Corrugated wire underground. Which pipe is best for laying cables in the ground - an overview of the advantages of different types of pipes

Corrugated HDPE pipes (low pressure polyethylene) is a versatile and very user-friendly product that is suitable for protecting cables. With the help of corrugated pipes, it is also possible to create drainage systems designed to collect and remove water on suburban areato protect the foundation of the building from destruction. Today corrugated pipes have a very wide range of applications - in homes, offices, technical rooms and even underground - they can withstand severe mechanical damage and high traffic loads.

HDPE corrugations - these are hollow plastic channels with a high degree of flexibility, so that during their installation, virtually no additional connections are required. Corrugations can be used for laying new systems and for complete or partial replacement of existing ones.

The pipes presented in our catalog are manufactured by the Russian company Promrukav, which has existed on the market of cable support systems for more than fifteen years. All products of the company are made from safe materialsthat exclude the possibility of fire. The company pays great attention to the presentation and consumer qualities of all its products. HDPE pipes of the Promrukav company do not emit toxic substances into the air at room temperature; working with these pipes does not require additional precautions.

Flexible corrugated HDPE pipes intended for laying open (along the wall, along the ceiling), half-hidden or in a hidden way (in the wall, in the ceiling) television, computer and telephone networks, subject to their implementation insulated wires or non-flammable cords and cables. They are used both indoors and outdoors.

Pipes manufactured by Promrukav during use - stretching, twisting and laying - do not form cracks, they are uniform in thickness along the entire length of the corrugation.

They provide the degree of protection IP55, provided that all network elements have the same degree of protection. The bending radius of the pipe is equal to three outer diameters of the pipe. Due to their lightness, corrugations are easy to install. They are packed in coils from 15 to 100 meters with a diameter of 16 to 63 mm.

The use of pipes for laying cables in the ground allows you to additionally protect communications from external influences. The article will discuss the nuances of this process and the pipes used.

The pipes used, the reasons for their popularity

One of the most popular options for routing wires is to place them in the ground. To implement this method, special pipes are used.

Reasons for popularity:

  • When placed overhead, the cable may suffer from a gust of wind, and the above method does not have such a disadvantage.
  • The underground wire is much more difficult to damage, and there is also protection from external weather conditions.
  • Even if the wire is short-circuited, no fire will occur due to the protection.



There are five types of pipes designed for cable laying:

  1. Polypropylene... This material is plastic and heat resistant. These pipes are easy to shape.
  2. Steel... Such pipes are not used for laying power lines.
  3. High and low pressure polyethylene... This type of pipe is characterized by light weight, strength and long service life, and it also has protection against corrosion.
  4. Asbestos-cement... These pipes are heavy and contain asbestos, which is harmful to the human body.
  5. PVC pipes.



The greatest demand at the moment is for pipes made of low-pressure polyethylene (abbreviated as HDPE). There are a huge number of varieties of such products: smooth-walled rigid, double-walled, corrugated pipes and so on.

Corrugated pipes for laying cables in the ground have high elasticity, as well as heavy weight due to the reinforcing mesh inside. In double-walled pipes, in addition to the corrugation, there is a layer of HDPE.

One of the main advantages of laying a cable inside such a product is that it will be completely hidden from exposure environment... The pipes are durable, the manufacturer claims that they can last up to 50 years. In reality, this period turns out to be higher.

Features of HDPE pipes

Features of the use of HDPE pipes:

  • HDPE pipes have a very simple installation;
  • Corrugated pipes are suitable for laying cables for electrical networks;
  • If the installation is done correctly, then the pipes form a tight connection;
  • HDPE pipes eventually return to their previous linear size. The use of a probe can simplify cable routing.
  • HDPE pipes have a high elasticity index (in more detail: ""). Therefore, they can be used all year round; changes in soil temperature will not affect them.

Double-walled corrugated pipes are optimal for laying signal or power cables. Their use allows you to protect the line from any external influences.



There are two different types of pipes, in the manufacture of which low-pressure polyethylene was used: products that meet the GOST standard, and other products from the secondary market. The second option is of inferior quality. It can be chosen if the budget is limited.

Advantages of HDPE pipes:

  • Long service life (manufacturers claim 50 years);
  • No welding is required to connect individual pipes;
  • Lightweight construction;
  • Over time, the product does not lose its performance;
  • External factors do not have a negative impact on HDPE pipes;
  • Additional grounding is not required to lay the cable in such pipes;
  • Wide operating temperature range - from -25 o C to +70 o C;
  • HDPE pipes do not have a negative impact on the environment, since they do not emit toxic waste or condensate;
  • Low-pressure polyethylene pipes are easily deformable; you do not need to use additional fasteners and connecting parts for laying the line. But it should be understood that in the event of a strong bend in the pipe, the cable will not fit into it.

Types of protective pipes

What are HDPE pipes used for? They are designed to protect the cable from various influences. The soil contains chemical compounds that can harm it. Mechanical damage or stress and stray current are also a danger to the cable.

HDPE products for their intended purpose are divided into electrical and purely technical. The first category includes reinforced corrugated or double pipes. They are distinguished by an increased degree of protection. Purely technical pipes are simpler, they are single-layer, there is no additional protection. But their price will also be lower.



Corrugated pipes for wiring are used to protect telephone lines, electricity networks, and so on. It doesn't matter if AC or DC current flows through the cable. But the voltage should not exceed 1 kV.

The information on the technical characteristics of pipes indicates: colors, markings, dimensions, wall thickness, number of layers, compliance with GOST. Usually, for this type of product, the following pattern works: the wall thickness directly depends on the diameter of the pipe. The larger the first parameter, the larger the second.



In pipes, wall thickness can vary greatly. The minimum value for this parameter is two millimeters. In this case, the pipe diameter is between 15 and 50 mm. And the maximum value is up to 3 cm.Then the pipe diameter reaches 25 cm.

Classification of pipes according to ultimate pressure:

  • Lightweight (allowable pressure - 0.25 MPa);
  • Medium light (allowable pressure - 0.4 MPa);
  • Medium (allowable pressure - 0.6 MPa);
  • Heavy (allowable pressure - 1 MPa).

The cable is labeled according to its performance. You can find it on the "sleeve". Thus, the weight of the product is indicated.

Pipe markings:

  • "L" - easy;
  • "SL" - medium light;
  • "C" - medium;
  • "OS" - medium lightweight;
  • "ST" - medium-heavy;
  • "T" is heavy.

In addition to information about the weight, which directly depends on the strength of the product, the diameter of the pipe with the wall thickness is also indicated. This is the necessary information for laying the cable. For example, if you plan to lay a cable under the ground with a cross section of up to 2 sq. mm, then the radius of the pipe should be in the range from 8 to 12 mm.



Several cables can be laid inside the pipe at the same time (maximum 4 pieces). If its cross section is from 6 to 8 sq. mm, then you need to buy a pipe with a diameter in the range of 20 to 40 mm.

You need to choose a pipe taking into account the number of wires in it. For example, if you plan to run three cables with a cross-sectional area of \u200b\u200b10 sq. mm, then a pipe of the same diameter as for two cables with a cross section of 25 sq. mm.

Let's move on to thicker wires. For cables with cross-sections from 35 to 70 sq. mm, the optimal pipe diameter will be from 40 to 50 millimeters. It should be borne in mind that with an increase in the width of the gap, the size of the sleeve decreases.

Another significant characteristic of a pipe that determines its quality is the SDR indicator. To calculate it, it is necessary to divide the outer diameter of the product by the wall thickness. The higher the value of this indicator, the lower the reliability of the pipe. Therefore, you cannot choose products with a wall that is too thin in relation to its diameter. After all, it will fail faster due to low strength.

Laying technical sleeves on general principle similar to laying electrical hoses. The only differences here are the purpose, as well as the corresponding marking. Technical pipes made of low-pressure polyethylene are designed for laying non-electric utilities in the ground. For example, they can be used to conduct a heat pipe or sewage system.

For the manufacture of HDPE technical pipes, secondary raw materials from processing are used. For example, from products marked "PE 32", "PE 64", "PE 80" and "PE 100". The diameter of such pipes ranges from 2 to 50 centimeters.

Such pipes can be used not only for the removal of technical fluids or sewage water. They are also suitable for the implementation of drainage and reclamation systems, the installation of free-flow water supply and similar communications.

Technical pipes for cables into the ground cannot be bent or deformed, in contrast to corrugated products. Therefore, to create turns, connecting fittings are used: couplings, fittings and adapters. Butt welding or compression fittings is possible for absolute sealing.

You can find out more information about the HDPE pipe from the marking. It will be possible to determine specifications products.

Underground cable laying principle

When laying plastic pipe to lay the cable in the ground, you must adhere to the following steps:

  1. The first step is to check the HDPE pipes. They must be free of any damage. The same applies to the pull-through cable.
  2. In places where the pipe is laid, markings must be applied.
  3. Now you can proceed to digging the recess of the required dimensions for laying the cable.
  4. Then the pipe itself is laid.
  5. And now a cable is being pulled through the pipe. It should not be stretched inside.
  6. The entire structure must be buried with a layer of sand of 10 centimeters and a layer of soil 15 centimeters.
  7. A signal tape can be laid over the embankment. This step can be skipped. The tape will act as a markup.

If the power cable is being laid, then it is preferable not to use adapters and couplings at all. When this is not possible, their number should be minimized. The fact is that adapters and couplings will break the tightness of the pipeline, which is so necessary for the power cable.



Where pipes exit the soil and enter the building, special fittings should be installed. What about the minimum cable size for underground placement? It is best to take not the thinnest wires. For example, a cable with a cross-section of 4 mm or more is well suited.

If the above-described method of laying pipes with a cable is not possible, then horizontal laying is used. For its implementation, drilling is required. Among the advantages of this method is the absence of the need for land work. No need to dig a trench for communications.

To begin with, engineering surveys are carried out. This is the name of the work on studying the characteristics of the soil in the area where construction is planned. Drilling cannot be performed until the appropriate documents are received.

When you have the permission, you can move on to the main part. It all starts with drilling a pilot well. A special drill with a radiating head is used, which easily destroys the soil. When it encounters a void, it fills with liquid. It is designed to cool the drill, and also prevents the earth from falling.

The next stage is the expansion of the well. To do this, a nozzle called a rimmer is put on the drill. Then you can proceed to tightening the pipe with the wire into the well. A drilling rig is also used for this. This is the most crucial stage of the work, it is also the final one.

Cable laying in a pipe under the road

In some situations it is necessary to lay the cable under the road. This is a rather difficult method, which is used when it is impossible to dig a trench. Drilling can be handled by a specialized organization that has the necessary equipment at its disposal.

When choosing pipes, it is necessary to take into account the load that will be exerted on them. If you plan to lay the cable under the road, near houses or industrial facilities, then it is best to choose the most durable products.



It is necessary to fully comply with the rules of installation. In this case, the cable will be maximally protected from the effects of the external environment, and the HDPE pipe will not wear out ahead of time.


The cable is laid in protective plastic pipes when it is necessary to protect the cable from the effects of stray currents, aggressive soils and from mechanical damage. Cable laying in HDPE (PVC) pipes is often practiced when installing power lines.

In the event that roads, pipelines and other communications are crossed during cable laying, the use of a protective plastic pipe is mandatory.

The most common types of pipes used for laying cables in them:

    Concrete

    Reinforced concrete

    Asbestos-cement

    Ceramic

    Cast iron

    Plastic (HDPE, PVC)

The most practical and widespread are HDPE electrical pipes, which are used for both telephone cables and power wires and cables. The popularity of these pipes is due to the low price, ease of transportation (the HDPE pipe is light) and installation, moreover, the HDPE pipes are completely harmless to the environment and humans - they are not toxic and absolutely explosion-proof.



And so, after the type of pipe that will be used for laying the cable has been determined, it is necessary to calculate the inner diameter of the HDPE pipe, suitable for the cable.

How to calculate the nominal diameter of an electrotechnical HDPE pipe for cable laying?

In practice, 2 options for calculating the pipe diameter are used. Let's call these options non-trivial - simple and complex:

    Simple - does not require special calculations and nuances ( cable type, number of wires in one pipe, number and amount of turns, route length, etc.) cable laying. This method, of course, allows for some error in the precise determination of the inner diameter of the pipe for laying the cable.

    Complex - calculations and definitions of the group and ciphers of the complexity of the cable route, taking into account the type of cable, etc.

A simple way to calculate the minimum pipe diameter for laying cables and wires

The calculation is made according to the formula depending on the complexity group of the gasket ( the formula is used when laying one cable in a pipe):

d vn ≥ 1.65 * d cab

Straight sections 100 m; sections of 75 m with one 90 ° turn or two large corners; 50 m sections with two 90 ° corners or three large corners; 40 m sections with three 90 ° corners or three large corners; plots of 30 m with four 90 ° corners or five large corners;

  1. Group II

d vn ≥ 1.4 * d cab

Straight sections 75 m; 50 m sections with one 90 ° angle or two large angles; 30 m sections with two 90 ° corners or three large corners; plots of 20 m with four 90 ° corners or five large corners;

    Group III

d int ≥ 1.25 * d cable

Straight sections 50 m; 30 m sections with one 90 ° angle or two large angles; plots of 20 m with two 90 ° corners or three large corners; 10 m sections with four 90 ° corners or five large corners.

where d vn is the inner diameter of the HDPE pipe, mm, d cab - outside diameter cable, mm

Important: trade organizations and manufacturers electrical pipe PND indicate in their catalogs and price lists the outer diameter of the pipe: 16, 20, 25, 32, 40, etc. Calculating the inner diameter of a pipe is very simple:

d int \u003d d nar - (e * 2),

where d ext is the inner diameter of the pipe, d ext is the outer diameter of the pipe, e is the wall thickness of the pipe.

Example. Technical pipe HDPE 110х8,1 mm

110- (8.1x2) \u003d 93.8 mm

To calculate the inner diameter of a HDPE pipe when laying several cables with the same or different diameters in it, the following formulas are used:

Click to enlarge

where d vn is the minimum inner diameter of the pipe, d cab is the cable diameter (or its maximum transverse dimension), d cab1, d cab2 and n 1, n 2 are the diameters of the cables and their number. For a flat cable, you must substitute its width divided by 2 into the formula.

For a more detailed calculation, which takes into account all the nuances of laying a cable in a pipe, you can use

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