PND pipes for cable. PNDE TEPERIC FOR CABLE

Work on the laying of communications is always associated with the risk of their subsequent damage. In other words, the wiring can damage both the soil and builders, with the inactive performance of work. As a warning of such cases, a special HDPE tube was created, which is designed to protect it and secure people from electric shock.

The first and most basic feature is that the electrical was created from dielectric materials. That is, it serves as an additional protective layer, which is designed to protect others and the cable itself from dangerous, extraneous influences.

Also, the design of the product allows you to protect the cable from mechanical damage during operation. What guarantees an increase in the term of use.

Additionally, it is worth noting that for different types Styling, various products are applied. For example, when stretching power cables in air, a corrugated-type PND tube is used, without additional reinforcement and amplification - this makes it possible to minimize the weight of the design and reduce the load on the suspended elements. The main purpose of such protection is to minimize the ultraviolet flow, which is able to destroy the insulating layer.

For underground strip Communications, PND pipes high strength are used, often with additional reinforcement. This is necessary to effectively confront the pressure of the soil and other factors, for example, the inaccurability of builders (often, cables hide buckets of bulldozers when performing land).

Advantages of using PND pipes

Pipe under polyethylene cable low pressure It has a number of features, thanks to which its use is optimal for various laying methods. Below is a list of basic advantages.

Low cost is this kind of much cheaper than traditional materials.
The low weight of the PND products is much less metallic.
Long service life - more than 50 years.
High flexibility. The materials used have increased resistance during bends, but it is impossible to forget about the possibility of broaching the conduct of wiring. With too strong inflection, the wire will not be able to mount correctly.
Providing sufficient technical opening to add new postings.
Easy installation.
PND housings relative to small diameter do not require spikes at the ends, which lowers the need to apply complex equipment.
Not subject to corrosion, aging.
High resistance to significant temperature drops.

This is not a complete list of significant advantages to apply these materials.

Advantages of corrugated pipe

Is one of the most popular building materials facilitating the gasket of communications.

As a means of increasing reliability and comfort of installation, additional reinforcement of steel wire can be used - it gives it an additional ring rigidity. The corrugation thus reinforced can be perfectly withstanding the pressure of several soil meters and is great to resist natural factors.

Also corrugated covers are bilateral. The inner surface is smooth, provides good slide while stretching. The outer part is corrugated, gives significant indicators of stability to aggressive environments.

A separate mention is worthy of a feature of corrugated products, take any form, as well as their good elasticity. For example, metal protection can be overwritten and burst in the place of the application of force, which will lead to the penetration of moisture to the wiring, and this is not - it will simply bend, but the integrity is not to break. This is the possibility of laying non-linear channels, which is especially useful in the constraint of space or specific construction conditions.

Maximum efficient is the use of sophisticated soils, such as - stony, seismic or moving soils.

It should be noted resistance to temperature drops. Optimal indicators for mounting is the temperature from - 20 to + 70 ° C.

Types of technical pipes PND for cables

Laying any engineering communicationsconnected with electrical wiring requires impeccable execution, strictly prescribed norms and rules. Usually, the PND tube technical for the cable is selected exclusively for certain operating conditions. The retreat from the requirements may be fraught with serious consequences.

Such trunk channels are divided into technical and electrical. These types are distinguished by the application area, appointment, as well as technical indicators.

Smooth technical pipes PND for cable

PND smooth pipes for electrical work are manufactured using secondary raw materials, which significantly reduces production costs, and minimizes malicious effects on environment. As a negative factor, this technology changes the characteristics and color of the final product, however, it slightly affects the performance indicators.

The scope of this type of pipes is quite specific - they are usually used for the distribution of communications along walls or floors of the room.

In practice, it looks like this: PND The pipe electrical smooth is mounted into the wall stick or the base of the sexual screed. Further, the ends of the highway are displayed, after that, the shit closes. Thus, a free channel for wires, communications is formed. The final stage is performed broaching the power cores, covert the extra edges, the control plugs that serve to compact the conclusions are installed.

Electrical pipes

The second common type is often used as an underground pipeline, laying power and communication cables. The main use lies in the use of cables to 1 kW power.

A special, corrugated design allows the PND pipe to withstand heavy loads, which is an indispensable factor with similar works.

Noteworthy. Each shell has its purpose - external, is a reinforced body and serves as a solid basis for maintaining the shape of the product. Interior, created from the material of another type. It is smooth and plays the role of the sliding layer, to relieve the pulling of the wires.

Also, the design implies separation on pipes with a probe or without it. Directly probe, is intended to facilitate the pulling of wires through the pipe, usually it looks like a steel vein to which the wire is attached. Then, by pulling the flock, it is replaced by the wire.

Important! Despite the significant resistance to mechanical loads, it is not recommended to lay a CIP type wire in PND pipe. This can provoke a decrease in its term of use, as well as lead to an accident.

Technical parameters of pipes

In the manufacture of any type of sleeves, mandatory condition It is strict adherence to all requirements and characteristics. These requirements are clearly defined in certain documents. For example, GOST 16338 defines the requirements for the manufacture of low pressure with labels 271, 273, 276, 277, and 286. And GOST 16337 refers to products, marked as - 10803-020, 15303-00315803-20, 16803-170 .

Additionally, disruption of the integrity of layers, fuses, cracks, or other material defects is not allowed.

Important! The emergence of roughness on the inner walls is not allowed. There is also no violation of the uniformity of the outer layer, both on corrugated and smooth PND pipes.

Sortment of technical pipes PND

	SDR9.	SDR11.	SDR13,6	SDR17.	SDR17,6	SDR21	SDR26.
External. Diameter	Wall thickness product in mm
16	2,0
20	2,3	2,0
25	2,8	2,3	2,0
32	3,6	3	2,4	2
40	4,5	3,7	3	2,4		2
50	5,6	4,6	3,7	3		2,4	2
63	7,1	5,8	4,7	3,8	3,6	3	2,5
75	8,4	6,8	5,6	4,5	4,3	3,6	2,9
90	10,1	8,2	6,7	5,4	5,2	4,3	3,5
110	12,3	10	8,1	6,6	6,3	5,3	4,2
125	14	11,4	9,2	7,4	7,1	6	4,8
140	15,7	12,7	10,3	8,3	8,0	6,7	5,4
160	17,9	14,6	11,8	9,5	9,1	7,7	6,2
180	20,1	16,4	13,3	10,7	10,2	8,6	6,9
200	22,4	18,2	14,7	11,9	11,4	9,6	7,7
225	25,2	20,5	16,6	13,4	12,8	10,8	8,6
250	27,9	22,7	18,4	14,8	14,2	11,9	9,6
	12,3	10	8,1	6,6	6,3	5,3	4,2

Also additionally PE pipes are separated by nominal pressure.

Easy electrotechnical - 0.25 MPa.
Solid - 0.4 MPa.
Average - 0.6 MPa.
Heavy - 1 MPa.

The devices of non-standard type are manufactured individually for the requirements of the customer.

Marking of pipes for installation of the electrocable

Manufacturers carefully follow the need to apply marking. Such designations allow you to clearly define affiliation to any type of work, and also indicates specifications.

The first and important difference is the lack of a special color strip over the entire length. Typically, such a markup is applied only to plumbing and. In addition, the quality mark and the identifier of the manufacturer must be applied to which one can determine who and when released the product.

There are also weight marks that are comparable to their strength.

T - heavy;
St - medium severity;
OS - medium lightweight;
Sl - medium lungs;
L - lungs.

Following, the number of the generally accepted standard is applied, the cross section is indicated, the thickness, number of the layers of the wall and the nominal pressure.

Usually the pipe electrical PND PE for laying the PE type cable PE 63, 80 and 100 is marked as MRS6,3 and 8, 10.

How to choose pipes for cable laying

To properly choose the PND pipes for wiring, it is necessary to take into account the generally accepted values, as well as the number of wires laid in them. For accurate definition The diameter of the PND technical pipe for a cable of different sections is used Table:

Calculation of the number of cables in the pipe

Wire section (sq.mm)	The diameter of the PND sleeves - mm.	The number of transmitted cables - pieces.
95 or more	63/63	3/2
70	63/53/63	3/2/4
50	50/50/63/63	3/2/5/4
35	50/40/63/50	3/2/5/4
25	40/32/50/50	3/2/5/4
16	32/32/40/40	3/2/5/4
10	32/25/40/32	3/2/5/4
6	25/20/32/32	3/2/5/4
4	20/20/25/25	3/2/5/4
2,5	16/16/25/20	3/2/5/4
1,5	16/16/20/20	3/2/5/4

Thus, it should be understood that the number of intended veins, the flow cross section increases.

Methods and rules for laying pipes PND

Depending on the location, methods and rules for laying sleeves from plastic low pressure, they differ radically. Therefore, it is necessary to consider each type separately.

Laying pipes inside buildings

At the stage of draft work, the wall is strokes and placed in it pipes for broach

Usually when installing hidden wiring, is taken for cable smooth or corrugated pipe - it is not prohibited technical standards or gostas.

For wall mountedThe most convenient to use smooth pipes, for sex - corrugated.

The principle and sequence of actions is shown below.

Marking of the required location is made.
Fixation is performed, in the wall on the clamp, in the floor-metal brackets.
The wire is pulled by a special probe or.
Next, the sexual screed is poured or the shock is closed in the wall.

Important! When mounting the wiring, the cables are not allowed, you need to give a little slack, for the possibility of shrinkage.

Methods of laying in the ground

The underground laying technology of PND pipelines is very relevant in modern realities. This method allows you to securely cover the veins and ensure the neat look of the construction.

Separately, for the cable laying in the ground, the methods opened below are used.

The trenchless way of laying in the ground

This type requires special attention and terrorism from builders. In view of the emergency labor intensity of the process, it is extremely rare, only in the urgent need.

The essence of the method lies in the drilling of the horizontal well on which the communications will then occur.

Before performing work, a special resolution is obtained, the composition of the soil is analyzed.

So, to place the cable in the pipe underground, you must perform whole line Mandatory actions. The principal sequence of the operation is shown below.

A pilot well is closed. This is done by a subtle brown for the mark of the main trajectory.
The pilot hole is expanding to the required diameter.
PE sleeve is delayed in the passage.
Mounted cable.

The main minus technology is the considerable complexity and complexity of the process.

Laying on the street in the trench

Cable designer

The gasket of the electrocabilities in the trench is the simplest on the part of technical feasibility. After selecting the necessary wiring and pipes for laying the PND pipeline underground, such a sequence of actions is performed.

The markup of the site is performed.
A trench of suitable sizes are digging.
Checklings are locked.
The sleeve stretches the wire.
The sandy layer is further applied, about 15 - 20 cm thick.
There is a complete trench instillation.

Important! Immediately before installation, the wires must be carefully studied for disruption of the integrity of isolation.

Mounting cable under the road

When it comes to montage under the road site, it is necessary to coordinate actions with local authorities.

There are two methods of this operation.

Trenchless way.
Trench method.

The first type is described above, so do not deepen.

Regarding the second type there are several specific requirements, which are said later.

The depth of the trench should not be less than 1 meter. This is associated with a large load on the ground.
Mandatory placement of indicative elements to prevent accidental break.
The veins are located at a distance - at least 10 cm from each other.

Subtleties laying technical pipes

Depending on the individual characteristics of the laying method of the polyethylene tube. There are several subtleties that need to know in advance.

Installation works can be performed at temperatures up to - 25.
With a trench method, if the depth of occurrence exceeds 2 meters, additional protection is provided in the form of a horizontal mine, which is created from concrete or brick.
Concreting horizontal wiring is allowed.
Mandatory sealing of compounds underground.
In cases of presumptive formation of condensate, measures are provided for its removal.

Outcome

Using high-quality materials, it is possible to significantly extend the service life of communications. Using PND profile for this type of work, significantly reduces the costs of resources and time for their maintenance, and also guarantees security for others.

On video simple and original way Pulling the cable into the pipe with a vacuum cleaner.

Pipe for cable laying in Earth is universal solution For many construction and engineering tasks, such as laying an electric cable in the depths, be it the Internet, network, a signaling system or any other.

This product from polyethylene avoids the air gasket of electrical networks in areas with frequent storm and gusty winds.

The cable gasket in the ground is one of the most popular wires of laying wires.

That is why the range specifically for this purpose is not limited to one or two options.

Why is this high-cost at first glance so popular?

Causes of using pipes for cable laying in Earth:

In the air method of placing the cable, any strong impact impulse can disrupt its integrity, which will not happen in the depths of the Earth.
When icing in the winter season, breakthroughs often happen.
In this case, there is protection against the vandals (it is much easier to cut off the part of the cable hanging in the air than digging it out of the ground).
Damage caused by the downtime of the plant, enterprises can be significantly higher than saving when installing.
If there is a short circuit, it will not be any ignition anyway.

What pipes are used to lay cable:

Steel (not suitable for power lines and do not protect the line in disruption of integrity).
Asbic cement (heavy, harmful to human health due to asbestos).
Polyethylene high or low pressure (durable, durable and lightweight pipes that are not exposed to no rejection or corrosion).
Propylene (from heat-resistant and plastic polymer propylene).
PVC (polyvinyl chloride).

PND pipes (low pressure polyethylene) have been greatly popular in the last few years. They are light or heavy corrugated, smooth-suited hard, halogen-free, double-wall. Each options performs its functions.

Corrugated at the expense of corrugations have increased elasticity, and when applying the reinforcing grid, inside its structure becomes heavy. From here they got their name. Double (double-wall) have in their shell not only corrugations, but also another layer - high pressure polyethylene.

A feature of this type of building materials is the fact that the magnitude of the ambient air temperature during laying of such pipes does not matter. They are also light and easy for installation, and their life is about fifty years in theory, in practice - even more.

There are several types of pipes suitable for laying cables in the ground. Among them: asbestos, PVC, PND, double. For different types of wiring, they use different from the quality of the pipes.

Use of PND pipes and their features

Why is it cheaper? The fact is that the material for the production of this product is waste from other industries with the addition of the desired synthetic additives.

Among the advantages of PND pipes are the following:

Large service life (nominally 50 years).
It does not require the use of a welding machine for connecting sections of the cable track.
Small weight.
Using no additional grounding.
Pipes are not spoiled under the influence of the environment, its factors, as well as the time factor.
Hold the temperature in the range from minus twenty-five to plus seventy degrees Celsius.
PND pipes do not emit toxic and other harmful substances, and also do not release condensate to the surface.
The polymer, which is the main component of the product under consideration, is easily beaten in any direction, so does not require additional fasteners and connecting parts. However, too much flexing the pipes should not - the cable will not pass.

PND pipes are widely used in the modern technological Internet world. With the right approach to the process and the correct gasket, you can achieve an excellent result: the repair of the object will not need a very long time or will not be needed at all.

Technical parameters, labeling and types of protective pipes

What are the PND pipe cable protect?

From mechanical damage, wandering current, chemical impact of soil and its components.

For the purpose of use, electrical and purely technical pipes of the PND are distinguished.

The first view includes additionally protected corrugated or double tubes ( a distinctive feature Corrugated products are smooth internal).

For technical purposes, simple single-layer PND products are used that do not give additional protection.

Corrugated pipes can be suitable for laying in the land of telephone, television, computer, electrical cable.

It is important that the current current to the mentioned wire is variable or permanent, but not more than 1 kV. In turn, the corrugated pipes are divided into two subspecies: with or without probe.

If the first was selected for work, it will be quickly and without problems. When buying a product without a drawn mechanism, you also have to acquire a reusable mechanism for pulling the cable.

The technical parameters of the pipes include such concepts as the thickness of the pipe, the wall thickness, color, compliance of the GOST, the presence of labeling, the number of layers. Usually for this product the following rule is performed. Than more diameter Pipes, the thicker of its wall.

The latter parameter may vary in a large range. The minimum wall thickness is two millimeters. In this case, the diameter of the pipe itself is from 16 to 50 mm. The maximum wall thickness is almost three centimeters. In this case, the diameter of the pipe is twenty to twenty five centimeters.

Wear-resistant PND pipes withstand pressure from twenty to thirty eight megapascals, and the linear expansion coefficient is one hundred forty pascal. But not for all work on the cable laying underway, such strong and protected products are needed.

Therefore, manufacturers and sales in stores exists a whole line of different pipes:

Lungs - withstand pressure up to a quarter megapascal
Medium-fashioned - up to four tenths
Average - up to six tenths
Heavy - to one megapascal

On each sleeve for laying the cable there is a marking corresponding to its technical characteristics. This conditional designations showing what parameters is something or another product.

In addition, the application of the designations on the pipes allows you to control the compliance of the stated quality level of the one that has a specific pipe.

Product classes with appropriate labeling:

"T" - heavy trumpet
"ST" - medium-heavy trumpet
OS - Middle Easy Pipe
"C" - medium pipe (by weight)
"SL" - middle-aged pipe
"L" - light tube

In addition to weight information, which is directly proportional to the fortress, also indicate its wall thickness. To protect underground a thin cable (cross-sectional area - one and a half or two square millimeters), a pipe with a radius from eight to twelve millimeters will be required.

Moreover, the number of wires can vary from one to four pieces. If the cable has a cross-section from six to sixteen square millimeters, you will need a PND tube with a diameter of from twenty to forty millimeters, respectively.

The final choice should be based on the calculation, how many stacs will be enclosed in low pressure polyethylene. For example, for three cables, each of which has a cross-sectional area equal to ten square millimeters, you need to select the same pipe as for two cables with a cross-section area of \u200b\u200btwenty-five millimeters.

What can be said about thicker wires? If the cable in the cross section contains from thirty-five to seventy square millimeters, then the pipes will be needed more. Namely: from 40 to 50 mm in diameter.

If the pipe is not corrugated, it can not bend and sold limited length: for diameter up to nine centimeters The length of the product may be a hundred or two hundred meters.

With an increase in the width of the lumen, the polyethylene sleeve is reduced - for example, twelve meters each.

Another important criterion for assessing the quality of the pipe is an indicator called SDR. It is calculated by mathematical division of the outer diameter on the wall thickness. With an increase in this special indicator, the overall strength of the pipe becomes below.

Locking technical protective sleeves is a process similar to the installation of electrical hoses. Differences are only in the appointment and marking. PND pipes of this type are used to launch underground networks that are not electrical. For example, heat pipelines, sewage.

Used for the production of similar pipes waste from other industries. For example, from the brands "PE" thirty second, sixtieth and eight-dimension, as well as a hundred. The radius of the product may vary from one centimeter to twenty five.

In addition to technical I. sewage water Such polyethylene products are used for non-pressure water supply systems, in ravery, drainage systems, for amelioration, irrigation of crops.

Installation is carried out using fittings, adapters and couplings, as they cannot bend like corrugated pipes. In some cases, when it is necessary to ensure one hundred percent sealing, apply special welding "Jack" or compression fitting.

On the quality and operating parameters of PND pipes are judged by labeling, which shows all important technical features Products.

Read more about the corrugated pipe can be viewed on the video:

How the cable is laid underground

To lay the cable in a special pipe under the ground, you need to observe a clear sequence of such actions:

Inspection of the PND products for damage. The same should be done with the cable itself.
Perform the markup of those places where the pipe should be laid.
Trenches needed for cable depth (minimum twenty five centimeters).
Putting the pipe.
Stretching the cable (it must eventually lie inside without tensions).
Falling asleep with a decade-penimetime layer of sand and a fifteen-centimeter layer of soil or land.
Putting the signal tape throughout the perimeter of the cable laying (optional).

When performing data, it is necessary to remember that when placing the power cable is better to avoid the use of adapters, couplings or use them only at extreme need. Of this simple rule It is necessary to adhere to ensure the most secure sealing.

In the locations of the construction of the construction from the Earth and the entrance to the building you need to use special fittings. As for the minimum cable cross section for styling underground, it is recommended to use not the thinnest. For example, a wire is suitable, with a size of a section of four millimeters.

The pipe for laying the cable in the ground under the road, near buildings, production facilities should take into account the entire maximum load that can be on top.

But this is not the only requirement for successful and long exploitation, as well as the operation of the cable, in it being.

It is also necessary to accurately follow the rules of laying.

Locking electrical cables, it is necessary to take care of their protection, regardless of the street, communications or in the building are mounted. The most common material used to protect communication networks is PND pipes (low-pressure polyethylene tubes), providing reliable protection from any external influences. About what pipes are paving the cable in the ground, and will be discussed in this article.

Production of PND pipe

LDPE and MDPE polyethylene are used as the feedstock for the production of corrugated pipes. Pipes that are not susceptible to burning or well-flameable, in addition to polyethylene, are in their composition the flames.

Method of production polyethylene pipes is extrusion. All work is carried out using high-tech equipment, in the automatic mode of tracking quality of finished products. Terrible control and tracking of working parameters makes it possible to optimize the costs of the source material, minimize the likelihood of marriage production and reduce the cost of finite products.

PND pipes consist of one layer, which is distinguished by a smooth surface. Such a pipe does not pass the electric current, has excellent strength characteristics and withstands the impact of most aggressive chemicals. Standard color of polyethylene pipes - black. Flexible PND pipes are well suited for mounting electrical networks in the building.

PND pipes for cable laying in the ground

Laying an electrical cable under the ground can be performed using the following types of PND pipes:

Light corrugated;
Heavy corrugated;
Halogen;
Rigid smooth;
Double-wall.

To give a corrugated tube with a large rigidity, you can use a metal wire as a reinforcing element. Pipes with two walls are distinguished by a smooth polyethylene inner shell and corrugated top layer. A similar device has an increased degree of ring rigidity that provides an additional strength design.

Smooth-beamed pipes are the optimal option for mounting an electrical cable, a seriously simplifying process of laying communications. Easy installation is also supported by a small weight of polyethylene products, which does not require complex and bulky equipment. The tube connection technology provides for the use of couplings without fubs.

Two-layer gofrots have all the advantages of polyethylene products, including the possibility of mounting at negative temperatures. Standard cable laying pipe in Earth can serve over 50 years, which is considered a very good indicator in comparison with other building materials.

Classification of PND pipes for cable laying

When laying electrical networks, standard black pipes are commonly used. The corrugated pipe for laying in the ground is great for the arrangement of various communications, the capacity of which does not exceed 1 kW - and these are telephone and television cables, computer and household electrical networks.

The cable laying can be performed in three ways:

Open;
Semitted;
Hidden.

All these ways to one degree or another are used both on the street and in the building. The corrugated pipe for cable laying in the ground has all the necessary characteristics, among which high strength, flexibility, the ability to change linear dimensions and simplicity of installation contribute very much.

Polyethylene pipes can be released with a probe (broach) and without it. Broach is a special design element that allows you to conduct a cable along the inner surface of the pipe. Pipes with the probe are very convenient and allow you to significantly reduce the time required for laying the communication line.

In addition, the broaching cable in the pipe can be performed using special devices, but it is very difficult and requires special equipment. Pipes that do not have broach are quite suitable for reusable, but the laying of the cable in it is carried out with large labor costs.

Technical characteristics of PND pipes

According to standards, the finished product should not have any damage - various influx, bloating, cracks and other defects are not allowed. In addition, the pipe should not be extinguished. The inner part of the pipes must necessarily be perfectly smooth, and the outer is to have a homogeneous structure.

Any PND pipe for cable laying must have a high degree of wear resistance. Polyethylene products are able to withstand internal pressure up to 20-38 MPa with a linear extension coefficient of 140 Pa, depending on the type of pipes.

The working pressure value for different types of pipes is as follows:

Light electrical pipes - 0.25 MPa;
Medium-germ - 0.4 MPa;
Middle PND pipes - 0.6 MPa;
Heavy pipes - 1 MPa.

Advantages of PND tubes

Among the advantages of PND pipes should not be noted and a long service life, which, under reasonable operating conditions, reaches 50 years. To considerably, this is determined by the total resistance of polyethylene products to the effects of corrosion and aggressive media, as well as the absence of condensate on the surface of the pipe. The operating temperature of plastic pipes, at which they do not lose their characteristics, ranges from -25 to +70 degrees.

Installation of pipes of small diameter is fairly simple and does not require the use of special equipment. Various connecting elements are also not required - the possibility of free bending (of course, within a reasonable limits) allows you to pretend the pipeline in almost any conditions. In addition, polymer pipes are not current conductors, so when they are installed, it does not require grounding, and non-combustible allows you to prevent combustion of the design even with a short circuit.

Low pressure polyethylene labeling

All PND pipes must be marked in accordance with the standards. Marking not only allows you to classify different types of pipes, but also makes it possible to control the quality of products - the applied designations are a guarantee of the suitability of the material to use.

Each pipe has symbols displaying a trademark or the full name of the manufacturer's company. Marking can be carried out on a national or international standard. The next element is the manufacturing material. For example, PE 8 pipe is displayed as MRS 8. Also, the pipe must necessarily have the designation of the minimum thickness of the walls, the outer diameter and the nominal pressure (bar).

A separate item may indicate the suitability of the pipe for the arrangement of the gas pipeline network or the transportation of drinking water. The last marking item is the party number and the date of manufacture of the pipe.

PND pipes are divided into six classes having the following notation:

Heavy - t;
Medium-heavy - st;
Middle-easier - OS;
Middle - C;
Middle-storey - sl;
Light - L.

Selecting PND pipes for cable laying

Select the protective material for the cable laying in the ground is competent. Perhaps the most important parameter from which you want to repel when choosing is the amount and dimensions of the wires of the communications network. There is a direct dependence that can be understood between these indicators and the sizes of the pipe, which can be considered in more detail the most popular sizes of corrugated PND pipes.

When choosing a material, you need to know exactly the sizes of pipes. The diameter of standard polymeric products may vary from 16 to 225 mm. Pipes with a small cross section (up to 90 mm) are available in bays, the length of which can be 100 or 200 m. If the diameter exceeds 90 mm, then the length of single pipe segments is 12 m.

To estimate the degree of strength of the pipe, you need to know what is equal to the SDR parameter. To calculate this parameter, it is necessary to divide the outer diameter on the wall thickness. The strength of this parameter is estimated simply: the less the result of the calculation, the greater mechanical strength has a product.

Features of laying technical pipes

You can stack technical pipes on the street, underground and in any buildings. When laying protection in the building, the pipeline should not be located open, but to be installed in concrete, brick or drywall walls.

The main nuances arising from work look as follows:

The installation of polyethylene pipes is possible at ambient temperature not lower than -30 degrees.
If the design is laid in a trench, the depth of which exceeds two meters, you need to take care of the protective concrete channel with a thickness of 80-100 cm.
With the horizontal location of the pipeline, the protection can be concreted in the foundation.
Putting the PND pipes for the cable in the ground, it is necessary to follow the tightness of all connections - this will allow you to protect the design from different contaminants in it. To connect individual parts of the pipes, compression clutches and butt welding are best suited. Using the fittings in the pipeline design, you can simplify installation and improve the reliability of the connection.
In the event that the design will work in the conditions of the possible appearance of condensate, you need to take care of the installation of an extensive tube that ensures moisture collection.

Laying electrical cables in structures

When arranging hidden wiring, it is possible to use smooth or corrugated pipes - there is not a single standard that would forbid such protection.

The installation of the PND pipe is as follows:

First you need to mark all the points through which the cable will pass;
The pipe is fixed in accordance with the selected trajectory;
The pipe is stretched by an electrical cable;
Design closes concrete screedIf the pipeline is located on the floor, or plaster when communicating on the ceiling or wall. The cable gasket in the pipe allows you to repair or update the wiring without disturbing the integrity of the surface under which the pipeline is located.

To the floor, if you wish, you can attach pipes using metal brackets, and holders with a latch are suitable for fixing the design on the wall or ceiling. In any case, when laying the cable you need to make sure that there is no tension.

When arranging communications in the room, you can use connecting elements for mounting the pipeline segments, but the best choice It will still be corrugated elements - this will avoid the sleepers of the smooth pipe, due to which the material can be deformed.

Cable Laying on Street

The need to lay cable on the street often occurs on its own land plots. Of course, we are talking, including about protecting the electrical network. Before laying a cable in PND pipes, you need to make sure there is no damage to its structure.

Laying PND pipe for cable in the ground looks like this:

First you need to place the trench of suitable dimensions and dig it;
The trench is placed selected PND to the underground cable laying;
The pipe is a cable (tension should not be);
After pulling the cable, the pipe is covered with a 10-cm layer of sand and 15-cm - soil.

So that in the future the paved cable could be found, it is worth leaving a signal tape or similar material. Locking pipes in Earth, it is advisable to refrain from their connection with the help of couplings and other connecting elements - they can cause sealing disorders. Fittings can only be used to enter the electric line in the building.

The trenchless way of laying the cable in the ground

In some situations, there is no possibility to prepare a trench for laying a protective pipeline. In this case, it is possible to pave a cable in a pipe only with the help of special equipment that allows you to implement a trenchless laying method for which the soil drilling is performed horizontally - drilling engineering technology, which is often non-alternative. Before working, in addition to the preparation of technology, it is necessary to obtain a permit for drilling and conduct a geological analysis of the soil.

Laying the cable in the protective tube is carried out according to the following algorithm:

First, the pilot well is clogged;
Well dimensions increase;
PND tube is installed in the well with an electrical cable in it.

When drilling a well, the soil puncture is carried out through which a solution that fills the well adding to it and the cooling tool during operation will be supplied to the ground. To expand the well, the trimmer is used, which is installed on the equipment instead of the previously used drilling head. Installation of PND tubes in the well is also performed using equipment.

Horizontal drilling technology has one significant disadvantage - the performance of work requires specific skills and equipment. Because of this, it is possible to implement this method only specializing in the drilling of the company's soil.

Conclusion

PND tube for cable laying in Earth allows you to protect the electrical line from possible damage provoked by external factors. Polyethylene products possess all the necessary characteristics and have affordable priceTherefore, they should be considered first.

The use of pipes for laying cable in Earth allows you to further protect the communications from external influences. The article will talk about the nuances of this process and the pipes used.

Used pipes, reasons for their popularity

One of the most popular wire laying options is the placement of them in the ground. To implement such a method, special pipes are used.

Causes of popularity:

With overhead placement, the cable may suffer from a wind gust, and the above-described method of such a shortage is deprived.
The underground wire is much more difficult to damage, there is also a protection against external weather conditions.
Even in the case of a short circuit, the wire will not be marked due to protection.

There are five types of pipes intended for launching a cable:

Polypropylene. This material is distinguished by plasticity and heat resistance. Such pipes easily give the desired form.
Steel. Such pipes are not used for laying power lines in the ground. As a rule, the steel pipe for the cable is used in the premises using corrugations.
From high and low pressure polyethylene. This type of pipes are covered with light weight, durability and high service life, it also has protection against corrosion.
Asbic cement. These are heavy pipes, they contain asbestos, which is harmful to the human body.
PVC pipe.

Low pressure polyethylene pipes are currently in the greatest demand (abbreviated PND). There is a huge number of varieties of such products: smooth-beamed hard, double-wall, corrugation and so on.

Gofrotube for laying cable in the ground is high elasticity, as well as heavy weight due to the reinforcing grid inside. In two-wall pipes, in addition to corrugations, there is a PND layer.

One of the main advantages of cable laying inside such a product is that it will be completely hidden from environmental exposure. Pipes are distinguished by durability, the manufacturer declares that they can serve up to 50 years. In fact, this term turns out to be higher.

PND Pipe Features

Features of the use of pipes from PND:

The PND pipes are very simple installation;
For laying of electrical network cables, pipes with corrugations are suitable;
If the installation is performed correctly, the pipes form a hermetic compound;
PND pipes are returned to the previous linear size. Simplify the cable broach allows the use of the probe.
The PND pipes have a high elasticity indicator (more detailed: ""). Therefore, they can be used year-round, the change in the soil temperature will not affect them.

For laying alarm or power cable optimal are two-plated corrugated pipes. Their use allows you to protect the line from any external influences.

There are two various views Pipes, in the manufacture of which was used low pressure polyethylene: products corresponding to the GOST standard, and other products from the secondary market. The second option is characterized by worse quality. It can be chosen if the budget is limited.

Benefits of low-pressure polyethylene pipes:

High service life (manufacturers declare 50 years);
For the connection of individual pipes, welding is not required;
Light design;
Over time, the product does not lose its operational characteristics;
On PND pipes, external factors do not have a negative impact;
For cable laying in such pipes, no additional grounding is required;
A wide range of operating temperatures - from -25 o C to +70 o C;
PND pipes do not provide negative impact on the environment, since they do not emit toxic waste or condensate;
Low pressure polyethylene pipes are easily deformed, it does not need to use additional fastening and connecting parts for the mains of the highway. But it is worth understanding that in the event of a strong bending of the pipes, the cable will not climb into it.

Types of protective pipes

What are PND pipes are used for? They are designed to protect the cable from various influences. In the soil contains chemical compounds that may harm it. Also, the danger of cable is mechanical damage or load and wandering current.

PND products are divided into electrotechnical and purely technical. The first category includes reinforced corrugated or double tubes. They are distinguished by an increased degree of protection. Pure technical pipes are simpler, they are single-layer, there is no additional protection. But the price of them will be lower.

Corrugated wire laying pipes are used to protect telephone lines, electricity networks, and so on. It does not matter, alternating or permanent current goes via cable. But the voltage should not exceed 1 sq. M.

In the information about the technical characteristics of the pipes, it is indicated: coloring, labeling, sizes, wall thickness, number of layers, compliance with GOST. Typically, such a pattern is valid for this type of product: the thickness of the wall directly depends on the pipe diameter. The greater the first parameter, the greater the second.

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

Classification of pipes according to limit pressure:

Light (permissible pressure - 0.25 MPa);
The middle-deep (permissible pressure - 0.4 MPa);
Average (permissible pressure - 0.6 MPa);
Heavy (permissible pressure - 1 MPa).

The cable marking corresponds to its performance. You can find it on the "sleeve". Thus designated the weight of the product.

Pipe marking:

"L" - light;
"Sl" - the middle-aided;
"C" - average;
"OS" - medium-easier;
"ST" - moderate;
"T" is heavy.

In addition to the information about the weight, which directly depends on the fortress of the product, also indicate the diameter of the pipe with a wall thickness. These are the necessary information for cable laying. For example, if you plan to run a cable under the ground with a cross section of up to 2 square meters. mm, then the pipe radius must be in the range from 8 to 12 mm.

Inside the pipe, you can make several cables simultaneously (maximum 4 pieces). If its cross section is from 6 to 8 square meters. mm, then you need to buy a pipe with a diameter in the range from 20 to 40 mm.

You need to choose the pipe with the number of wires in it. For example, if you plan to spend three cables with a cross-section area of \u200b\u200b10 square meters. mm, then a pipe is suitable for the same diameter, as for two cables with a cross section of 25 square meters. mm.

Let's go to the wires thoroughly. For cables with a cross section from 35 to 70 kV. MM The optimal diameter of the pipe will be from 40 to 50 millimeters. It should be borne in mind that with increasing the width of the lumen decreases the size of the sleeve.

Another significant characteristic of the pipe defining its quality is the SDR indicator. To calculate it, it is necessary to divide the outer diameter of the product thickness. The higher the values \u200b\u200bof this indicator, the lower the reliability of the pipe. Therefore, it is impossible to choose products with too thin wall relative to its diameter. After all, it will be faster due to low strength.

Laying of technical sleeves general principle Looks like stacking electrical sleeves. There are only appointments, as well as the corresponding marking. Technical pipes made of low-pressure polyethylene are designed for styling in the soil of non-electrical communications. For example, they can be used to conduct heat resistant or sewage.

For the manufacture of technical pipes PND applies secondary raw materials from recycling. For example, from products with labeling "PE 32", "PE 64", "PE 80" and "PE 100". The diameter of such pipes in the range from 2 to 50 centimeters.

Such pipes can be used not only for the removal of technical fluids or sewer water. They are also suitable for the implementation of drainage and landlocation systems, installation of non-pressure water supply and similar communications.

Technical pipes for cable in Earth can not be bend or deformed, unlike corrugated products. Therefore, connecting fittings are used to create turns: couplings, fittings and adapters. For absolute sealing, it is possible to welding "online" or the use of compression fittings.

Read more information about the PND pipe from marking. It will determine the specifications of the product.

Principle of laying cable underground

When laying plastic pipe For laying cable in the ground, you must follow the following steps:

First of all, it is necessary to check the PND pipes. They should be missing any damage. The same applies with the extensionable cable.
In places of laying the pipe, you must apply markup.
Now you can switch to digging the recess of the desired sizes to lay the cable.
Then running the pipe itself.
And now the cable is already stretched in the pipe. He should not stretch inside.
The entire design must be burned with a layer of sand in 10 centimeters and a layer of soil in 15 centimeters.
On top of the embankment, you can set the signal tape. This stage can be skipped. The tape will act as markup.

If the power cable is placed, then the preferably not to use adapters and couplings at all. When it is impossible, their quantity must be minimized. The fact is that adapters and clutches will disrupt the tightness of the pipeline, which is so needed for the power cable.

In those places where the pipes come out of the soil and enter the building, special fittings should be installed. How are things with a minimal cable cross section for placing underground? It is best to take not the thinnest wires. For example, a cable is well suited, whose cross section will be from 4 mm and more.

If the above-described method of laying pipes with a cable is not possible, then horizontal laying applies. It requires drilling to implement it. Among the advantage this method It is possible to allocate the lack of need for land. No need to dig a trench for communications.

For starters, engineering surveys are performed. So called work on the study of the characteristics of the soil on the ground, where construction is planned. Drilling cannot be performed until the relevant documents are received.

When you have permission in your hands, you can move to the main part. It all begins with drilling a pilot well. A special drill is used with a radiating head that easily destroys the soil. When it faces the void, the liquid is filling. It is designed to cool the bora, but also prevents the land collapse.

At the next stage, the well extension is performed. For this, a nozzle under the name of the Rimmer is put on the boring. Then you can move to tightening the pipe with the wire in the well. To do this also use drilling rigs. This is the most responsible stage of work, it is also final.

Laying cable in a pipe under the road

Some situations require cable laying under the road. This is a rather difficult way that is used in case of the impossibility of pumping the trench. A specialized organization will be able to cope with drilling, which includes the necessary equipment.

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

You need to fully follow the installation rules. In this case, the cable will be maximally protected from the effects of the external environment, and the PND pipe is not extended ahead of time.

The concept of "cottage" often implies the presence of not only the main residential building, and a few additional economic objects.

Garage, summer kitchen, gazebo, sauna - these buildings are needed in the farm and must be uninterrupted with electricity.

The subtleties of underground wiring in the country area. How to choose corrugation for cable

One of the methods of laying an electrical cable in the country area - underground. This option is solid, reliable, aesthetic (wires do not spoil appearance courtyard). However, it requires a clear compliance with technology and instructions. Mandatory point - buying corrugations for cable, special protective shell.

Of course, with special attention, you need to take the choice of a suitable for launching the cable in the land - here it is not necessary to do without consultation with the electrician. But it is equally important to choose the defense in which it (cable) will be "packed" when laying on the depth to ensure its integrity and functionality for the entire period of operation.

The main thing you need to know are underground layout requires the use of a special corrugation of the PND. "PND" - the abbreviated name of the main material of such a pipe, - low pressure polyethylene. Such a corrugation is characterized by increased strength and has a number of specific characteristics. The process of laying is another story, and below we will share the extracted from the electrician tips for choosing.

The main differences of corrugations for underground cable laying from ordinary

Two-way design: the outer sheath is corrugated, which guarantees high strength of the pipes, and the inner wall is smooth (it provides a lightweight cable broach over the entire length).

Resistance to shock loads and vibration and at the same time plasticity in operation. This allows you to use the PND corrugation for both the cable laying in open areas and in the ground or concrete screed.

A wide range of operating temperatures that corrugated withstands without destructive consequences (from -40 to + 90 ° C).

The bonded corrugation in the bays is equipped with a special stretch (probe) - for the convenience of the cable to make along long sections. The bays are found 20, 50 and 100 meters long (a greater layout for wiring on private facilities is rarely required).

Visually corrugation, suitable for underground use, also differs from the usual gray PVC pipe red or orange color (less likely, depending on the manufacturer, it is black).

The diameter of the PND corrugation depends on the characteristics of the cable selected for bookmark to the ground. For cottage underground wiring, the pipe with an external Ø40 mm is most often choosing with an internal Ø32 mm (it is minimal possible). For example, .

Why? The fact is that for underground installation in the courtyards of private cottages, electricians are often recommended for 3x2.5 with external Ø10.5 mm (cross sections of such a cable for the domestic power supply of most economic buildings). Judge yourself: the cable of such a girth with a margin is placed in a two-layer tube with internal Ø32 mm. The maximum possible values \u200b\u200bof the corrugation reached Ø200 mm, but are used in purely industrial purposes.

When buying a corrugation of 6 meters long in length (by the way, not all specialized stores Sell \u200b\u200bsuch pieces, specify this moment immediately) Be prepared for the fact that the broach is missing in them. And this is justified. On a small length, stretch the cable is not difficult and without broach.

Try to choose even for laying in the land of the corrugation, not supporting burning.

The strength of the compression of the selected pipe must be high - focus on the rate of at least 6-8 kPa.

But the level of resistance to ultraviolet here can be neglected here, because under the ground the issue of protection from the sun is not relevant.

Special corrugation is important

Imagine which titanic physical, temporary and material costs will entail the replacement of the failed cable, burned in the ground cottage plot At a depth of 70-80 cm. This is not to dig potatoes! Buying a special protective corrugation is not unnecessary (notice, one-time) costs, but the necessary insurance in order to use the country's good benefits, it was comfortable and easily a few decades.

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