Dnieper asbestos-cement pipe 100, 150, 200, 250, 300, 400, 500 VT9, VT6, couplings, rings

Dnieper asbestos-cement pipe 100, 150, 200, 250, 300, 400, 500 VT9, VT6, couplings, rings

Asbestos pipes are made from two main components, which are Portland cement and asbestos fiber. Water is used to obtain a homogeneous consistency. The use of these materials makes it possible to obtain as a result a material that is light in weight and has a low thermal conductivity. Asbestos cement is a cement mortar reinforced with asbestos fibers. Asbestos goes through a grinding process to a powdery consistency, after which it is divided into fibers. It is these fibers that are the link in the concrete mix.
     The strength of asbestos pipes is obtained by reinforcing concrete with asbestos fiber. This allows you to increase the strength by 40% compared to conventional concrete devices.
A significant advantage of asbestos is its low thermal conductivity. It is due to the low thermal conductivity that asbestos pipes are used for arranging sewer pipelines with high freezing rates. A significant advantage of asbestos pipes is the absence of properties of susceptibility to electrocorrosion. 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 effect can last ten 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.
Asbestos-cement pipes are used in various areas:

     for laying sewers,
     provision of technical water supply,
     installation of drainage and storm systems,
     as casing pipes for water wells,
     to create 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.
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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Fragility is due to the fact that during rotation in the centrifuge, asbestos fibers are randomly located in the product. For a solid pipe, this does not matter, however, for shaped products it is critical.
If it is necessary to turn or branch the pipeline, cast-iron shaped products are used. When working with small diameters, the use of products made of polymers is acceptable.
The advantages of asbestos-cement pipes include:

     immunity to moisture, anti-corrosion properties (can be laid directly in the ground without additional protection, even in conditions of high humidity);
     resistance to stray currents (in underground pipelines), since the material is a dielectric;
     the smallest coefficient of linear expansion compared to all other materials from which they are made;
     fire resistance (asbestos cement does not burn, and melting begins at temperatures above 1500 ºС);
     the material also withstands low temperatures characteristic of the northern climate;
     the heat loss coefficient is lower than that of metal products;
     the inner walls of the product have an absolutely smooth surface, due to which there is no risk of “overgrowing” of the pipe, and the level of resistance of moving media is also reduced;
     a / c pipes are very easy to install and do not require special equipment;
     the immunity of asbestos cement to external influences and chemical inertness ensure a long service life;
     the cost of a / c products is lower than the price of metal ones.
Asbestos-cement pressure pipes should not have delaminations, breaks or cracks. Their ends require turning. For products whose length is 2950 and 3950 millimeters, the deviation from straightness cannot exceed 12 mm; 5 thousand mm - 18 mm; 5 thousand 950 mm - 24 mm. An important parameter of such pipes should be water tightness.
  All requirements for the production and quality of asbestos-cement products, regulated by GOSTs, are as follows:

     internal and external dimensions of asbestos pipes must comply with state standards for such products 539-80;
     test tests of asbestos-cement pipes and methods for their implementation are carried out in accordance with GOST 11310-90.

Since in the USSR asbestos-cement pipes according to GOST were used only for the construction of reclamation canals, their scope was extremely limited. That is, they were not used at any civil or industrial construction sites, respectively, and GOSTs were not published.
  The reissued SNiP regarding heat networks includes the following norms:

     According to clause 10.3 of SNiP 41-02-2003, the characteristics of heat carriers are determined that are acceptable for transportation through non-metallic pipes from which the heating network is assembled:temperature - no higher than 115 ℃, working pressure - within 1.6 MPa.
     Clause 10.4 of the same SNiP 41-02-2003 allows the use of certain sizes of asbestos-cement pipes for hot water supply systems of open and closed types.
     Based on paragraph 8.21 of SNiP 2.04.02-84 (regarding water supply), asbestos-cement pipes of any diameter can be used for the construction of pipelines for cold water supply, while additional justification is needed for the use of steel water pipes.
  In fact, asbestos cement is concrete reinforced with asbestos fibers, or fiber-reinforced concrete.

The manufacturing technology of this material is as follows:

     After mining, the raw asbestos is transported to the plant, where mechanical grinding takes place.
     The asbestos is then fluffed to separate the individual fibers.
     Next, asbestos (15%) is combined with cement (85%) and water is added to obtain a pulp.
     The liquid mixture is poured onto a perforated drum.
     After pressing, a continuous film 0.2 mm thick is obtained, the length of which is equal to the size of asbestos pipes. This film is wound on a rolling pin until walls of the required thickness are formed, which will ensure the reliability of the pipe.