Asbestos pipes or, as they are also called, asbestos-cement, have always been considered a reliable and, most importantly, economical product, widely used in rural areas, in holiday villages for chimney pipes. In addition, products made from this material are widely used in construction: for example, sewer communications and the most famous - slate. But it’s no secret that slate bursts during a fire, however, this does not stop craftsmen from using asbestos pipes for chimneys. Meanwhile, this aspect is regulated by a number of regulatory documents.

Rules about fire safety It is strictly forbidden to use such material for construction. While building regulations allow the use of asbestos, provided that the temperature of the incoming gases is no more than 300 degrees Celsius. At the same time, when passing through attic space, asbestos pipes must be insulated to prevent condensation.

And although in the technical characteristics of asbestos-cement products, manufacturers indicate the possibility of their use for ventilation openings, chimneys and gas ducts, air ducts, the use of this material, in the presence of a furnace, can easily lead to very disastrous results. Please note that any attempt to make a chimney from this material on a coal stove will lead to a fire hazard, in simple terms, to a fire.

When used, it reveals all the disadvantages of this material, or more precisely, their unsuitability for use where there is a possibility of very high temperatures.

Firstly, the use of asbestos-cement material greatly reduces draft, since there is not enough heat capacity to support it, condensate is absorbed, and only vertical installation of the gas outlet is possible.

Secondly, there is no possibility to build special hatches for inspection and cleaning of soot from the chimney, which, you see, is important when using the stove for a long time. During the design, it was calculated that asbestos pipes would be used for low-power devices - geysers And gas heating with low temperature conditions.

To summarize the above, we can conclude: the use of this material is not intended for smoke exhaust systems stove heating, and sooner or later will lead to. Alternatively, it could be a burst pipe, and, as a result, exit through the resulting crack. Adjacent flammable material may ignite.

Today the construction industry can offer consumers enough safe materials, which allow residents of private houses not to play “Russian roulette”, but instead to create absolutely safe and regulated conditions for using heating systems.

Therefore, before you buy asbestos pipes and use them for chimneys, think 100 times whether it is worth doing this.

Asbestos-cement pipes made from a mixture of asbestos-cement fiber and Portland cement have the following advantages: low weight and low thermal conductivity.

Our information: Asbestos cement- this is fiber-reinforced concrete, that is, concrete reinforced with fiber. The asbestos obtained from the mining enterprise is mechanically crushed and fluffed until the fibers are separated, after which it is mixed in an amount of 15% with 85% of cement and water is added. This pulp is poured onto a mesh drum and the pressed film, 0.2 mm thick and the width of the future pipe, is wound on a rolling pin, achieving the required wall thickness, and therefore the strength of the pipe. During the manufacturing process of a pipe, asbestos fibers are oriented mainly tangentially, which ensures high strength when the pipe is loaded with internal pressure. Asbestos-cement is a good dielectric, therefore asbestos-cement pipelines, and even divided by rubber rings into four-five-meter electrically insulated sections, are not subject to electrochemical corrosion under the influence of stray currents and do not require cathodic protection or even waterproofing. Therefore, they do not have an equivalent replacement for pipelines in industrial zones, cities with electric transport and railway stations, where all highways are stretched along the tracks. In these conditions steel pipes They last only two years.

Asbestos-cement (asbestos-cement) pipes are easy to machine. Even with long-term use, asbestos-cement pipes retain a smooth internal surface, and they are also good dielectrics.
Like any pipes, asbestos cement pipes also have disadvantages. These include fragility, so special care should be taken when installing them. Cracks may appear in asbestos-cement pipes during impacts and transportation. Accordingly, when choosing asbestos-cement pipes Special attention need to be turned to the ends. Material delamination and breakage are unacceptable.
The outer surface of asbestos-cement pipes is susceptible to corrosion, and this fact must be taken into account when arranging anti-corrosion protection.
Non-pressure asbestos-cement pipes (pressure grades VT6, VT12 and VTE are also used in industry) are produced with a diameter of 100 mm to 500 mm and a length of up to 5 meters. Such pipes are connected using couplings. It is allowed to use both straight cylindrical couplings made of the same material and cast iron.
Double-collar asbestos-cement collars must have rubber sealing rings. To connect pipes in sewer pipelines, it is preferable to use cylindrical asbestos-cement couplings with threads.
It is recommended to lay asbestos-cement pipes in soil that prevents subsidence in order to prevent bending of the pipeline, as a result of which its normal operation will be disrupted.
Non-pressure asbestos-cement pipes used when laying non-pressure internal and external pipelines transporting rubble and atmospheric wastewater; during construction gravity pipes extensive hydraulic structures and drainage collectors of drainage systems; when laying underground cables, communication line cables, when installing columnar foundations for light low-rise buildings, as well as in the form of support posts for fences and fences.
Pressure asbestos-cement pipes used for pressure water supply, reclamation and irrigation systems, ventilation, as casing pipes wells, as well as during the construction of heating networks. Using an asbestos-cement pipe, you can make garage floors, as well as gutters, feeders, and trays.

Thanks to technical progress Products made from new materials, often polymers, are constantly appearing on the pipe market. However, previously popular asbestos cement is still in demand in private construction, thanks to its unique properties, which cannot be reproduced in metal or polymer pipes. Of course, the production technology has changed somewhat, however, the characteristics of the A/C pipes remain the same.

Asbestos cement is a material consisting of a mixture of asbestos (15%) and Portland cement (85%). Asbestos is a natural mineral that forms a kind of frame (reinforcement) for a cement product. Thus, the strength of the a/c pipe increases and strengthens the rather fragile material, which is pure cement.

During the manufacturing process, the first step is to grind asbestos, from which reinforcing fibers are formed. Then the resulting fibers (15%) are mixed with cement (85%) and diluted with a regulated amount of water.

The resulting mixture is placed in a centrifuge, which corresponds to the diameter of the future pipe. During the rotation process, asbestos cement is distributed along the walls of the centrifuge, forming, in fact, a pipe. Next, the product is moved to the steaming chamber, where, under the influence of high temperatures dries and acquires its final characteristics.

Important! Asbestos dust and cement suspension negatively affect the human respiratory system, so all work with this material must be carried out in protective respirators.

Scope of application of a/c pipes

Asbestos-cement pipes are used in various fields:

• for laying sewerage,
• ensuring technical water supply,
• installation of drainage and stormwater systems,
• as casing pipes for water wells,
• for creating chimneys,
• for the formation of columnar foundations.

Also, asbestos-cement pipes are used as a protective channel for laying electrical networks, telephone and Internet cables, and so on.

Note! It is known that asbestos is a carcinogen, however, such an effect of the mineral is possible only when asbestos dust enters the respiratory system. When the a/c pipes come into contact with the transported media, no harmful substances are released, so there is no risk to health. However, asbestos pipes are not traditionally used to supply drinking water.

Features and technical characteristics of a/c pipes

Asbestos-cement pipes are usually used for laying straight pipelines, since the material is quite fragile and the use of a/c tees and corners is irrational.

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Asbestos-cement pipe. Scope of its modifications

Asbestos-cement pipes are especially popular in the construction industry.

Low thermal conductivity, high strength, long service life and reasonable price allow them to be an ideal material for laying pipelines for various purposes.

Asbestos-cement pipes are distinguished by excellent resistance to corrosion, rotting, fouling, low thermal conductivity (and therefore independence from temperature factors), durability and long service life.

Pipes are either pressure or non-pressure.

IN technological process Only three components are used for their manufacture: 15% asbestos, 85% cement and water. Asbestos is a fine-fibered silicate material that, under certain conditions, breaks down into thin, plastic fibers. Thanks to the introduction of this component into the composition, the pipes acquire their characteristic properties. As for the next component - cement, in most cases, Portland cement M500 and higher is used in production.

Scope of application of asbestos-cement pipes

Non-pressure asbestos pipe

The non-pressure type of asbestos-cement pipes is produced in accordance with the established quality standard and has the following characteristics:

1. The length of the pipe varies from 2950 cm to 5 m.
2. The internal diameter size is 50... 500 mm.
3. The wall thickness is 9…43.5 mm.

Used for laying external pipelines gravity sewer, where it is not possible to build a pressure sewage system. IN in this case the costs of constructing such a sewer system will be significantly lower. A good option for shallow-depth inspection wells would be to use cut asbestos-cement rings. Installing a garbage chute and laying a sewage system from this material does not pollute environment and soil, as it is resistant to microorganisms. If it is necessary to disconnect the pipeline and possible stagnation of wastewater for a long period, the danger of soil contamination through asbestos-cement pipes is eliminated.

Another option for using a free-flow type is a shaft or box for laying telephone communications and electrical cables, since they are poor conductors of electricity. Having high electrical resistance, such pipes are not afraid of electrochemical corrosion that occurs due to the influence of stray currents.

Polyethylene couplings in non-pressure pipelines connect pipes simply and reliably.

Some types and couplings intended for the construction of heating mains for populated areas and agricultural complexes can be laid without channels and even in non-through or semi-through channels. They are the most economical option for transporting heat, since due to their low thermal conductivity there are minimal heat losses. And as thermal insulation, the heating pipe is backfilled with accessible and inexpensive hydrophobized gravel with an additional covering film of polymer material.

It has proven itself well for heating, plumbing and drinking systems, which is also suitable for ventilation and chimneys. In the construction of storm sewers, wide-diameter pipes can be used to construct a drainage collector, and smaller-sized products can be used as drainage drains through crossings and roads.

Asbestos pressure pipe

The pressure type is a straight pipe, having a strictly cylindrical shape or a bell-shaped type. Manufactured in the following standard sizes:

1. Length 2950…3950 mm.
2. The wall thickness is 7…18 mm.
3. The internal diameter size is 50…600 mm.
4. Working pressure 0.3…1.2 MPa.

L - length, D - outer diameter, d - inner diameter, S - wall thickness, I - nominal diameter.

The manufacturing technology of this modification may consist of several stages, which necessarily involve keeping the pipes in steaming chambers to enhance their strength. At the end of this procedure, the strength of the core increases to 70...75% of the initial stage.

Pressure pumps are characterized by durability and low hydraulic resistance characteristic of this type. They are used for laying gas pipelines, pressure water pipelines, pressure reclamation and irrigation systems. It is also possible to use it for the construction of wells and wells, for durable feeding troughs for livestock, as well as as ceilings for outbuildings. They are widely used in the construction of pressure sewers, sludge pipelines and siphons.

When connecting pipes to each other, threads and welding are not used, but only heat-resistant rubber seals and couplings of the TM and CAM types. Ensuring absolute tightness and at the same time elasticity of connections occurs due to the self-sealing effect of the coupling under water pressure in the pipeline. Therefore, the advantages of such pipelines include the absence of weak areas in the system - welded joints.

Benefits of use

Asbestos-cement pipes have a number of advantages over other types of pipes. They are easy to install, have great reliability and high resistance to aggressive environments. In addition, the service life is significantly longer than that of metal analogues.

Connection of two pressure pipes: 1,2 - asbestos pressure pipe; 3 - asbestos pressure coupling; 4 — rubber ring type CAM.

So, metal pipes, having low corrosion resistance, require thorough repairs after 5-10 years. Due to corrosion, a narrowing of the internal diameter occurs, which is the main reason low pressure water and low heat rate. Annual pipe blowing does not solve the problems, since the rust on the walls does not go away and again leads to a decrease in bandwidth systems.

The use of asbestos modification, on the contrary, only becomes stronger over the years. Since asbestos in an aquatic environment does not corrode and is compacted due to the hydration of Portland cement. In addition, when a water flow passes, the surface of the pipes is not prone to overgrowing.

Main advantages:

• no waterproofing required;
• during transportation cold water no condensation;
• high resistance to aggressive soils and environments;
• not electrically conductive;
• fireproof;
• frost-resistant;
• the maximum operating temperature reaches 160º C, the permissible operating pressure can reach up to 1.2 MPa;
• service life 30...35 years.

However, there is an opinion that asbestos-cement pipes are harmful when transporting drinking water and are only suitable for sewerage or other technical needs. The results of numerous studies have not been able to give an exact answer, since the presence of asbestos fibers is already present in the water before it enters the pipe. And it is difficult to cause harm to the body with the amount that is there. And it can only be compared with the impact on a person of exhaust fumes or passive smoking.

The latest data from scientific research, which was carried out in leading toxicological laboratories in Germany, Switzerland and the USA, have confirmed that asbestos and its component - chrysotile - are the safest substances among this type of minerals. Even if they enter the body, they are removed from it quite easily and quickly, without having any harmful influence on human health.

Asbestos-cement pipes have found their application in many areas: the construction of residential buildings and industrial structures, as well as the construction of communications. The popularity of this material is due to the fact that the product is quite durable. Asbestos-cement pipes are made from a mixture of Portland cement and asbestos admixtures. Manufactured pipelines differ in parameters such as diameter, length and other characteristics.

Asbestos cement pipe: what is it?

Asbestos pipes are made from two main components, which are Portland cement and asbestos fiber. Water is used to obtain a uniform consistency. The use of these materials makes it possible to obtain a material that is light in weight and has a low thermal conductivity. Asbestos cement is cement mortar, which is reinforced with asbestos fiber. Asbestos undergoes a grinding process to a powdery consistency, after which it is separated into fibers. It is these fibers that are the connecting link in the concrete mixture.

Asbestos pipes gain strength by reinforcing concrete with asbestos fiber. This allows you to increase strength by 40% compared to conventional concrete devices.

A significant advantage of asbestos is its low thermal conductivity. It is due to their low thermal conductivity that asbestos pipes are used for the construction of sewer pipelines with high freezing rates. A significant advantage of asbestos pipes is the absence of electrocorrosion properties. If the service life of metal pipelines, in which the phenomenon of stray currents is observed, is reduced to 4-5 years, then asbestos pipes, with such a negative influence, can last tens of times longer.

When choosing asbestos pipes, it is important to take into account such parameters as the diameter and length of the products. The products under consideration are of two types: pressure or non-pressure. Below is a table with technical parameters for pressure and non-pressure asbestos pipes.

What are the products in question?

In the Russian Federation, asbestos-cement pipes with a length of 3.9 to 5 meters are manufactured. Dimensions asbestos-cement products the following:

• 100 mm;
• 150 mm;
• 200 mm;
• 250-500 mm.

The diameter of the pipes is an important parameter, therefore, depending on its size, pipes are used for various purposes. The strength of the products under consideration is influenced by such an important parameter as the thickness of the pipe walls. To connect asbestos-cement materials into the main line, special connectors made of a similar material or PVC are used.

Asbestos is a non-toxic substance that does not emit toxins or radiation. The only major danger is asbestos dust, which is formed when sawing pipes.

To avoid dust entering the body, work must be performed exclusively in respirators or masks.

Types of pipelines

Asbestos-cement types of pipes are used where it is impossible to use metal. Metal is not used where available high humidity, therefore non-pressure options are taken into account.

The considered version of the products has a bending strength of 30 MPa. The compressive strength is equal to 90 MPa. These are quite significant figures, especially considering that the material has a low density.

Asbestos pipes can withstand 60 defrost cycles, which allows us to judge long term services.

The material in question comes in two types: non-pressure and pressure, as discussed above. Let's look at the difference between an asbestos-cement non-pressure pipe and a pressure pipe.

1. Non-pressure types of asbestos-cement pipes are used exclusively where there is no pressure. These application systems include: chimney, ventilation, sewerage. Non-pressure or gravity-flow products are used in construction, from which foundations and fences are constructed. This type of pipeline is used to construct underground channels for laying communications.
2. Asbestos-cement options for pressure pipes are used where materials under pressure are transported through products. The medium of these materials can be presented not only in the form of liquid, but also gas. Pressure versions of the product are used for installation of water supply systems, gas supply and irrigation systems.

The differences between pressure and non-pressure pipes lie in their sizes. These dimensions are: wall thickness and pipeline diameters. In a free-flow pipeline, the wall thickness ranges from 7 to 18 mm. In pressure products, the wall thickness ranges from 9 to 43.5 mm. The internal diameter of the first option reaches values ​​from 50 to 500 mm, and of the second type of pipes up to 600 mm. Pressure products can withstand pressure from 3 to 12 atmospheres.

To combine asbestos-cement products of pressure and non-pressure types, they are used different kinds couplings For non-pressure products, ordinary asbestos rings are used, and for pressure products, rings with rubber seals are used.

Advantages

In comparison with other pipeline options, the products in question have a number of various advantages. These products are easy to install and have high reliability and strength. They are highly resistant to both aggressive environments and moisture. If we compare products with metal counterparts, the latter option has a much shorter service life.

Metal products require replacement or repair after 5-10 years. Moreover, metal pipes are susceptible negative impact not only from the outside, but also from the inside. Corrosion causes a narrowing of the internal diameter, which results in a decrease in pressure. Even when carrying out repairs that involve purging metal devices, the problem cannot be solved. This is explained by the fact that rust does not disappear on the walls and continues to destroy the material.

If water is supplied through asbestos pipes, the material only gets stronger over time. This is explained by the compaction of the walls due to the hydration of the cement mixture.

Some of the main advantages of asbestos-cement products include the following factors:

1. The material does not require waterproofing.
2. Resistance to temperature fluctuations.
3. There is no electrical conductivity.
4. High resistance to aggressive environments and moisture.
5. There is no condensation when cold water is supplied through pipes.
6. Fire safety.
7. Possibility of transporting liquid through pipes with a maximum pressure of up to 12 atmospheres.
8. The average service life is 30-35 years.

Studies that were carried out in Germany, Switzerland and the USA confirmed the fact that asbestos is a safe substance among its analogues. Once it enters the body, rapid elimination occurs.

Flaws

Like any material, asbestos-cement pipes have some disadvantages. It is important to note them in order to determine the need to use them for certain purposes. The main disadvantage of the materials under consideration is fragility. During transportation or installation, any mechanical impact can lead to damage to the integrity of the product.

Asbestos-cement pipes cannot withstand heavy weight, which leads to damage to sewer lines and pipelines. When installing chimneys made of asbestos, there is a violation of the integrity of the products, and when exposed to high temperatures, such materials can explode. The products also do not have sufficient heat capacity, so they are not able to maintain the necessary traction. Soot settles on the inner walls of the pipes, which over time helps to reduce the diameter, and therefore the throughput and traction.

Production Features

The manufacturing process of the products in question involves performing the following manipulations in production:

1. Initially, asbestos must be crushed.
2. 85% cement and water are added to 15% asbestos.
3. The prepared mixture is poured into a special drum in the form of a mesh, in which the solution takes the shape of a pipe.
4. After squeezing, a film is formed, the thickness of which does not exceed 0.2 mm. The width of this film is equal to the future length of the product.
5. The film is wound onto the drum, resulting in the formation of a product.

The result is a pipe of a certain size and appropriate diameter, which is ready for use.

Installation features

Pipe laying is carried out according to certain requirements. These requirements include the following factors:

1. Pipes with an internal diameter exceeding 150 mm require additional processing. It is required in order to obtain the appropriate dimensions and roughness.
2. The products are connected using special couplings. These couplings are equipped with grooves as well as corresponding rubber sealing rings. For a certain pipe size, appropriate couplings are used. This type of connection design allows for a high-quality fit of the pipe to the coupling, which is important in the presence of internal pressure in the pipeline.
3. A radial gap is left at the junction of the products. Such a gap is required in order to ensure deflection of the pipeline when the seal fails.
4. Installation of pipes with diameters of more than 150 mm is carried out directly with indentations. This is done for the purpose of eliminating the need to install additional linear compensators.

When asbestos pipes are heated to temperatures above 100 degrees, the walls increase (asbestos modification) by 0.4 mm. To avoid failure of the rubber seal, it is deformed by the end parts by 0.2 mm.

When installing asbestos-cement pipes, the need for welding work is eliminated. This makes the job easier and also speeds up the installation process.

Requirements for the production of asbestos-cement pipes

There are some requirements for the production of asbestos-cement pipes. Manufactured products must meet the following state standards:

1. The diameters of the pipelines must comply with the requirements in accordance with GOST 539-80.
2. After manufacturing the materials in question, they must be tested in accordance with GOST 11310-90.

During the Soviet Union, the products in question were used for the construction of reclamation canals. In those days, the use of such products for the construction of civil and industrial construction projects was not envisaged. The reason for this was a worldwide ban due to the harmfulness of asbestos. They became popular after the collapse of the Soviet Union, as chrysotile asbestos, which is harmless, began to be used for the manufacture of products. It was after this that appropriate standards were developed for the production of asbestos pipes for any needs.

In Simferopol, during the Soviet Union, an asbestos-cement highway was built, the length of which is 20 km. To construct this structure, pipes with a diameter of 700 mm were used. Today, products of this diameter are not produced.

Features of cutting products yourself

During the installation of asbestos cement pipelines, the need arises not only for connecting products, but also for cutting them. To perform this procedure, you will need to use a grinder and a diamond-coated disk.

Initially, you need to mark the place where the cutting will be done. To do this, use a tape measure, as well as chalk or a pencil. After the product has been marked (preferably along the entire outer diameter), it should be securely fixed. It is impossible to use a vice or similar devices for such purposes, as the integrity of the product will be compromised. At home, you can fix the product using two bricks or bars of the appropriate size.

After this, be sure to wear a mask or respirator to prevent inhalation of asbestos dust. A tool with any disk is suitable for cutting products of various diameters. After all, cutting will be performed sequentially along the marking line. The video below shows the process of how to properly cut asbestos products at home.

Another important point, as the possibility of connecting asbestos products using plastic couplings. Such couplings are used for products with a diameter of up to 150 mm. Connection using PVC couplings is made by heating the coupling construction hairdryer. Instead of a hair dryer, a tank with hot water, into which the clutch is lowered for 10 minutes. After this, the coupling is put on one end of the pipe, and then on the other until it stops.

Asbestos-cement products are popular. With their help, the process of constructing sewer lines is simplified not only for drainage, but also for laying communications.