage networks are internal and external. Their purpose is to collect and transport sanitary and stormwater waste water, having different chemical composition. Any problems in the sewer system dramatically affect the quality of life.

Elements and assembly for polyethylene pipes internal sewerage

Polyethylene pipes for sewerage began to be produced not so long ago, and today they fully meet high requirements due to their inertness to the effects of mineral acids, alkalis and other aggressive substances. PE sewer pipes have a large throughput due to the absence of internal roughness. When settling in external systems sewer systems use frost-resistant PE pipes. Installation of internal sewerage does not require pipes with such high performance characteristics.

Sewage pipes are attractive to specialists working on the installation of such systems because their installation is much simpler compared to traditional sewer networks. Installation of internal sewer lines when using polyethylene pipes does not require complex special equipment. Small diameter polyethylene pipes are mounted using compression fittings.

Equipment external sewerage produced by butt welding: special welding equipment allows installation, reducing the number of joints up to five times in comparison with metal sewer pipes

Connection of water supply polyethylene pipes

PE products are connected in three main ways:

1. contact- butt welding,
2. sleeve welding with embedded electric heaters
3. installation using compression fittings.

It's also possible plug connection, which is carried out by steel clamping flanges. Installation of pipeline turns and branches is carried out using welded or cast fittings.

Different connection methods are used depending on operating conditions. If there are conditions for placing welding equipment, then butt welding is necessary. Butt welding is used when working with large diameter pipes (from 630 mm).

Limited working space (wells, chambers, trenches) requires electrofusion welding using embedded heaters.

If necessary, connect pipes with a diameter of up to 63 mm, use compression fittings what creates detachable designs. This connection It is easy to operate, has high performance indicators, and does not require complex special equipment. Compound internal systems pipelines are most often carried out in this way. Their installation is accessible even to non-professionals.

Pipe laying

Laying polyethylene pipelines is carried out in two main ways. This traditional styling pipes into an open trench and trenchless installation - a method of deep directional drilling.

Using the open method, polyethylene pipelines are laid in a trench, the width of which is determined by the need to create working conditions. Water supply and sewerage equipment requires a trench width 40 cm greater than the outer diameter of the pipeline. These parameters are most often specified in the project. Long polyethylene pipes are often laid in a trench dug using a narrow-section chain excavator. In this case, the width of the trench decreases.

The trench must be properly prepared. Its arrangement depends on the condition of the soil. If the bottom of the trench is hard and dense, then a cushion is needed. The bottom is covered with a layer (about 10-15 cm) of sand or other granular material and leveled. At a distance of 2 meters from manhole the pillow is compacted. There should be no stones or lumps of frozen soil at the bottom. When working with loose soil that is at risk of displacement, it is necessary to strengthen the bottom. In such cases, the bottom of the trench is strengthened with geotextiles.

With a flat trench bottom optimal characteristics There is no need for a soil cushion. You can get by with a small excavation of earth at the base of the pipe to its width and replace it with a softer one.

Backfilling the trench

The soil removed during the construction of the trench, which does not contain 20 mm stones, is used for primary filling. It is made along the entire length of the pipe, about 15 cm high from its top. If it is necessary to compact the pavement, the soil must meet certain requirements. You can use fine gravel (20-20 mm) or crushed stone (4-44 mm). Soil must not be dumped directly onto the pipeline. The pipeline laid at the bottom of the trench and sprinkled needs to be compacted. The filled soil is compacted in layers of 20 cm on both sides of the pipe so that it does not move. The soil is not compacted directly above the pipe.

Backfilling is done after compaction and a compacted layer of about 30 cm on top of the pipe. The trench can be backfilled with extracted soil; the maximum size is allowed large stones no more than 300 mm. Even with a layer of protective pavement about 30 cm thick, the size of the stones in the soil used for backfilling cannot be more than 60 mm.

Trenchless pipeline laying

In some cases, when pipeline lines intersect with a railway, busy highway, river or other obstacle, laying an open trench is not possible. The reason may also be the need to minimize the cost of digging a trench. This is the basis for using the method of trenchless laying of polyethylene pipelines. The method of trenchless installation of horizontal directional drilling (HDD method) has become widespread.

Horizontal drilling is a special method of installing communications without opening the soil. Work begins at the point where the pipe comes to the surface. Technology guarantees high accuracy bringing the drill out to the expected location of reaching the surface. The method makes it possible to lay underground pipes with a length of more than 100 m and a diameter of up to 630 mm or more. There are two main methods of horizontal drilling: guided and unguided.

Controlled horizontal drilling is carried out by tunneling machines, through flushing and pilot drilling.

Uncontrolled horizontal drilling is carried out using two methods: 1) without casing (ram rocket, displacement drilling, auger drilling) and 2) with casing pipes(drill injection, puncture drilling, impact drilling, ram drilling).

Horizontal drilling methods and trenchless laying of polyethylene pipes are considered the most modern technology. To enlarge the well, a special drilling enlargement is used. To improve drilling, the well is treated with a drilling clay mud, which forms and lubricates the channel itself.

Thus, the characteristics of polyethylene products allow them to be installed and laid using any currently known method, taking into account the restrictions imposed by the minimum permissible radius of their bending.

A polyethylene pipe that is pulled or pushed is able to repeat the configuration of the old route, which has a radius of curvature of more than 120 diameters of the pipe itself. Metal products practically do not have such a bending radius.

Organization of installation work

Welding is carried out either by basic scheme, or by the route method. The basic method is used in cases where the facility is located close to the welding site, where the pipes are pre-connected and then transported in finished sections to the pipeline route. The length of the section can reach more than 30 m. On site they are welded into a single thread, which must then be carefully laid in a trench so as not to disturb the bending radius.

Route welding begins along the trench. Then installation and welding is carried out using mobile welding units. Small diameter pipes can be laid in the trench manually. However, pipelayers or cranes are most often used. The finished thread should be lowered without jerking, evenly, having previously secured it hemp ropes or soft slings, which should be located at a distance of 5-10 meters from each other. The solid welded thread must be lowered into the trench carefully so that the critical bending radius is not exceeded during installation. You should first wait at least 2 hours after welding the last link.

Disadvantages of polyethylene pipes

Problems with polyethylene products are related to the characteristics of all viscoelastic thermoplastics. Their strength largely depends on the degree of bending and compression, and in general it is relatively small. Polyethylene is sensitive to ultraviolet radiation, which has to be compensated for by coloring additives (usually carbon black) and the use of protective painting. The thermal expansion of polyethylene is quite high and has to be compensated for using a structural L- or U-shaped bend of the pipe.

Today domestic underground pipelines have a length of about 2 million km. These are mainly steel pipelines. For example, polyethylene pipes account for about 10% of the total length of gas pipelines. Other networks also do not have very high scores for this parameter. However, there is a strong tendency that modern pipelines in percentage are changing in favor of polyethylene pipes.