In the last couple of decades, various types of plastic products are actively being squeezed with metal products market. But thanks to the durability, excellent hydraulic properties and corrosion resistance of cast iron pipeline continues to be widely used for the construction of strategic underground utilities. They are well withstand the load on the sewage network in the places of the most active use of flush valves. In addition, in cast-iron sewer pipes is much greater than that of plastic durability.
Cast iron pipe for sewer installation
In the process of construction of any structure is absolutely necessary to carry out a complex of works on laying the main underground utilities. Among the systems that are part of their composition, drainage concerns. It is the better and more durable than the best semi-finished products used in the installation. Access to the underground part of the communication facilities is often difficult. Therefore, they must be manufactured of a durable and resistant material.
The most suitable material for the installation of an underground sewage system is iron. It is great for devices of sewage companies, whose activities are due to large hydro loads:
- meat processing plants, dairies and poultry farms;
- shops catering;
- farms and slaughterhouses;
- health care institutions.
Iron, iron-based alloy with a large (above 2%) carbon content is melted by different technologies. To extract four kinds of finished metal used:
- Gray. It consists of flake graphite.
- White. Carbon in the crystal lattice of the cooled metal is in a bound state.
- High. It contains graphite in the form of microscopic molecules balls.
- Malleable. This grade is the most frequently undergoes redistribution, so has the form of graphite flakes easily fracturable.
The least popular are the products marked with the KGB, made of spheroidal graphite. The technique involves passivation of cement required to form a thin film of silicone. Products used for sanitation device reset places aggressive fecal liquids. their cost is very high, and the level of demand - on the contrary, is extremely low.
manufacture of pipes provided in compliance with the quality requirements for showering process. It is carried out in three ways:
- Semi-continuous. It lies in gradual pouring molten iron into the mold and its gradual solidification. Further extractor produced not fully solidified metal in the pipe and measuring their cutting.
- Centrifugal. Molten iron is poured into the rotating mold. At the end of casting iron cools down completely. In order to avoid accretions of surface defects and the maximum deviation of the wall thickness shall not be more than 2 mm. One variation of this method is a modern technique called casting De Lavaud.
- Casting into the chill. For pig iron uses specially manufactured form of sand (metal mold). Sand used for binding sand, clay, sodium silicate, and other substances.
To counteract corrosion pipe coated with a special composition.
The range of products from cast iron
For the manufacture of various diameters, used for assembly backbone sewage, the most appropriate composition and properties is gray cast iron. GOST 6942-98 established three types of conditional passes. Here is the table on which it is possible to determine the diameters of sewer pipes of different lengths:
|
Diameter (conditional pass), mm |
The wall thickness, mm |
Length, mm |
Weight, kg |
| 50 | 4,0 | 750 | 4,5 |
| 1000 | 5,8 | ||
| 2000 | 11,0 | ||
| 100 | 4,5 | 750 | 10,5 |
| 1000 | 13,9 | ||
| 1250 | 16,1 | ||
| 2000 | 24,9 | ||
| 2100 | 26,0 | ||
| 2200 | 27,1 | ||
| 150 | 5,0 | 750 | 15,7 |
| 1000 | 20,7 | ||
| 2000 | 39,6 | ||
| 2100 | 41,5 | ||
| 2200 | 43,4 |
Standard tables allow you to define only the approximate weight of the pipes. The actual dimensions of cast iron main sewer pipe may vary by up to 5% in the one direction or another.
Depending on the method of installation (Underground channel and gasket flange or flared way) product can manufactured and shipped to customers with or without sockets and greater length than the requirements established GOST.
Communication pressure sewer made from cast iron castings inside diameter from 65 to 1000 mm, wall thickness from 6.7 to 22.5 mm. They are much stronger than those used in the upper communication unit, and can withstand the internal pressure to 1.0 kgf / cm2. When operating such products, there is one prerequisite: cast iron products, do not expose shock loads due to the brittleness of the metal associated with high carbon content in the chemical composition. Another disadvantage of cast iron products - a large mass. This may cause some difficulties in the process of installation of trunk communications.
The most popular are the main pipe 3 meters long and spigot - for the shunt branches drain and fittings to buildings and structures:
| marking | Type of |
Length, mm |
Price for a unit, rub. |
| SML 50 | bezrastrubnaya | 3000 | 2 469 |
| SML 100 | bezrastrubnaya | 3000 | 3 840 |
| SML 150 | bezrastrubnaya | 3000 | 6 867 |
| 50 GOST 6942-98 | belling | 2000 | 1 499 |
| 100 GOST 6942-98 | belling | 2000-2100 | 2 387 |
| 100 GOST 6942-98 | belling | 2000 | 4 369 |
By type of pipe connection products are divided into three classes - A, B, and LA.
Markings on the pipes of cast iron or ductile iron CHK applied to their molded part. For the application of indelible ink is used. Location tagging - face or the back of the socket. After reading the print buyer can find the following information about the product:
- trademark of the manufacturer;
- designation characterizes the product;
- manufacturing standards.
Packaging tube of which is mounted backbone drainage, in three ways:
- packet;
- Cluster;
- ligamentous.
Cast iron products, with all the advantages of the mass have one major drawback. Metal defies bending, so for installation transitions and turning highways requires the use of various additional elements. They are called fitting. Improved mechanical properties has finished products made with modern technologies. In particular, to improve the ability to bend in the iron modifier substances are introduced during crystallization.
Separately, on pallets with boxes or containers stacked fittings for sewer installation:
- fitting;
- transitions;
- Crossings;
- pipes;
- indents;
- taps;
- tees.
Another element called revision used to clean parts weedy highways.
operating properties
Plastic, with all its advantages and low cost, it is not able to withstand such enormous loads. Therefore, it is not used for the installation of pressure sewer. Thanks to the thick walls of the cast iron products have minimal noise characteristics. The average service life of cast-iron main sewage pipes - more than half a century. Subject to the conditions of operation and carrying out timely preventive repairs possible to increase the maximum duration of the main communications services to 80-100 years.
This is facilitated by high performance cast iron products:
- resistance to corrosion film on the surface;
- High linear rate of resistance to stretching;
- excellent sound-absorbing properties;
- resistance to sharp fluctuations of ambient temperature;
- small thermal expansion coefficient.
In addition to the above properties, ready to iron castings have no seams, cracks and fistulas. This leads to an extremely high resistance of products for the installation of sewers to the physical wear and tear. Therefore, in the near future is hardly expected a massive shift during installation with a cast-iron sewer pipes on the plastic.