What types of metal pipes for electrical wiring are there - characteristics and selection rules

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Corrugated pipe assembly diagrams

JSC KTC Metallokonstruktsiya produces metal corrugated sheets (LMG) and prefabricated metal corrugated structures made from them (SMGC and SMGT).

The practice of using LMG corrugated steel sheets in construction—lighter and stronger than conventional ones—proves the promise of using LMGK.

Materials for the manufacture of tubes for electrical wiring

The choice of material from which the channel is made depends on the type and characteristics of the room where the wiring is planned.

Pipes can be made from:

• plastic;
• copper;
• brass;
• become.

In the manufacture of plastic products, polyvinyl chloride (PVC), high-pressure (HP) and low-pressure (LP) polyethylene (D) are used. Products made from polyvinyl chloride are in high demand among consumers because they have an affordable price and are characterized by good strength and resistance to high temperatures. The most common PVC pipes have a diameter of 16 to 60 millimeters.

Plastic products have a smooth inner surface, and this feature makes it easier to carry out work related to replacing conductors. They are also lightweight and resistant to corrosion. In addition, channels made of polyethylene and polyvinyl chloride are dielectrics and therefore can be considered an additional insulating circuit.

Steel pipe for electrical wiring has a significant mass, but at the same time it is a high-strength product. This product is recommended for use when laying channels in wooden buildings. Since steel is a good conductor, such wiring must be grounded to ensure safety.

Brass or copper thin-walled tubes are suitable for installation on wall surfaces and for concealed wiring. Such products bend easily and do not require decorative design.

Pipe head design

For pipes with a hole diameter of 1, 1.5 and 2 meters, cap parts with a vertically cut end are used. For pipes with a hole diameter from 2.5 to 8 meters inclusive, cap parts with an end cut off along the embankment slope are used.

EDGE CORNERS

The bordering corners serve to impart rigidity to the ends of the pipe. Bordering corners are installed along the entire circumference and only on corrugated pipes 130x32.5 mm with a diameter of 1 to 2 meters. Bordering corners are not installed on the end parts of 150x50 corrugated pipes, since pipes with 150x50 corrugation have sufficient rigidity.

ANTI-FILTRATION SCREENS

Anti-filtration screens serve to prevent groundwater from flowing under the pipe body and soil erosion, which can lead to the destruction of the road and pipe. Since the screens do not carry any force loads, they are made from corrugated sheets with a thickness of 2.5 and 3 mm with a corrugation of 130x32.5 mm without giving the sheets a radius. Assembly is carried out using M16 spherical bolts.

The anti-filtration screen is attached to the pipe using the corners of the anti-filtration screen.

Anti-filtration screens are very diverse in their design. Each customer has their own screen dimensions in terms of width and height, sheet thickness, etc. - depending on the project. Therefore, each anti-filtration screen must be considered individually, which leads to individual labeling.

Corrugated 381x142 mm

Prefabricated metal corrugated structures of various modifications are made from corrugated sheets with a corrugation of 381x142 mm:

Large polycentric corrugated

Box-shaped

Radius arched

Radius closed

Average polycentric

Rules for installation work

Before you begin laying a cable route using a thin-walled metal pipe for electrical wiring, you need to familiarize yourself with some important rules:

1. The ends of each tube segment should first be cleaned of burrs and countersinked.
2. The maximum bending angle of a steel channel is 90 degrees.
3. You should adhere to the limitation on the length of the sections, which for a straight tube is no more than 10 meters and in the presence of 2 bends - up to 5 meters.
4. When bending is performed, it is necessary to carefully monitor the integrity of the cross-section of the pipe product.
5. The cable duct is installed as part of a potential equalization system (abbreviated EUP).

If it is impossible to fulfill the conditions regarding the choice of length in accordance with the current rules, install the pull-out box, without additional joints.

SUP assumes that all conductive parts are connected into a single system in such a way that the potential difference between them is minimized or completely eliminated.

To do this, it must include:

• grounding device;
• the main grounding bus, which is mounted in the electricity metering panel or in the input panel;
• all metal elements of the created structure.

Provided that all of the above rules are followed, installation work and replacement of electrical wiring can be significantly simplified.

QUALITY AND SPEED OF PRODUCTION OF CORRUPTED PIPE

The high quality of the prefabricated LMG, SMGT and SMGK metal structures produced by KTC is achieved through the use of modern equipment, professional personnel, and strict quality control.

A wide network of branches and warehouses of Integrated Technical in Ulyanovsk, Moscow, St. Petersburg, Rostov-on-Don, Krasnodar, Crimea, Voronezh, Yekaterinburg, Surgut, Novosibirsk, Irkutsk, Khabarovsk, Yakutsk allows you to quickly meet the needs of the company’s partners and deliver corrugated structures to short time.

Laying copper and brass channels

Tubes for electrical wiring made of copper are not popular among consumers due to their high price.

Such channels have the following features:

• Compared to steel products, copper and brass are not subject to active corrosion processes;
• they can be quickly installed with your own hands, since there is a wide selection of fittings on sale;
• uncomplicated work is due to the excellent bending properties of a thin-walled pipe for electrical wiring (pro

DIRECTIONS OF USE OF PREFABRICATED METAL CORRUGATED STRUCTURES

Currently, the following areas of use of prefabricated metal corrugated structures can be distinguished:

• — construction of culverts
• — construction of protective structures
• — construction of engineering structures
• — construction of industrial and transport facilities.

In Russia, MGCs are most widespread in the construction of small artificial structures (ISSS) in transport construction.

Pipes or arches are assembled from steel sheets bent along a radius and filled with soil. The metal shell in the form of a corrugated sheet works together with the soil, which takes part of the load (compressive forces).

The production of metal corrugated structures (MCS) is carried out on 3 production lines equipped with modern foreign-made equipment.

Advantages of metal tubes for channels

The main advantages of metal pipes for electrical wiring are:

• resistance to different temperature conditions;
• dimensional stability;
• wear resistance;
• UV resistance;
• practicality;
• reliability;
• variety of solutions.

Metal tubes for electrical wiring can provide high-quality protection of channels from humidity, rodents, temperature changes and mechanical stress. They are used for a long time, especially if they have a protective layer. These products do not require special maintenance.

Thanks to the wide variety of diameters, parameters and other characteristics of pipes for electrical wiring made of metals, it is possible to easily select the desired option for cable laying channels that matches the personal preferences of consumers.

Metal tubes, subject to operating rules, do not change their size and shape. They are used for laying internal and external (hidden and open) wiring in both heated and unheated rooms. There is also a special pipe for laying cables underground, which is designed specifically for this.

How does a metal mill work?

The corrugated metal hose works as a containment barrier with high pressure on the hose containing the wiring. This is especially true for installing cables in the soil. The tube links act as stiffening ribs here.

If we take smooth-walled and corrugated pipes with equal nominal diameters for comparison, the area of ​​the second will be significantly larger than the first. Here you can trace the principle of operation of the protective channel using the formula from the school course of general physics:

• P=F/S,

where the values ​​are interpreted as follows:

• P – pressure on the pipe;
• F is the force that acts on the surface perpendicular to its plane;
• S is the area of ​​the desired surface.

Having analyzed the formula, it becomes clear: the larger the total surface area that is subjected to mechanical action (external pressure), the smaller it is for each cm2 of the sleeve.

Application of metal pipe products

When metal pipes are used for electrical wiring, there may be difficulties associated with pulling the cable through them. This can be solved in several ways. The simplest of them is to insert a steel wire into the channel, attach a cable to its end and then pull it inside.

If the pipe is long, then you can place a ball in it, to which a strong ribbon or thread is tied. To make it easier to move, talc is used. A steel wire is attached to the end of the tape and the air compressor pipe is placed in the hole, after which the device is turned on. The ball moves under pressure along the channel and draws the tape or thread along with it. To cut the product, use a grinder or a hacksaw.

To lay electrical wiring to sockets and switches, choose products with a diameter of 20 millimeters, for lighting fixtures – 16 millimeters, 25 millimeters for connecting distribution or switchboards and boxes, and for interfloor connections – 40 millimeters. The length of the channels, as a rule, ranges from 3 to 5 meters.

When the room is too humid and there is a high probability of the presence of chemical compounds, then it is advisable to use thin-walled tubes with a diameter of approximately 20 millimeters, connecting them together with couplings without threads.

UNIVERSALITY OF PREFABRICATED METAL CORRUPTED STRUCTURES

The versatility of corrugated structures allows them to be used not only for the construction of culverts on roads and railways, but also for the construction of overpasses, livestock runs, pedestrian and transport tunnels, and avalanche protection galleries.

In cities and industrial sites, corrugated pipes are used for the construction of drainages, storm sewers, the creation of communication channels, landscaping, protecting objects from flooding, regulating water flow, and as bank protection and protective structures.

Important nuances of grounding

Protective grounding performs a safety function in the event of human contact with electric current.

Its impact is manifested as follows:

• at 0.6-1.5 thousand µA the effect of electricity on the human body is felt;
• at 2-4 thousand μA, fingers tremble;
• at 5-7 thousand μA, the hands cramp;
• at 10-15 thousand µA without outside help it is almost impossible to release the hand with the conductor;
• at 20-25 thousand μA, severe pain appears, breathing is difficult, and it is impossible to take your hands off the wire;
• at 50-80 thousand μA, paralysis of the respiratory system occurs, and disruptions in the functioning of the heart are observed.

Currently, when performing electrical wiring, it is imperative to use a device designed for protective shutdown. It is triggered almost instantly in the event of an unauthorized current leak. There are several types of grounding systems - TT; IT; TN-S; TN-C;TN-CS.

MANUFACTURE OF NON-TYPICAL PREFABRICATED CORRUPTED STRUCTURES

To calculate structures not provided for by standard designs and KTC Metallokonstruktsiya’s own technical specifications, force calculations are carried out by the designers of the enterprise’s technical department based on the following parameters:

• 1 - Height of the embankment.
• 2 - Geology under the pipe.
• 3 - Hydraulic and geological surveys.
• 4 - Construction of the earth. canvases.
• 5 — Road pavement design.
• 6 — Dynamic loads on the road or road category.
• 7 - Pipe location.

Electrical wiring using corrugated products

With the advent of thin-walled corrugated pipes, significant changes have occurred in the installation work of laying electrical cables. Metal hoses are used when installing utility lines, for example, computer and telephone lines, both indoors and outdoors.

Corrugated pipe products are suitable for power supply to the entire building (more: “How is corrugated pipe used for electrical wiring, characteristics and installation rules”). Such a cable channel is used when building new houses and when repairing or replacing faulty or outdated electrical wiring.

Installation of this type of structure does not require the involvement of professionals or the use of particularly complex equipment. Laying a sealed metal hose made of corrugated thin-walled stainless steel pipe will take just a few minutes. Such a reliable cable channel can last a long time.

Materials and brands

For the production of protective channels, stainless or galvanized steel is often used. The first option is more durable (brand MRN). Stainless steel pipes are characterized by increased rigidity and tightness.

Another brand of products is MGPng. This corrugated steel pipe is produced using a special method of winding links, using a sealing thread and thickened insulation. The durable tube is characterized by increased flexibility.

MRPIng brand - products with a top polymer coating-braid.

If you need reliable protection of the cable from water and oil products, it is better to give preference to the latter option.

Types of metal corrugation

It is customary to use several types of classification of metal corrugation. By strength class:

• lightweight – characterized by relatively low mechanical strength, therefore suitable for installing cables externally, above suspended ceilings and light plasterboard structures;
• heavy - high-strength products that allow them to be laid in concrete walls, in the ground, or covered with a thick layer of plaster;
• extra-heavy - products designed for increased mechanical loads, as well as for installation in critical areas with high fire safety requirements (in public places, hospitals, educational institutions).

According to the degree of resistance to mechanical stress:

• very light – able to withstand loads up to 125N/cm2;
• lightweight – withstands pressure of 320 N/cm2;
• medium – resists pressure up to 750 N/cm2;
• high – can withstand up to 1250 N/cm2;
• very high – withstands pressure up to 4000 N/cm2.

According to the type of cross-section, corrugations are divided into round, square, pear-shaped, arched, and elliptical. According to the flexibility class, corrugated pipe is divided into rigid, flexible, especially flexible, and pipe with memory effect.

Specifications

The products in question are represented by a whole line of pipes used to provide protection for electrical wires, various equipment, vehicle systems, and the like.

The most characteristic properties of the products are the following:

• significant protection against electromagnetic radiation;
• resistance to fuel and lubricants;
• resistance to sunlight;
• resistance to strong physical impacts;
• wear resistance;
• significant flexibility of the material;
• non-flammability.

The products in question make it possible to create high-quality and hermetically insulated pipelines for electrical wiring. Such systems will be reliably protected from moisture or dust.

Thanks to the huge range of these products, it is possible to equip a system of any complexity that will best meet the necessary requirements.
Including at enterprises in the chemical and food industries. According to consumer reviews, the reviewed products are characterized by:

• the presence of additional elements that simplify installation;
• high tensile strength;
• ease of fastening and sealing;
• ease of design;
• availability of stainless steel products in the range;
• corrosion resistance;
• absence of serious defects and burrs.

Most consumers consider the products reviewed to be reliable and affordable. Products can be used to solve a variety of problems.

Peculiarities

• Wide range of cross-section options. Thanks to this feature, it is possible to create optimal structures for each specific case, be it a railway crossing and screening of groundwater or drainage of a water channel;
• Efficiency of installation. Due to the simplicity of the design and the relatively low weight of the elements, installation is carried out in the shortest possible time;
• The possibility of dual-use of the finished pipe; in addition to directly laying a road or railway track, it is possible to lay a power cable in a niche.
• Seismic resistance. The prefabricated type of the product and the thin wall guarantee resistance to the negative effects of surrounding shocks and man-made vibrations on the entire structure as a whole:
• Steel sheet material: steel 09G2D and 15SP, wall thickness - 2.5-7 mm.

Characteristics and types of products

To purchase the product in question, you need to take into account all the available characteristics.

Products are:

1. Straight (hard).
2. Corrugated (flexible).

The key properties of the steel channels under consideration are the following indicators:

• bending capabilities;
• masses;
• length;
• density;
• diameter

The main advantages of this product are good reliability, long service life, resistance to fire, physical and other influences.

However, the structures require constant maintenance. Moreover, even their systematic painting will not provide one hundred percent protection against corrosive processes.