Pig-iron sewer pipes. Varieties and methods of installation
Despite the appearance on the market of pipes made of polymeric materials, cast iron sewer pipes are still used. Cast iron has all the properties, necessary to ensure the proper operation of the sewer system. Most apartment buildings still have old cast iron pipelines, which proves the service life of such structures.
Cast iron pipes have their advantages and positive qualities, therefore used in modern sewer systems
Varieties of cast iron pipes for sewerage
According to technological norms, sewer pipes are made of gray cast iron. In its pure form, this metal is quite brittle and fragile, prone to microcracks. Thanks to various additives, the performance of cast iron is significantly improved. Cast iron sewer pipes are classified in the presence of impurities in the structure of the metal and the type of sewer network (pressure and non-pressure). Pipes have appropriate markings.
ВЧШГ. This abbreviation means, that the sewer pipe is made ??of high-strength cast iron with the addition of spherical granite granules. This type of cast iron can be compared in strength with carbon steel, it is quite hardy. The service life of VCHSHG pipes is very high, as metal of similar density practically does not give in to corrosion. VCHSHG sewer pipes are more often used in production systems. The needs of domestic sewage are quite able to meet the usual gray cast iron pipes.
HSHG pipes are made only with the presence of bells. Rubber sealing sleeves are used to improve the quality of their joints.
Each type of cast iron pipe has its own properties, Advantages and disadvantages
ЧНР. Cast iron pressure pipes are suitable for systems, designed to transport liquids under pressure. They are used in the same areas, as well as pipes VCHSHG, have a fairly long shelf life.
Wrinkle! The difference between cast iron sewer pipes and VCHSHG is the increased degree of fragility. Due to the low ductility of these products it is not recommended to install them with your own hands.
ЧК. Marking of the Cheka indicates pressure-free cast iron pipes for sewerage. In their production, gray cast iron with the addition of lamellar graphite is used. This type of cast iron pipe is characterized by relatively low strength. Therefore it is better to use Cheka pipes at laying of self-flowing sewer networks with small loading. At the device of internal system of a pipe of the Cheka it is possible to mount with plastic pipes by means of rubber adapters. The advantage of Cheka pipes is the possibility of secondary use after dismantling.
SML. Variety bezrustrubnaya cast iron pipes, molded cast iron and rosette graphite. Such pipes are coated with epoxy substances, additionally protects against leaks and corrosion. Trumpet-free cast iron sewer from SML pipes is very durable with proper installation. Sleeveless connection, obtained by clamps, give tight joints, that do not require additional reinforcement.
Bellless cast iron pipes have more positive qualities, than usual, one of them is the convenience of connection
SML pipes are able to withstand as high, and negative temperatures. They can be used internally, and in external sewer systems. The only condition is that, that the pipeline must be pressureless.
Advantages, shortcomings and service life of cast iron sewer pipes
Cast iron pipes can be used in almost any sewer system, their laying in the majority of types of soil is possible. Among the advantages of cast iron pipes are the following points:
- high strength;
- resistance to temperature fluctuations;
- long service life;
- resistance to flashes;
- environmental friendliness, no release of harmful substances;
- sound insulation properties;
- inertness to aggressive environments;
- low susceptibility to corrosion.
Despite the presence of many positive characteristics, cast iron pipes have a number of disadvantages. The following factors can complicate the sewer installation process:
- heavy weight;
- fragility;
- impossibility of installation without the use of special equipment and materials;
- high cost of pipes;
- significant repair costs.
For installation of the sewerage from pig-iron pipes fittings of the different sizes and forms from the same material are applied
Insufficient service life of cast iron sewer pipe may be a consequence of factory defect of the product. Not only pipes can be defective, but also fittings for connections: adapters, tees, fittings, crosses and others.
Wrinkle! Since cast iron sewer pipes are made by casting, the presence of defects in its structure can be determined by the characteristic sound. Checking the pipes by tapping, you need to watch out for that, to keep the sound tone even and loud. If in some parts of the product changes in tone are observed, means, this pipe is damaged.
Cast iron pipes have the best operational qualities, covered with petroleum bitumen. The service life of cast iron sewer pipe SML with epoxy coating increases due to increased corrosion resistance. It also matters, that petroleum bitumen makes the pipe smoother, reducing its resistance and preventing the appearance of plaque on the walls. The surface of ordinary cast iron pipes after casting remains rough.
Check cast iron pipes before installation
Preparation of cast iron products is the most important stage in the repair or installation work. In the first place, transportation of such pipes should be very careful because of the fragility of the material.
Transportation and laying of pipes are very responsible processes, as it is very easy to damage a cast-iron pipe at careless handling
Even if at first the design did not have factory defects, but was damaged during transportation, in the future, the pipeline may burst under the action of water at the site of the defect. Even falling from a small height can damage the cast iron pipe.
To avoid repairing the system immediately after startup, the following steps must be taken before installation:
- check the edges of the pipes and bells for irregularities;
- inspect the product along its entire length - the specified diameter must be maintained along the entire length of the pipe;
- assess the quality of bituminous coating: it must not be sticky or become so when heated;
- make sure that the workplace has tow and cement for sealing the bells (if a sewer is installed).
After assembling each section of the pipeline, it is desirable to tap. This will make it possible to assess the accuracy of assembly and reliability of fasteners. As a result, a properly assembled system should sound complete. If you do not hear any sections when tapping, means, an error was made in these places.
Connections of cast iron sewer pipes: basic requirements
Each method of connecting pipes has its own subtleties and rules.
The bell connection is more time consuming, than bellless, but if done correctly, you can achieve complete tightness
Bell sewer. The most common method of joining cast iron pipes is to connect them to the bell. When assembling the equal part of the pipe is inserted into the expanded part of another segment. The connection technology is the same for cast iron pipes of any diameter, the main task is the high-quality sealing of the bells. Gap, which appeared between sections of pipe, clog up with tar. The tow must be compacted before filling 2/3 the size of the bell. This should be done slowly, with a wooden spatula and hammer. 1/3 the remaining depth is filled with sealant.
Wrinkle! Kabolka, an organic fiber, is most often used as a sealant. It is not necessary to impregnate it with anything, as oil mixtures can impair adhesion to cement, which will greatly reduce the service life of the connection.
The last stage of work will be centering of a pipe in a socket by means of wooden wedges and filling of depth with cement of mark 300-400. Bituminous mastic is sometimes used instead of cement, clay or asbestos-cement mixture. In this case, the joint is smeared as it dries with oil paint. For better curing, the compacted cement is covered with a wet cloth.
Sewerless sewer. Installation of the sewer from bezrubrubny SML elements demands much less expenses of time. Only clamps are required for connection. They are common (connectors), are applied to sewers with pressure in 0,5 bar and amplify. The latter type of clamps is used, if the pressure in the system reaches 10 there is. Service life of cast iron sewer pipe, installed in this way, quite large due to the ease of repair of the system. The damaged section of the pipeline can be quickly dismantled and replaced. To do this, simply loosen the fasteners on both sides of the segment.
Cast iron pipes are reliable and durable products, used for drainage systems in the home and industry. Choosing the type of pipes, the purpose of the future pipeline should be taken into account and special attention should be paid to the process of connecting cast iron elements.
