Despite the appearance on the construction market of plastic pipes, cast iron pipe products, still in demand. The use of special additives brings the strength of such products to a new level. On the basis of cast iron water pipes GOST 9583 75 water mains are created, which can be laid underground. However, in indoor plumbing they can be found very rarely due to low aesthetics.
Cast iron bell pipes are a popular material for drainage systems
Assortment of cast iron pipes
In accordance with GOST 9583 75 depending on the wall thickness of cast iron pipes are divided into the following 3 groups:
- "A". 7,4 ?Ѕст ? 28,4 mm.
- "LA". 6,7 ?Ѕст? 22,5 mm
- "B". 8 ?Ѕст? 28 mm, de Ѕst. - wall thickness.
Parameters of cast iron pressure pipes of group "A" with connection of bell type GOST 9583 75 are listed in table №1.
Table 1
| Outer diameter, millimeters | Conditional passage, millimeters | Wall thickness, millimeters | Meters in tons | Mass 1 meters, kilograms |
| One thousand forty-eight | One thousand | 24,8 | 1,73 | Five hundred and seventy-two |
| Nine hundred and forty-five | Nine hundred | 22,3 | 2,08 | 480,9 |
| Eight hundred and forty-two | Eight hundred | 21,1 | 2,53 | 394,6 |
| Seven hundred and thirty-eight | Seven hundred | 19,3 | 3,16 | Three hundred and sixteen |
| Six hundred and thirty-five | Six hundred | 17,4 | 4,08 | 244,8 |
| Five hundred and thirty-two | Pyatsot | 15,6 | 5.45 | 183,5 |
| Four hundred and twenty-nine | Four hundred | 13,8 | 7,66 | 130,5 |
| Three hundred and seventy-eight | Three hundred and fifty | 12,8 | 9,39 | 106,5 |
| Three hundred and twenty-six | Three hundred | 11,9 | 11,74 | 85,2 |
| Two hundred and seventy-four | Two hundred and fifty | 11,0 | 15,7 | 65,9 |
| Two hundred and twenty-two | Two hundred | 10,1 | 20,49 | 48,8 |
| One hundred and seventy | Hundred and fifty | 9,2 | 29,67 | 33,7 |
| One hundred and forty-four | One hundred twenty five | 8,7 | 37,31 | 26,8 |
| One hundred and eighteen | A table | 8,3 | 48,08 | 20,8 |
| Ninety-eight | Eighty | 7,9 | 61,73 | 16,2 |
| Eighty-one | Sixty-five | 7,4 | 80,65 | 12,4 |
Parameters of cast iron pressure pipes of LA group with bell-type connection. GUEST 9583 75 are listed in table №2.
Table 2
| Outer diameter, millimeters | Conditional passage, millimeters | Wall thickness, millimeters | Meters in tons | Mass 1 meters, kilograms |
| One thousand forty-eight | One thousand | 22,5 | 1,9 | 525,6 |
| Nine hundred and forty-five | Nine hundred | 20,6 | 2,28 | 437,8 |
| Eight hundred and forty-two | Eight hundred | 19,2 | 2,78 | 359,9 |
| Seven hundred and thirty-eight | Seven hundred | 17,5 | 3,48 | 287,2 |
| Six hundred and thirty-five | Six hundred | 15,8 | 4,49 | 222,9 |
| Five hundred and thirty-two | Pyatsot | 14,2 | 5,97 | 167,5 |
| Four hundred and twenty-nine | Four hundred | 12,5 | 8,44 | 118,5 |
| Three hundred and seventy-eight | Three hundred and fifty | 11,7 | 10,25 | 97,6 |
| Three hundred and twenty-six | Three hundred | 10,8 | 12,89 | 77,6 |
| Two hundred and seventy-four | Two hundred and fifty | 10,0 | 16,64 | 60,1 |
| Two hundred and twenty-two | Two hundred | 9,2 | 22,42 | 44,6 |
| One hundred and seventy | Hundred and fifty | 8,3 | 32,79 | 30,5 |
| One hundred and forty-four | One hundred twenty five | 7,9 | 40,82 | 24,5 |
| One hundred and eighteen | A table | 7,5 | 52,91 | 18,9 |
| Ninety-eight | Eighty | 7,2 | 67,11 | 14,9 |
| Eighty-one | Sixty-five | 6,7 | 88,5 | 11,3 |
Parameters of cast iron pressure pipes of group "B" with connection of bell type GOST 9583 75 summarized in the table 3.
Table 3
| Outer diameter, millimeters | Conditional passage, millimeters | Wall thickness, millimeters | Meters in tons | Mass 1 meters, kilograms |
| One thousand forty-eight | One thousand | Twenty-seven | 1,59 | 627,9 |
| Nine hundred and forty-five | Nine hundred | Twenty five | 1,91 | 523,9 |
| Eight hundred and forty-two | Eight hundred | Twenty-three | 2,33 | Four hundred and twenty-nine |
| Seven hundred and thirty-eight | Seven hundred | Twenty one | 2,92 | 342,9 |
| Six hundred and thirty-five | Six hundred | Nineteen | 3,75 | 266,6 |
| Five hundred and thirty-two | Pyatsot | Seventeen | 5,02 | 199,4 |
| Four hundred and twenty-nine | Four hundred | Fifteen | 7,07 | 141,4 |
| Three hundred and seventy-eight | Three hundred and fifty | Fourteen | 8,61 | 116,1 |
| Three hundred and twenty-six | Three hundred | Thirteen | 10,79 | 92,7 |
| Two hundred and seventy-four | Two hundred and fifty | Twelve | 13,97 | 71,6 |
| Two hundred and twenty-two | Two hundred | Eleven | 18,9 | 52,9 |
| One hundred and seventy | Hundred and fifty | Ten | 27,47 | 36,4 |
| One hundred and forty-four | One hundred twenty five | 9,5 | 34,36 | 29,1 |
| One hundred and eighteen | A table | Nine | 44,84 | 22,3 |
| Ninety-eight | Eighty | 8,6 | 57,14 | 17,5 |
| Eighty-one | Sixty-five | Eight | 75,19 | 13,3 |
The normative document states, that in pressure water supply networks use of only bell-shaped pig-iron pipes is allowed.
Production of bell products
These ferrous metallurgy products are manufactured using two technologies.
Casting technologies are used for the production of pipes, which consist in pouring liquid cast iron into special molds
Centrifugal casting. Pouring into a rotating form of liquid cast iron under the action of centrifugal force spreads along the walls and crystallizes.
Useful to know! The amount of metal poured directly affects the wall thickness, and the shape of the product acquires any complex shape.
Advantages of centrifugal casting of pipes of pig-iron pressure head bells of GOST 9583 75 should be attributed:
- high performance;
- improved characteristics of cast iron;
- saving raw materials and energy;
- possibility of full automation and mechanization of the process;
- no need to organize additional sites for formation. The same applies to equipment for drying molds: it is not required.
The main disadvantages are as follows:
- so that the wall came out the required thickness, cast iron should be strictly dosed;
- in the casting process, regulated by the requirements of GOST 9583 75, special expensive machines and sealed forms of the increased durability are used. The need for such equipment increases the cost of products;
- the finished product acquires only the form of rotation.
Semi-continuous casting. This technology is the free pouring of liquid iron into the mold-mold. There it cools and hardens. Partially cooled pipe is slowly removed from the mold. Allow the workpiece to cool completely, it is cut and thus obtain products of the required length. Running water is used to cool the mold. Pipe extraction is carried out on the equipment, representing a table, which is gradually moving down.
The positive aspects of this technology include:
- metal savings;
- reduction of costs for replacement equipment;
- exact geometric dimensions;
- the possibility of producing long pipes.
Long cast iron pipes are made by semi-continuous casting
Of the negative aspects should be noted:
- complex extraction mechanism;
- the complexity of obtaining the workpiece.
Types of cast iron
All cast iron pressure pipes are characterized by high strength and ability to operate for a long time. The plasticity of the material allows it to withstand high pressure. Properties of raw materials, actually, and determine the operational potential of the cast iron pressure pipe GOST 9583 75.
Today the following types of cast iron are used in metallurgy:
- White cast iron. Not susceptible to defamation (graphitization). Despite this, this metal is resistant to corrosion and wear. Usually, it serves as a raw material for the production of materials of another kind.
- Gray cast iron. It is characterized by high molecular weight and greater strength due to the fact, that its molecular structure contains lamellar graphite particles. However, fragility complicates installation work.
- Ductile iron. Contains flaky graphite additives. Being one of the varieties of white cast iron, this material has ductility and high strength.
- Cast iron VCHSHG. This abbreviation means high-strength cast iron with spherical graphite. Due to the presence in the metal molecules of particles of this additive, casting properties of pipes, manufactured in accordance with the requirements of GOST 9583 75, significantly improved. It is from VCHSHG that the strongest production of pig-iron pipe metal of pressure head type is made.
The strongest pipes are made of cast iron with spherical graphite - VShCHG
Asbestos cement is used for sealing joints during installation.
Importantly! It is necessary to monitor this, to make the joints flexible. If increased seismic activity is recorded in the region, the joints must be further reinforced with couplings and pads and the joints closed with rubber rings.
Advantages and applications
Cast iron pressure pipes GOST 9583 75 reliable and durable (service life - about 100 years). Their outer surface is covered with a layer of petroleum bitumen, and they easily adapt to any climatic conditions. Such products are different:
- corrosion resistance;
- bending strength;
- resistance to shock loads;
- high elasticity;
- resistance to cracking.
U GOST 9583 75 indicated, that sewerage systems are created on the basis of cast iron pressure pipes, heating, gas - and water pipes of large diameter, are intended for transportation of various liquids under pressure. Laying can be underground and aboveground, channelless and channel. In general, it is recommended to use these rolled metal products there, where the presence of loads is assumed, significantly exceeding household. In particular:
- in slaughterhouses and meat processing plants;
- in the food industry;
- in educational institutions, sanatoriums and hospitals;
- in places where large numbers of animals are kept, example, on farms;
- at public catering establishments;
- for gas and water supply to neighborhoods and neighborhoods of cities and towns;
- for arrangement of storm drains and main sewer pipelines;
- in fire protection systems;
- in laboratories.
Cast iron bell pipes are used not only for installation of internal, communications, but also external, including underground
in addition, pipe products of this type are used as concrete piles to strengthen the soil during the construction of buildings and construction in ports.
Quality requirements
The transition of the cylindrical surface into the bell is allowed to perform with a slope or in the form of a ledge. Deviation of the sizes of pipes of pig-iron water GOST 9583 75 from nominal values can vary within the following limits:
- wall thickness -1? Ѕст ?+0,5 mm;
- length of measuring tube - plus / minus 20 mm;
- the size of the inner diameter of the bell is equal to: (1,50 + 0,002 Dн) ? Dvn ? + (2,50 + 0,002 Dн), of Dn. - nominal diameter;
- outer diameter (more 300 mm);
- outer diameter (no more 300 mm inclusive) - plus / minus (4,50+0,0015 Dн.).
The degree of ovality of cast iron water pipe GOST 9583 75 should not deduce its sizes for maximum admissible indicators, and the actual weight of the product should not exceed the estimated more than 5%. Pipes are subjected to hydraulic tests taking into account their nominal size and class. Test pressure of cast iron pressure pipes GOST 9583 75 are presented in table №4.
Table 4
| Diameter, millimeters | Test pressure level, kg / cm2 | ||
| Class LA | Class A | Class B | |
| More 600 | twenty | Twenty five | Thirty |
| 300-600 | twenty | Thirty | Thirty-five |
| 300 and less | Twenty five | Thirty-five | Fourty |
pay attention! The level of working pressure in water supply pipelines does not exceed, usually, 3… 4 atmospheres. Rise to value 8 or even 10 kgf / cm2 (the same numbers in technical atmospheres) it can only after reloading the engineering system within the neighborhood or at home.
Pipes are being prepared for shipment to the customer, which have been tested for quality and meet the requirements of the Guest
The opposite end of the pipe should be cut perpendicular to the longitudinal axis. Permissible deviation - no more 0,5 degrees. A layer of protective non-toxic material is applied to the outer and inner surfaces. The coating must maintain the tightness of the joint, do not soften or peel off, even if the liquid temperature reaches +60?WITH. However, the customer has the right to refuse to apply a protective layer on the ordered batch of pipes.
Methods of connecting cast iron pressure pipes GOST 9583 75
Elements of high pressure pipelines, made of pipes, which are connected in the following ways;
- Titon bell connection. This method involves the installation of a two-layer seal in the socket. Installation is performed using a special device. A similar method is used to connect cast iron pressure pipes GOST 9583 75 in highways with internal pressure, not exceeding 1,6 MPa (16,315 atmosphere);
- bell-shaped fixed connection of HRV ("Thiroflex"). Scope - installation of vertical pipelines and laying of heating systems, water supply and sewage transportation on unstable soils and in the mountains. A sealing ring is placed in the socket, and the connection procedure ends with the installation of stoppers in the recesses. This technical solution allows the pipeline to move without depressurization at an angle of about 1,5-5 degrees;
- flange connection. This method is used in the installation of inspection channels and pumping stations, as well as when it is necessary to build an underground pipeline, able to transport fluid under pressure above 2,5 MPa (24,675 atmosphere). A sealed double-flange seal ensures a tight connection. Fixing of flanges to pipes is carried out by welding. The joints are welded on the outside, and inside;
- welded joint. This type of connection is formed in heating systems and plumbing with operating pressure, not exceeding 1,6 MPa. In the territory of our country welding of pig-iron pipe elements has not found wide application. The reason lies in the banal lack of competent professionals and the shortage of electrodes with nickel and iron-nickel. They are not produced in our country.
The simplest is the pipe connection, as it does not require the use of welding equipment
Assembly of cast iron pipeline
It is easy to mount a pipeline from such pipes, you only need to strictly follow the procedure:
- first, the end of the next is inserted into the bell of the previous pipe. Moreover, the direction of the bell should be oriented against the flow of liquid;
- then the lower and upper pipes are fixed on the support surface;
- the next stage is the insulation of the joint between the smooth end of the upper pipe and the lower bell;
- completing the procedure of sealing the joint, fix the upper pipe as tightly as possible on the support surface. After that it is possible to start installation of the following segment, which is inserted into the socket of the already fixed pipe.
Importantly! The lower part of the pipeline must be fastened tightly, and the top - with a gap, which will allow you to rotate the pipe.
The connection of the trunk element with the shaped part is similar: that is, first the smooth end of the pipe is inserted into the socket of the fitting. And then - the same sequence of actions with adjustment to smaller dimensions of the shaped part. The quality of the connection is largely determined by the correctness of the joint stamping procedure. Therefore, we will dwell on this issue in more detail.
Closing the bell
Good and correct pipe connection is very important. First of all, this applies to the reliable sealing of the bell.
That the joint of pipes was tight, it is necessary to lay it by means of sanitary flax, and then fill with cement mortar
To perform this operation, a high-quality tow made of hemp fibers is used. It should not contain wood or any impurities, otherwise complete sealing will not be provided, and pipes will leak at the joints. If an asbestos-cement mixture is used for clogging, pre-tarred hemp strand rolled into a bundle is introduced into the bell. The thickness of the harness should not be much more than the bell slit.
The harness in the gap of the bell is legalized (compacted with a hammer and caulk. It is necessary to control, so that the strand is removed from the end of the bell on 30 millimeters. Ingredients are included in the mixture of asbestos cement in the following proportions: Portland cement brands 400 (it is possible and above) – 70%, asbestos fiber (grade 4 and above) – 30% of the total mass. Before use (minutes 30-40) the mixture is moistened by adding water. From the total weight of the dry mixture, it should be 10-12%.
Another way to earn a bell is to use waterproof expandable cement. This is a more advanced method of assembling cast iron structures. This material is characterized by water resistance, as well as the ability to expand and self-seal during curing. Due to the lack of need to mint and caulk joints, the procedure of closing the bell takes a little time. The work is carried out in the following sequence:
- winding before blowing white strands. The following requirements must be met: diameter of pipes 50 mm - two strand-thick screws are wound 5 and length 440 millimeters; diameter of pipes 100 mm - the same thickness, and length - 70 millimeters;
- draft thin caulk belts in the bell;
- centering of a design by means of three metal wedges.
- laying with cement: diameter 50 mm: volume of cement - 100 city.; pipe diameter 100 mm: amount of cement - 200 In both cases, water must be added to 70 percent of the volume of cement.
Importantly! To create a uniform gap on all sides, wedges must be driven between the bell and the pipe with light blows of a hammer.
Tees are used to branch the pipeline, which are also connected to the pipes by the "bell" method
Often there is a need to change the direction of cast iron pipelines, installation of various fittings and creation of branches. Shaped details are used for this purpose: couplings, issues (serve to empty the pipes), flange and bell pipes, crosses and tees, knees and elbows. At arrangement of a water supply network on the basis of pipes of pig-iron pressure head bells of GOST 9583 75 the use of connecting parts is allowed, made by welding of sheet steel, as well as other similar products.
Connection of cast iron pipes with plastic ones
It should be noted, that connection, created using special fittings, in this case does not differ in durability. The reason - at high temperatures, plastic expands less than cast iron. As a result, the connection will be uneven, which can cause the fitting to fail. Therefore installation is carried out by means of the socket available at the ends of pipes. This work does not require welding. Tightness of a design provides the dense rubber ring serving as a sealant, which is installed in the bell. Fastening of pipes to a wall is carried out by means of collars. It would seem, everything is very simple. However, we should not forget about some nuances. So, example, when working with cast iron pressure pipe GOST 9583 75 the use of a hammer with a metal tip is not allowed. This is due to the fact, that part of the material may just break off and, getting inside the highway, clog it. It is recommended to use a hammer with a rubber or wooden nozzle.
In conclusion, it should be said, that the appearance of plastic pipes for water supply has not reduced the relevance of cast iron pipes. They are widely used today.