All about pipes in construction. Construction of main pipelines - methods and stages of work

Used pipes are suitable for a range of residential, engineering and industrial construction applications. In terms of strength and tightness, they are not inferior to new ones, but at the same time much cheaper. The degree of wear depends on the scope of the original application - what kind of raw material went through the pipeline before dismantling. This is one of the criteria that you should pay attention to if you want to buy a used pipe.

What goals in construction do used pipes solve?

1. Installing a new foundation or restoring an old one.

Piles are made from boo pipes for pile foundations and structures on a reinforcing cage. pile foundation needed if there are mobile soils on the site to be built, high level groundwater or if the construction of a monolith is difficult. The old foundation will become more durable and stable thanks to the "pipe" strengthening.

There are many types of piles. Tubular material is often used to make screw piles, which underlie light structures - fences, fences, small outbuildings.

For the construction of bridges (river, sea), bored, bored injection piles are used.

And to create a reinforcing cage, the boo-pipes are cut into rings and strengthened with them metal bars. Such a frame ensures the strength of the piles and uniform distribution of the load.

2. Development of pits.

So that the dug pit does not crumble and groundwater does not get into it, the soil is strengthened. Used pipes act here in two qualities:

• perimeter fence. They are hammered into the soil and form a supporting wall, which prevents the pit from “sliding” and collapsing. Such a fence is called sheet pile;
• spacer. It is needed so that the earth does not squeeze out the tongue, it can go in several tiers. Spacer systems are used for deep and complex pits. The design consists of spacers and strapping belts. The latter are made of a channel or an I-beam.

3. Strengthening the coastlines of rivers and seas.

One of the bank protection materials is a metal pipe sheet. It is light in weight, quick to install and does not require pre-digging. This method of bank protection is cheap, the composition of the soil does not affect the installation, and, if necessary, the fence is quickly dismantled.

4. Construction of hydrological structures.

As a sheet piling, bu pipe material is used in the construction of berths, docks and ports. Hydrological structures are found in hydroelectric power plants, dams, pumping stations, shipping locks, etc.

The pipe pile is very durable and absolutely tight, which is important when working with water. He is protective wall with locks attached to them.

5. Removal of technical water and storm sewerage.

Often necessary conditions construction works is a decrease in the level ground water. This is a kind of guarantee that the object will not be damaged by water, will not be flooded. Artificial drainage is required for pits, roads, other underground and surface structures.

Bu pipes provide free flow of industrial liquids and rainwater.

6. Pontoons and other floating structures.

A pontoon is a "raft" made of tubular material. For this purpose, boo pipes that are welded together are suitable. Among the advantages of such buildings are strength, ease of transportation, stability due to the weight and diameter of the pipe material. If necessary, repairs are possible.

The main types of pontoons:

• for technical needs;
• mooring piers;
• boat stations;
• floating gazebos;
• for rest houses and tourist bases;
• floating objects (cafes and restaurants, houses, dachas, baths, etc.).

7. Foundation of lighting poles.

Pipes previously used used as a mortgage part of the foundation for lighting structures. More often they are used in small load-bearing structures, however, they are also used in power lines (power lines).

To install supports, you need to think over the foundation in advance. type and dimensions, bearing capacity pipe supports are selected according to the calculations individually in each case. In particular, the region of operation is taken into account.

8. Cases for cables, pipes, other utilities.

The case acts as a protective shell. In this sense, used pipes with a diameter of 219 mm and above are suitable. The pipe-case protects against pressure and vibrations, from water and other aggressive media.

A typical technique that is used to lay a pipe-case is called "puncture". To begin with, 2 pits are prepared - outgoing and receiving. Then the used pipe is cut into pieces of 2.5-3 m in length. The resulting “coils” are pushed through the soil one by one into the receiving pit (when the first part is completely immersed in the soil, the next one is welded to its end, etc., until the pipe is completely extended).

The soil is removed from the case mechanically, and then insert communications into it, etc. The space between the outer and inner pipes poured with concrete.

9. Electrochemical protection of underground pipelines.

Metal pipelines lying in the ground are subject to corrosion. Used pipes are used to protect them and extend their service life. The mechanism of electrochemical protection is based on two principles:

• case;
• electrochemical reaction of the cathode and anode.

To protect the pipeline from rust, it is necessary to generate a cathodic reaction and eliminate the anodic one. The protected object is the cathode, a negative potential is created on it. And an anode is made from a pipe-case. To close the circuit, the positive pole is connected to the negative. The anode performs the function of grounding, and the corrosion process is suppressed.

10. Design of screw conveyors.

The screw conveyor at the construction site is designed to smoothly supply fine mixtures. The mechanism of the device is simple: a solid screw with wide blades moves in the body-pipe, which move the contents.

Best for auger body seamless pipe. In second place is a pipe with one straight seam or spiral welding. For the construction of screw conveyors, pipes are used from under gas, steam, restored or stale. All of them have a clean, flat surface.

11. Creation of slurry pipelines.

A slurry pipeline is a kind of analogue of a drainage system. Only instead of water, it removes pulp - a mixture of soil, rock and water. Pulp is formed in situations where construction and mining operations are carried out with the use of water or in aquatic environment. The length of the slurry pipeline can reach several kilometers. From this it becomes clear that boo pipes are suitable and cheap way solution to this problem.

12. Country construction.

Used pipes solve the problems of private suburban buildings. They are simply connected to each other and can be easily combined with sheet metal. Used pipes are widely used in the construction of fences, frames of wells and wells, chimneys and ventilation ducts. They are successfully used for arches, gates, gates and doors, as frames for garages and sheds.

Pipes are the main conveyors of all kinds of communications to the premises. There are: copper, cast iron, brass, steel and polymer. Each type of pipe has its own characteristics and applications. Which we will consider below.

Copper pipes are the most common in communications, because. even chlorine, which purifies water by layering on inner surface pipes extends the service life of communications. They are durable, resistant to sudden temperature changes and the effects of high and low temperatures, inert to water, do not emit harmful substances, and the soldering and welding of pipes is quite strong. Easy to install, however, expensive.

Cast iron pipes

Cast iron pipes are heavy, which makes installation difficult, but they are very durable. There are: non-pressure, flange pressure, fan, non-pressure drain, soda pressure, socket pressure. They, like copper ones, withstand temperature extremes, are resistant to the influence of water and its components, and so on, but their resistance threshold is higher.

Brass pipes are made from an alloy of copper and zinc, so they have the properties of both metals, complementing each other. Some additions with other metals increase certain properties, for example, corrosion resistance when tin is added.

Brass is chrome-plated, which gives an aesthetic appearance; such pipes and details of communication structures are placed where it is impossible to hide them.

Steel pipes

Steel pipes are the main material that was used before, but such disadvantages as the impossibility of installation without the use of welding, susceptibility to corrosion, growth limescale, which significantly reduces the throughput and high weight make it necessary to refuse the choice of this type of pipe. There are galvanized and pipes with electroplated, mounted on a thread, which remove imperfections, however, do not reduce weight.

Steel pipes

Polymer pipes

Polymer pipes, depending on the composition and additions, are intended for different kind communications: polyethylene (water and gas pipelines underground), polyvinyl chloride (water supply, withstand up to 45 ° C), reinforced ( drinking water and heating), heavily chlorinated (water supply, withstand up to 90 ° C).

Polymer pipes

What thoughts do we have when we see giant chimneys releasing black clouds into the blue sky? Perhaps, first of all, these will be thoughts about the complex relationship between nature and civilization.

Oleg Makarov

However, until mankind has learned how to get rid of gaseous waste from enterprises and power plants, without throwing these wastes far into the atmosphere, pipes will be built, and the construction of these structures will remain the most difficult and interesting engineering task.

The highest chimney in the world was built in 1987 in the USSR, and is now located on the territory of Kazakhstan. To a height of 420 m, it diverts emissions from the Ekibastuz GRES-2, which generates electricity from local high-ash coal. This pipe is slightly inferior in height to the Canadian Inco Superstack with its 385 m, erected in 1971.

In the 21st century, nothing like this was built - today the emphasis is on treatment facilities, which seriously reduce the toxicity of emissions. This, however, does not mean that pipes have lost their relevance - it just became possible to build them lower, but not so much: pipes above 200 m are being built today. They are not as spectacular as skyscrapers, but many of the engineering problems that must be solved in the construction of ultra-tall buildings are also present in the work of pipe layers - yes, that's what the chimney builders are called.

One of the final stages of pipe construction is its coloring. There can be no liberties here: the pipe is a high-rise object and must be clearly visible to the crews of aircraft.

Brick receded

The classic and very first material for the construction of chimneys was brick. While the pipes remained low, everything was fine, but as their height increased, it turned out that the brick had its own strength limits and did not work well in compression. However, if you choose a stronger brick and binder mortars with special qualities, then records are possible in this area. Back in 1919, the American company Custodis Chimney in the city of Anaconda, Montana, erected the tallest in the world brick pipe to remove gases from a variety of copper smelting furnaces. The pipe has a conical shape (diameter 23 m at the base and 18 m at the top) and goes into the sky at 178.3 m. Its thickness brick walls at the base is 180 cm.

This record holder had no followers. In the coming decades, the most popular structural material became reinforced concrete. Reinforced concrete pipes are still being built, although there are already alternatives in the form of metal and plastic. To find out what modern giant chimneys are like, PM went to St. Petersburg, where the headquarters of CJSC Korta is located. This company designs and builds tall chimneys, cooling towers, as well as repairs and maintains them in 40 regions of Russia.

When erecting a reinforced concrete pipe in winter time, especially when it comes to sliding formwork, the construction site is surrounded by the so-called greenhouse, where the positive temperature is maintained with the help of a heater.

“Videos on the Internet, in which young people thirsty for adrenaline jump from high tubes with bungees and parachutes, are perceived without enthusiasm in our professional environment,” says Alina Smirnova, CEO CJSC Korta. “Those daredevils take risks for the sake of risk, and the work of a pipe-layer involves risk by necessity. Until now, working at height is hard, mostly manual labor, where inattention and neglect of safety precautions can cost lives.” A cubic meter of concrete poured near the ground and a cubic meter of concrete poured at a height of 150 m differ enormously in cost, experts tell us. To verify the validity of this statement, it is worth understanding how a modern reinforced concrete chimney is arranged and how it is built.

Getting closer to the sky

Everything, of course, begins with the foundation, and here analogies with a skyscraper suggest themselves. like a core high-rise building, a chimney is a rod, cantilevered at the base. Both under the future pipe and under the future skyscraper, concrete slab. The slab may or may not be supported by piles, but in the latter case, its area will have to be significantly increased. Since chimneys are built, as a rule, in cramped conditions in industrial areas, piles are usually used. A so-called glass is installed above the stove - the round base of the future pipe.

A lifting head is installed on the shaft elevator (lattice structure), to which a working platform with external formwork will be attached.

The construction of a pipe is somewhat similar to monolithic construction buildings - it gradually grows upwards. The only difference is that at the disposal of the pipe-layers are not spacious floors, but a space limited by the diameter of the pipe - only a few meters. There are two main pipe construction methods, climbing formwork and sliding formwork. The first method is technologically simpler, cheaper, but inferior to the second in the speed of work and in the quality of a reinforced concrete pipe shaft.

If the pipe is erected using the climbing formwork method, then on the foundation (inside the future pipe) an stackable lattice structure is installed - a “mine elevator”. It is used to climb building materials(reinforcement, concrete), and also serves as a support for the electromechanical lifting mechanism - the "lifting head". A round platform is suspended from the head, from which the outer part of the formwork hangs. The internal (adjustable) part of the formwork is mounted additionally. The formwork is assembled, fixed, reinforcement is installed in it, concrete mortar. After the concrete hardens and gains structural strength, the head raises the platform by 2.5 m. Everything is repeated again. Thus, the pipe grows in rings, and each of these rings has an internal ledge, the so-called console. Why is she?

What are the pipes crying about?

The fact is that in addition to the outer barrel of a reinforced concrete pipe, there is also an inner shell, the so-called lining. It is made, as a rule, from fire and acid-resistant bricks. The lining (in domestic designs) also consists of separate rings, each of which rests on its console. In western pipes, the lining is usually a one-piece separate barrel, which is installed inside the main one. Between the lining and the reinforced concrete shaft, a heat-insulating layer is made of mineral wool, or even just an empty void.

The task of lining and thermal insulation is to save the reinforced concrete shaft from the action of exhaust gases. Firstly, gases are very hot; in glass production, for example, their temperature sometimes reaches 400 °. But more than that, the exhaust gases also have aggressive properties. They most often contain sulfur compounds. “If the pipe is designed incorrectly or its operating conditions are changed,” Alina Smirnova explains, “then a very unpleasant thing can happen: a “dew point” zone will appear right in the pipe shaft at a certain height and gaseous waste will begin to condense. It must be understood that in the presence of water vapor, which is always present in the pipe, sulfur compounds can give sulfuric acid, and acid rain will fall right in the pipe. Aggressive condensate flowing down the lining is a great danger. With a strong temperature difference between the gases inside the pipe and the air outside, moisture migration occurs: condensate penetrates into the reinforced concrete shaft and corrodes the reinforcement and stone.

Construction of the final part of the foundation under chimney- the so-called glass. First, the reinforcement is mounted, then the concrete form is created.

Sometimes he performs outer surface pipes in the form of whitish spots, and in winter period turns into huge icicles. Then they say: the trumpet is crying. To exclude such phenomena, the lining is covered special formulations reducing its permeability to condensate. But in pipes that exhaust gases during coal combustion (in Russia there are many coal mines and many thermal power plants with them), the protection of the lining occurs naturally: the plaque that forms perfectly protects the brick.

Not cheap sliding

In the 1960s, a more advanced technology for the construction of reinforced concrete pipes was developed in Sweden - the sliding formwork method. In this case, the working platform with the formwork moves from zero, rising on jacking rods that remain in the concrete body. The formwork height is 1.2 m, but the concrete is laid in layers of 20–30 cm. As soon as the layer acquires a structural strength of 5 MPa, the next one is laid. The sliding formwork method makes it possible to build up a pipe under construction by 3 m or more per day, the process is almost continuous, and there is no need to disassemble and assemble the formwork.

“However, this is a complex and expensive technology,” says Andrey Kuznetsov, production director of CJSC Korta. “Slipform pipe construction equipment is produced by only two companies in the world, and its operation is so complicated that we have to use it only under the supervision of foreign supervisors representing the manufacturer. Only the Austrians know how to build conical structures by this method. In addition to high cost, in Russia the sliding formwork method has two more disadvantages. First, it is almost impossible to use sub-zero temperatures(due to constant supply liquid solution, which can freeze), and secondly, the technology involves the uninterrupted supply of the solution for, say, two months, and not in every region of our country production capacity allow this."

But no matter how complex the formwork technology is, working at height makes people high requirements. If the pipe under construction is not equipped with elevator equipment (and it is not installed up to certain heights), only climbing to a height of 100-150 m is a decent waste of time and effort. Working at height is not easy and psychologically - the fear of heights is inherent in a person from birth. As we were told, some pipelayers, who successfully work on 120-meter pipes, flatly refuse to work on 200-meter pipes. Scary! Upstairs on small playground there is no place for heavy equipment - workers use wheelbarrows and many other things to pour mortar into the formwork hand tool. A cube of concrete, poured at a height, is also made “golden” by the need to ensure the safety of pipelines, and this costs a lot of money. “Savings on security allow some companies to offer low prices, - says Andrey Kuznetsov, - but in the end this can lead to tragic consequences, such as the death of three workers during the repair of the Konakovskaya GRES pipe in May this year. People fell down with the cradle, which, obviously, did not pass the required tests.

iron argument

However, there is an alternative to reinforced concrete pipes with their labor-intensive technologies - metal constructions. Metal pipes are freestanding (in this case, a lot of metal is needed) or fixed in a carrier portal that looks like a lattice truss. The construction of such pipes is technologically simpler, they are more maintainable, but less durable.

"Choosing for metal pipe should be based on economic calculations,” Andrey Kuznetsov explains. - If a reinforced concrete pipe is built up, then the metal must be assembled from the ring elements using cranes. Cranes capable of lifting pipe parts to a height of 150 m are unique machines, the rent of which can cost a million rubles a day or more. To reduce the cost of the process, we are now experimenting with another technology. A lattice easy-to-assemble truss is built over the entire height of the pipe, and then a pipe of metal rings is mounted inside it. It is built up either from above (then the sections are lifted up with a winch) or from below (then the constructed part of the pipe is lifted on jacks). In this case, heavy cranes are not needed.”

July 25, 2016
Specialization: master of internal and outdoor decoration(plaster, putty, tile, drywall, lining, laminate and so on). In addition, plumbing, heating, electrical, conventional cladding and balcony extensions. That is, repairs in an apartment or house were done on a turnkey basis with all necessary types works.

HDPE pipes for water supply in the country or in country house are the most popular, for several reasons. However, this does not mean at all that there are no other options - they definitely are, and we will consider them. I will also tell you how to organize a water supply system with a submersible pump for a well or a well, I am sure the information will be informative for many. Let's get down to business right away!

Pipe selection: 4 best options

There are a lot of materials from which you can make plumbing or sewerage with your own hands, but I wanted to single out only four types:

1. metal- the most popular material from which plumbing and sewer pipes. It can be black, stainless and colored. These are compositions such as stainless and black steel, cast iron and copper. In addition, all steel pipes can be cold and hot rolled, welded and seamless - this determines the price and quality in terms of strength (how much pressure they can withstand).
2. Polyvinyl chloride (PVC)- this is water pipes HDPE for giving and country house which can be flexible or rigid. The flexible version is produced in a diameter of 32 mm and is used for ditching. That is, as an eyeliner from a centralized system or from submersible pump to the station and indoors. Rigid pvc pipes, used for sewage, can have a diameter of 32 mm or more, although more than 110 mm are not used in private estates - it simply does not make sense.

1. Polypropylene (PPR), k as a rule, it is used only for cold and hot water supply - the difference lies in the reinforcement. Pipe data, as well as instructions for use, will be given below - this is the most popular option.
2. Metalloplast - d about recently, these were also quite popular pipes for plumbing - they bend easily and are very easy to lay on the walls and on the floor in strobes. At the moment, their popularity has remained only for installing a system of underfloor heating - they are cheaper than cross-linked polyethylene, and for technical parameters superior to this material. I'll tell from personal experience- do not believe the advertisement - metal-plastic is much more convenient and more profitable to mount on a warm floor than polyethylene due to its reinforcement, which PE does not have.

Water pipes

On the street

Let's start from the street. You need to connect a submersible pump in a well or well - I will not focus on this, since this is a separate article, and we are talking about a pipeline. In this case country water supply from plastic pipes HDPE you need to lower into the trench.

There are certain parameters for this - see them in the table below. These, of course, are not all regions, but you can find out the parameters in your area in any architectural service.

City and surrounding areas	Depth in cm
Khanty-Mansiysk	240
Novosibirsk, Omsk	220
Ukhta, Tobolsk, Petropavlovsk	210
Orsk, Kurgan	200
Magnitogorsk, Chelyabinsk, Yekaterinburg, Perm	190
Orenburg, Ufa, Syktyvkar	180
Kazan, Kirov, Izhevsk	170
Samara, Ulyanovsk	160
Saratov, Penza, Nizhny Novgorod, Kostroma, Vologda	150
Tver, Moscow, Ryazan	140
St. Petersburg, Voronezh, Volgograd	120
Kursk, Smolensk, Pskov	110
Astrakhan, Belgorod	100
Rostov-on-Don	90
Stavropol	80
Kaliningrad	70
Khanty-Mansiysk	240
Novosibirsk, Omsk	220

Soil freezing table up to 0⁰C in different regions Russia

It is desirable that the pipeline laying is below the freezing point - then you do not have to do it. But, as you can see for yourself, in some regions the depth of zero temperature exceeds 2m and digging such trenches is not very convenient.

Therefore, you can use insulation. Personally, I prefer mineral (basalt) wool, which I then cover with roofing material for waterproofing - cotton wool is fixed with nylon thread, and roofing material with knitting or aluminum wire.

Laying depth and insulation are not all components of success. You will need a pillow that you can make from sand. At the bottom of the trench, pour sand 20-450 mm thick.

You put a pipe on it, which you again cover with sand by 50-60 mm from above. In order not to ram such a pillow (this is very inconvenient), you can pour plenty of water on it - the sand will sit down in a few minutes. After that, it will be possible to throw the excavated soil.

Now about the connections - a photo with docking diagrams can be seen a little higher. A piece of HDPE from the well to the foundation should be intact, but when entering the house (through the foundation), as well as on the passage through the well ring, compression fittings will be needed.

It is very simple to make a connection with their help, the main thing is to hold the pipe to a certain mark. For a well or well, you will need a 90⁰ fitting, and for entry through a foundation, you may need any angle. However, this is not the point - the main thing is to assemble it correctly.

In the house

Just in case, I leave the submersible pump connection diagram, although this is not quite on the topic (if you need details, see my other articles). I just want to emphasize that you make the input with the 32nd HDPE pipe, and leave the station with the 20th PPR pipe for wiring to authorities.

Here it is important to determine the installation location of the shut-off valves. It is advisable to install these taps near each bathroom so that you can turn off a separate point for repairs if necessary.

If you need heating of water pipes in the country (this is necessary with thin walls), then it is best to use polyethylene foam (nirelin) or mineral (basalt) wool for this. If the problem is serious, then you can use a heating cable that can be inserted inside the pipe or simply wrapped around it, and then covered with some other layer of thermal insulation.

The top photo shows the stages of polypropylene welding, and the image #4 shows a section. There, as you can see, there are no sags that could cut the passage hole. Look at the table below - it shows all the necessary welding parameters.

PPR welding mode table

PPR pipes are divided into RN-10, PN-20 and PN-25, where the number indicates the possible operating pressure. For example, a PN-20 pipe can withstand 2 MPa (20 kg / cm2) and is reinforced aluminum foil and it is most often perceived as universal. Therefore, I recommend using it for both cold and hot water.

Conclusion

Of course, such pipes for gas in the country are not suitable, but you can use them not only for hot water supply, but also for distributing heating in a system with radiators. you learned for yourself useful information? Share your thoughts in the comments.

July 25, 2016

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