Hello dear visitors. A long time ago, in those days, when in Russia, the use of the CB radio band had just been allowed, a simple antenna was urgently needed. Naturally, the simplest and not requiring SU (matching devices) is GP. They had pipes from the old Wave Canal and a broken cot.

It was necessary to connect three tubes into a single whole, i.e. receive a 2.7m LENGTH PIN. The inner diameter of the tubes from the clamshell was 2mm larger than the outer diameter of the tubes from the old antenna. This is where the idea came up to use a split pipe, which could have an inner diameter greater than or less than the outer diameter of the connected pipes. In the first case, it is necessary to make a cut in the pipe of such a width that, when the pipe is compressed with clamps, it tightly compresses the connected pipe.

The tubes connected in this way have good electrical contact. The connection is solid. If necessary, the entire system is very quickly disassembled. I hope everything is clear from photos 1 and 2. Photo 1 shows just one of the GP antenna pipes, traces of old clamps are visible. In this way, you can also connect wooden parts.

Support for branches

Using such a connection (see photo 3), you can make collapsible, lightweight supports for branches fruit trees. The stores sell cuttings for rakes, which have a length of 1.2 ... 1.5 meters, a diameter of 3 to 4 cm.


Using a pair of these cuttings, a pair of worm-drive clamps, and a split aluminum tube of a suitable diameter, you can make an excellent backup. Another advantage of such a connection is the ability to tighten the clamps when, for example, the wood of the handle dries out. A couple of turns of the screwdriver - and the connection becomes rigid again. Sometimes the cuttings of shovels break, especially when they are made of birch, and there is no new one at hand, in this case, such a connection can also be used at the break point. It turns out a kind of bandage.

Grass scythe repair

For three years, the scythe at the spit broke in the place where the handle was embedded. Transplanting a scythe is a very serious and painstaking task. Again I remembered the split pipe. I thought temporarily, but it turned out like the Russians. The spigot broke in such a way that I had to shorten it, so instead of a split pipe, I used a pipe with cut ends. Here's what it looks like.

AT modern construction use a wide variety of pipes. There is also a large selection of ways to connect them into a single pipeline. Some require the use of special equipment and skills, while others can be handled by just about anyone. This article will discuss how to connect two pipes.

We connect metal pipes

Welding of metal pipes

To connect two metal pipes two methods can be used:

• welding;
• threaded connection.

The first option in recent times used less and less. The fact is that welding requires the use of special equipment - welding machine. Also, such work should be carried out by a specially trained specialist.

The connection itself can be made using various methods:

• transverse butt;
• longitudinal butt;
• one-sided corner;
• double-sided corner;
• socket overlap, etc.

Most of these terms are familiar only to specialists. Therefore, if a decision is made to connect the pipeline using electric welding, then it is better to call the master. The joints themselves are strong and reliable (subject to a well-done job).

Soldering copper pipes

If copper pipes are used, then the soldering method is used. Such pipelines are mainly used in elite buildings (copper is very expensive). Therefore, one cannot do without a highly qualified specialist, although if you read the article “Soldering copper pipes with your own hands”, you can try.

A more common method is a threaded connection. Anyone can assemble any pipeline using this method. Wherein assembled structure can be either straight, or with turns and bends. To do this, threads are cut at the ends of the pipes and a special lock nut is screwed on.

Threading a pipe by hand

The thread can be cut both at the factory and at home, because when installing pipelines it is often necessary to cut pipes, in which case you can do the cutting yourself. For this, it is most often used special device- klupp. This is a special, small tool made of high-strength material. By screwing this device onto a pipe, a thread is cut on it.

Klupp

The locknut is screwed onto the pipe joints. The result is a strong and reliable connection. Tow or fum tape wound around the thread is used as a sealing material.

You can also meet the connection without the use of nuts. In this case, fum or tow is wound on the thread and the pipes are screwed into the purchased coupling with an internal thread.

Scheme of pipeline installation on a threaded connection

Among the advantages of this method of connecting two pipes are its simplicity (all work is carried out without welding), reliability and collapsibility of the resulting joint. Namely, these properties are needed when creating intra-apartment pipelines.

Connection of pipes from other materials

soldering poly propylene pipes

The connection of two pipes made of HDPE and plastic can also be carried out using welding (in this case it is called soldering) and using fittings.

When soldering, two methods are used:

1. Butt.
2. With fittings.

The first option requires special equipment and can be performed by a highly qualified specialist. Butt soldering is used only when installing large-diameter pipelines, so it is not used when creating household communications. Soldering using connecting elements (electrowelded or special) can be carried out independently.

Compression fittings

But most often use connections without soldering. For this, special fittings are designed, such as:

• compression;
• reduction.

The first option is used when connecting pipes of the same diameter. In this case, the pipes themselves can be different materials.

Reducing fitting

Reducing fittings are used when it is necessary to connect pipelines with different diameters.

The principle of their use is quite simple. A fitting is put on each end of the pipe. Then, using wrench, the nut is tightened. The result is a strong and collapsible connection.

Press fitting for metal plastic pipes

Docking of metal-plastic pipes is carried out in two ways:

1. Compression fitting. During installation, the ends of the fitting are inserted into the pipe. They have rubber seals that securely hold them inside. Then the fitting is pulled together with a collet and fixed with a control nut. Such a connection can be subsequently disassembled.
2. Press fitting. This method is used less frequently, since the joint is one-piece. The fitting shanks are inserted into the pipe. Then, using a special device, the flexible cuff is crimped. The result is a strong and reliable connection.

Having familiarized yourself with the methods of connecting pipes, it remains to choose the product with which it will be most convenient for you to work.

Video

This video shows how to weld metal pipes with electric welding:

See how a plastic pipe is connected to an iron one:

kakpravilnosdelat.ru

It's simple - How to connect plastic and metal pipes without welding || STROIM-GRAMOTNO.RU

1. Pipe Fittings
2. Thread connection
3. Cutting
4. Difficult option

the entire plumbing system and only from the pipes, as you wanted it, everything will fail. heating radiators, heated towel rails are still made of metal. to prevent accidents of leaking joints, you need to know how to connect plastic metal welding pipes.

Fittings for PVC and pipes

Times, in stores desired element practically impossible, fortunately, for a long time Therefore, combining and plastic, the need to invent Everything has already been invented, produced, put up for you, you just have to go to pay for the purchase, it's too expensive for you) to bring home. the main thing is to buy what you need and a metal pipe.

By the way, fittings designed specifically for joints of metal plastic pipes, these are quality products that are capable of you enough on the condition that you can install correctly.

threaded

Since plastic and pipes without can be a few to start with the most popular ones.

So, you have a metal pipe, on your own thread for another. And for the question of how it is with a plastic thread that has it, you again need to buy it in the store. A fitting, you will purchase this, which is a coupling, with a threaded sleeve fused into one. Please note that the Americans are for different connected pipes.

In this metal plastic pipe connection as follows:

1. using a special soldering iron for pipes, weld onto the pipe. joint cooling.
2. metal pipe, it to the other and twist it with it. For sealing, you can use
3. Turn on the water to make sure it doesn't leak. turn off the leak again, unscrew the nut, repeat the procedure again with the old FUM tape.

Cutting

Threading dies

If there is no pipe on your pipe (this happens, you decide to use a new plastic pipe in your apartment or apartment), you will have to thread it first. Do this with a called threader. They can also be electric. you will be dependent only on its availability to you.

An electric threader is not out of the box. So if you need it for one or two times, then rent it from someone, don't buy it. True, it’s easier for them than with a lehr, so you don’t have to put any practical effort (for holding the pipe to its true if it comes out of you. The threader kit includes types of lerok for different pipes.

Pay attention If the distance of the pipe to is too small, you will just be able to put on the pipe. also fast enough and you take breaks from work, slicing into several

Regardless of which thread cutter you use, there are some that you need to get a neat result of the required length:

1. the beginning of the work must be cleaned available on the paint.
2. If the surface of the pipe is dripping metal, be sure to
3. When using manual, try not to do it first forward, then turn back, repeat everything until the thread is at your length.

option

clamping sleeve

The connection with the help guarantees a tight seal. However, there are times when, when considering, to connect the plastic metal welding pipes, refuse to go. Usually it happens because the metal is too long or located to and you can’t thread it.

This will have to use a difficult option, some consider it not reliable. In fact, this is so, and you are correct, then plastic and pipes will last long enough.

connecting the two you will need a Quick coupling (made in Poland):

1. clean metal pipe old paint.
2. disassemble the elements of the coupling in your hands.
3. Consistently on the metal part of the coupling. from the seal to the end must be less than 10
4. Gently insert the metal pipe into the connecting body, then slide all the rings and the nut into it.
5. So Coupling reverse side thread, then you can connect the metal with the American, to the pipe

By choosing this connection, not that Quick couplings are produced different diameters And if you have a coupling on the pipe, then most likely you did not buy what you

Well, to check how much you have tightened on the pipe, pull holding the second pipe so as not to pull out of the wall, it should not be along the pipe.

records

stroim-gramotno.ru

How to connect two pipes of the same diameter: actual ways of self-implementation

In this article, we will consider what is the instruction for connecting one-dimensional pipes made of various materials. The topic of the article is interesting, since the market offers a wide range of different pipes, which differ from each other not only in operational and technical specifications, but also by different methods of connection into a single system.

But, before considering the specifics of the installation work, consider what types of plumbing accessories can be purchased.

In the figure, a threaded connection of heating pipes made by means of a coupling

Classification

Collapsible connection profile pipes bolts in the construction of the greenhouse

All water pipes, in accordance with the production materials used in their manufacture, are divided into the following categories:

• metal modifications;
• polymer modifications;
• plastic products.

Important: Each of these modifications is represented on the market by a wide range of products that are characterized by one or another connection method. Therefore, when planning the installation of plumbing in your apartment or country house, it is necessary to take the choice of materials and methods of connection with the utmost responsibility, since the price, durability and appearance finished system.

So, let's look at how the mixer is connected to the pipe on its own.

Docking of metal pipes

Threaded connection on a steel water pipe

During the installation of metal (cast iron, steel and copper) plumbing and heating systems threaded and welded joints are used.

Let's look at each of these methods in detail:

1. Threaded installation, by the way, also includes the connection of pipes by an American, this is a technology that allows you to assemble water pipes from elements with the same cross-sectional diameters.

To do this, a thread is cut at the ends of both pipes, over which a special metal coupling is screwed - a fitting. By means of special fittings it is possible to assemble both straight and curved plumbing and heating systems.

The fitting used on such structures has internal thread, while the pipes are threaded externally. If the fittings for installation are purchased with already threaded threads, then on the joined elements it will have to be cut with your own hands using dies.

Among the advantages of the technology, we note the strength and durability of the finished result. In addition, if necessary, the threaded fitting can be untwisted and the entire structure can be disassembled in order to fix the breakdown or redo it.

Important: As a rule, standard threads are used on pipes and fittings. But if foreign-made accessories are purchased from little-known brands, you need to make sure that the product will match the metric thread type.

1. Mounting plumbing systems using welding is used infrequently. The main disadvantage of a welded joint is the inability to make it yourself, since a professional welder with special equipment and experience in using this equipment can cope with such work.

For the installation of two one-dimensional pipes, the following types of welded joints are used:

• transverse butt (without boring or with internal boring) with backing ring;
• longitudinal butt (without a bevel or with a bevel) with a one-sided seam;
• transverse butt with one-sided seam;
• one-sided corner;
• double-sided corner;
• bell-shaped overlap.

The butt joint is the most common, as the finished result is characterized by high strength, provided that the joined elements are correctly centered.

If a water pipe with an internal diameter of up to 500 mm is assembled, a one-sided seam is welded, the strength of which is quite sufficient. If the diameter is larger, the root of the seam is welded from the inside, as a result of which the strength of the joint increases.

A welded seam is considered the optimal type of connection for the installation of industrial water pipes, but is rarely used in everyday life due to the high cost. finished version and cramped conditions for the use of the welding machine.

Soldering copper components is a technology used in the assembly of premium plumbing systems.

The installation principle is as follows:

• the ends of the joined elements are cleaned and covered with solder;
• the inner surface of the fitting is cleaned and covered with solder;
• the pipe is inserted into the fitting and heated with a burner;
• after the solder has cooled, a strong and durable coupling joint is obtained.

Types of connection of polymer products

In the diagram, a phased connection corrugated pipes

If the question is how to connect HDPE pipes, then in this case, installation is an order of magnitude easier than assembling a metal water pipe. No threads are cut on plastic, and installation is carried out in two ways: by soldering or using fittings.

1. The connection of HDPE pipes using fittings is popular in the assembly of domestic water pipes and sewer systems. The relevance of the method is not surprising, since fittings, regardless of modification, can be installed even by a novice plumber.

Fittings, according to structural features are divided into the following categories:

• Crimp modifications are simple yet effective and versatile mounting accessories. For installation, special pliers are used to evenly distribute the applied force around the entire perimeter of the crimp collar.
• Press fittings are the most reliable, as they guarantee the complete absence of leaks.

Connection picture PVC pipes using compression fittings

To learn how to connect metal pipes without welding, you need to study in detail the methods for connecting these pipe materials. The point is that pipelines are complex design from the serial connection of the pipe assortment, measuring equipment, which are provided for in the project.

Matching can be done various methods. When choosing optimal solution focus on the purpose of the highway and the conditions for its use. Also take into account the diameter of the pipe assortment.

When laying the highway, the connection method may be different. Some of them may be one-piece, but dismantling with subsequent reassembly of the structure is possible.

And there are monolithic joints that cannot be disassembled without destroying the structure. Welding has won the greatest popularity among monolithic joints. But, this is far from the only method that allows you to connect sections of the pipeline, there are others.

Despite the high popularity of plastic, steel products are still used. Welded fastening is used very often, but such a joint is impossible without special knowledge and skills. Therefore, many try to use options that allow you to connect in a different way.

Mounting with threaded connection

How to connect iron pipes without welding will be discussed further, but in this article you can find out. To make docking, this method is very common.

The threaded connection can be located in such places of the main line, where the conditions allow for constant control of the joint. Moreover, it should be possible to repair work if necessary.

Most often, threads are rolled on special equipment, but such work can be done independently.

It is performed in the following sequence:

How to connect without threading and welding

Next, you can learn how to connect metal pipes without welding and threading. Speaking of connecting metal pipes, this method cannot be bypassed, because it is very popular during installation work.

Installation work is carried out in the following sequence:

1. Metal pipes prepared for fastening are cut off at the end parts. The cut on them should be done perpendicularly and make sure that it runs smoothly.
2. A coupling is applied to the connection area. The center of the connecting element must be located exactly in the pipe joint area.
3. Markings are made on the pipes with a marker, it will indicate the position of the fitting.
4. Silicone grease covers the end parts of the connection.
5. AT connecting piece according to the mark indicator, one pipe is inserted. After that, the second is put in the same axial line with the first, and only after that it is attached with a coupling. When dressing, the mark affixed with a marker will be a guideline.

Watch the video

Metal gas connection

• The correctness of the connection is checked as follows. A soapy solution is applied to the joint area. When they appear on the surface soap bubbles, the joint is advised to stretch harder.

Docking silencer pipes without welding

If a common problem has come with a rotten muffler flange, then you should think about how to connect the muffler pipes without welding. The whole point is this. In this situation, there are several options.

The first option is to cook. The next option is to buy a new muffler. The third option is to look for alternative exits. In both cases, you have to pay big money. If there is no strong rust on the muffler, then you can use a clamp.

As practice has shown, such clamps have long been used by world-famous car companies such as Volkswagen and Audi. And it should be noted that these devices in many cases have successfully replaced welding in car repairs.

To connect pipes at an angle and for a branch, other types of fittings are installed: elbows, transitional and others. The end parts of the parts for the joint must be cleaned, and the thread must be made with a high degree of accuracy.

To increase the strength of the joint of these products, it is wound with a strand of flax, only the thread is covered with white before that.

The short threaded part is characterized by such features. In the area of ​​the two turns at the end, which are called thread runouts, the depth is usually shorter. This makes it possible to provide a more durable joint without welding, without using runaways and seals.

Two parts on the elongated threaded part can be fastened together without welding by means of a drive. On the first part of it is a short thread, and on the other - a large one. The short one is designed for fastening with a coupling. A coupling with a lock nut is put on an elongated thread. A large thread allows you to adjust the length of the workpiece.

Drives are most often used in the repair of a section of the highway that has become unusable. The docking element and the locknut are driven onto a large thread.

To mount the squeegee, a sealing thread is used. It is screwed to the end of a short threaded thread on a metal product.

Sometimes, when installing the drive, a bundle of FUM tape is laid between the locknut and the coupling. It is laid in three layers. Such a joint is performed as follows:

1. A coupling and a lock nut are screwed onto a large threaded thread.
2. At the same time, they also take a sealing thread. It is wound on the end of the coupling, which is tightly fitted with a lock nut.
3. The tourniquet must lie in a chamfer, only in this way neither liquid nor steam can leak out.

Speaking about how to connect two metal pipes without welding, it is worth dwelling separately on such an option as Gebo. In parts of the highway where the connection is in a hard-to-reach area, this method turns out to be quite effective.

The name Gebo was given to a special fitting. It is put with the sole purpose of connecting several pipes. All work can be done quickly and easily. Thread cutting is not required.

There is an erroneous opinion that it is dangerous to join a riser with such a part without welding. But, properly mounted, this element can withstand very heavy loads. It should also be added here that such a mechanism is highly resistant to the influence of axial forces.

While maintaining standards temperature regime such a detail perfectly holds not only hardware but also plastic.

Using the material outlined above it is clear how to join metal pipes without welding. Almost all of the proposed methods are suitable for inexperienced craftsmen, and allow you to connect products without expensive welding work that require high qualifications and special equipment.

Soldering aluminum at home, technologies, methods

1. The simplest and in a reliable way, connect something or attach to aluminum or its alloys - this, of course, is a bolt and nut or rivet. All other methods require some training, fixtures, special solders, aluminum soldering fluxes, etc.

As practice shows, aluminum is not soldered at all in the usual way, with tin-lead solder, the reason for this is an oxide film, which forms almost instantly after cleaning the surface to be soldered.

2. Therefore, one of the ways to solder aluminum is - coating the surface, immediately after stripping, with a layer of molten rosin. Not the best, but after repeated attempts, rubbing the soldering point with a soldering iron tip, you can achieve satisfactory results.

3. Further, a solution of rosin in diethyl ether can be used to solder aluminum. We clean the surface and immediately lubricate it with such a flux, and then sprinkle it with copper filings, which serve as an abrasive to remove the oxide film, and tin the place of soldering with ordinary solder (tin-lead). After, solder to the tinned area copper wire or something else.

4. The next aluminum soldering technology is the use of special solder for aluminum soldering and flux. Most of these solders are low-temperature, but their melting point is higher than that of tin-lead, within 300-600 g. C. The key to success is also a good warm-up and for this they use gas burner or blowtorch.

High-temperature solders are used for soldering massive parts, they are used to repair and restore parts made of aluminum and its alloys of any complexity (cars, motorcycles, etc.). The soldering is very strong. In this way, tubes are soldered, for example, aluminum and copper, inserting one into the other and soldering around. But, when soldering aluminum with other metals, make sure that the solder and flux are designed for one and the other metal.

The surface is cleaned and covered with a special flux, as in previous cases, and when the solder melts, you can scrape the place of the solder with the tip of a stainless steel knife (or stainless steel brush) to better remove oxide film. Thus, we tin the aluminum surface and solder everything we need to it.

This does not end the ways of soldering aluminum at home. You can apply the electrochemical method.

5. We clean the surface and apply a few drops of CONCENTRATED solution of copper sulphate to the place of soldering. Then, we take a power supply for 5-12V and a current of about 1 ampere (or more), we connect a resistance of 4-5 ohms and powerful to the power supply. 5-10 W, and our device is ready. We calculate the load in such a way that the PSU does not burn out during operation, i.e., approximately at a current of 1-5 Amperes.

Now we connect the aluminum blank to the negative pole of the power supply, and to the positive we attach a bare copper wire (you can twist it into a small flat spiral), which is then introduced into a drop of vitriol solution so that the end does not touch the surface of the part. Everything is ready, turn on the power supply and wait a few minutes. A layer of copper, as a result of electrolysis, will settle on the place for soldering. And then, wash off (but do not try to erase the copper), tin, and solder the wires or terminal. This method, of course, is not suitable for soldering some massive parts, but it is suitable for contact with wires.

6. Alternatively, instead of a solution of vitriol, you can use hydrochloric acid: drop it into the place of soldering and then drive the copper drive along the contact pad. Copper precipitation occurs faster than in the first case, but one must be careful with acid. And be sure to thoroughly rinse the place of soldering with water.

Connecting copper pipes: instructions and comparison of various installation technologies

So that the acid does not corrode the excess area, it can be sealed with tape or filled with paraffin, and the desired area should be exposed. That. you can solder aluminum with copper and other metals, and the contact pads will have a beautiful, neat shape.

That's all, and if there are any other ways to solder aluminum or additions to the above, write.

Viktor Donskoy
www.masteru.org.ua

17330 0 7

Size matters: how to connect two pipes of the same diameter

In this article I want to talk about ways to connect pipes, first of all - sealed, used in the installation of water supply and sewerage. The material is of an overview nature and is intended only to acquaint the reader with a variety of mounting methods: I deliberately will not mention the subtleties of technology and recommend this or that tool. So, let's go.

Steel

Despite the abundance polymer pipes, black and galvanized steel is still in demand in the housing and utilities sector and in the installation of highways high pressure. Applied methods of connecting elements steel pipelines largely dependent on the cross section of the pipe.

Electric welding

Diameters: any, pipe wall thickness: from 0.5 mm.

When welding with high currents, it is easy to burn through the walls of a thin-walled pipe; a decrease in current leads to sticking of the electrode. Therefore, electric welding of thin metal requires a certain skill.

Dignity: arc welding- the only way to connect pipes of large diameter with a significant wall thickness, providing acceptable seam strength. Automated welding is used in the production of seam pipes and in the installation of pipelines.

Disadvantage: A sealed seam is almost impossible for a beginner. Welding pipelines requires the highest qualifications.

Technology:

As usual, there are a number of nuances:

• The chamfer can be removed only from the outside of the pipe or from the outside and from the inside. Thick-walled pipes of large diameters are welded on both sides;
• When welding pipes of small diameters, the lashes must first be grabbed at two or three points and aligned along a common axis, then proceed to weld welding around the entire circumference. Due to uneven heating, the seam area leads noticeably;
• Welding can be performed with a continuous supply of argon to the area of ​​the arc. Inert gas completely eliminates the oxidation of the seam.

Minor leaks on cold water lines can be eliminated by rubbing a hot seam with a piece of bitumen. Due to the capillary effect, it instantly fills the pores with the melt. On the hot water this instruction is useless: when heated again, the bitumen will melt again and be forced out of the pores.

Gas welding

Diameters: up to 100 - 150 mm.

Pipe wall thickness: up to 3-4 mm.

Advantage: undemanding to the experience of the welder. I got a sealed seam after a few hours of practice.

Disadvantage: the inability to cook thick-walled pipes with gas. The burner is simply unable to heat their walls until the edges are melted.

Technology:

1. The pipe is cut perpendicular to the longitudinal axis;
2. From thick-walled pipes (more than 2 mm), the outer chamfer is removed;
3. The edges of the future seam are heated with an acetylene torch to a bright red glow and fusing edges;
4. A welding wire is introduced into the torch of the burner, the melt of which fills the seam. The melt bath must not solidify: only in this case the seam will be airtight.

A special case

Fixed sutures are welded with a mirror or with the help of a surgical suture. In the latter case, a window is cut in the pipe, then the seam is welded from the inside, after which the window is welded again.

Coupling

Diameters: up to 50 mm.

Wall thickness: any.

Advantage: the simplest threaded connection of pipes that can be connected in series and rotate around the longitudinal axis.

Disadvantage: coupling assembly of a long whip eliminates disassembly separate connection. Pipes have to be unscrewed from the couplings sequentially.

Technology:

1. Pipes face at right angles to the longitudinal axis;
2. On the lathe or with your own hands, using a die, a short (five thread) thread is cut on both connected pipes;
3. A threaded pipe is screwed onto one of the pipes, into which the second pipe is screwed. For sealing, sanitary flax is used (preferably impregnated with paint or sealant) or polymer sealing thread.

Couplings, in particular, were installed in houses with steel water supply lines and served to connect them to eccentrics when installing a wall-mounted mixer.

Sgon

Diameters: up to 50 mm.

Wall thickness: any.

Advantage: makes the connection of fixed pipes collapsible.

Flaw: the long thread of the drive is the most vulnerable to corrosion thanks to minimum thickness walls and lack of protective paintwork. It, being applied, is violated at the first disassembly.

Technology:

1. A short thread (5 threads) is cut on one pipe, a long thread (12-15 threads) is cut on the other;
2. A lock nut and a coupling are successively screwed onto a long thread;
3. The coupling is driven all the way to the wound short thread;
4. Following it, a lock nut is driven, clamping the winding of the thread in front of the coupling.

flanges

Diameter: 76 mm or more.

Wall thickness: from 3 mm.

Advantages:

• The connection remains collapsible, including on fixed lashes;
• The force required for mounting or dismounting is not tied to the diameter of the pipe. With an increase in diameter, the number of bolts tightening the flanges increases;
• Flanges can be used to connect to shut-off valves or to install retaining washers. In particular, it is the washers that circulate in the hot water risers of most houses built in the 80s and newer.

Disadvantages: the flange is mounted only by electric welding, which is not always convenient in the field.

Technology:

1. Pipes face perpendicular to the longitudinal axis;
2. External (and with a large diameter - internal) chamfers are removed from them;
3. Flanges are welded;
4. After cooling and cleaning the seam, the flanges are pulled together through a rubber, silicone or paronite gasket. The bolts are tightened alternately, crosswise, one turn at a time. The price of breaking this simple rule is uneven compression of the gasket and a high probability of leaks during pressure surges.

Compression fittings

Diameters: up to 32 mm.

Wall thickness: any.

Advantages: extremely simple installation with the help of hand tool, the possibility of installation on pipes affected by corrosion.

Disadvantage: low tensile strength of the connection.

Technology:

1. The edges of the pipes are cleaned from paint and rust;
2. They are then inserted into the fitting with the nuts loosened;
3. Nuts are tightened. At the same time, they compress the pipe with rubber o-rings, sealing the connection.

A special case

Compression fittings are also used for the installation of corrugated stainless steel pipes. However, in this case, the strength of the connection is not inferior to the strength of the pipe itself: it can withstand pressure up to 50-65 atmospheres. The secret is simple: the silicone sealant of the fitting compresses not a smooth surface, but a corrugation crest, so it is almost impossible to pull it out of a tightened fitting.

Many fittings use an additional locking of the comb with a split retaining ring.

American

Diameter: up to 32 mm.

These are the sizes of American women I saw on sale. Perhaps they are also produced for diameters of 40 - 50 mm, but I have not seen such offers in the assortment of local construction and online stores.

Wall thickness: any.

Advantages: extremely fast disassembly of the connection. To open the pipeline, it is enough to unscrew union nut.

Disadvantage: American pipe connection requires pre-threading.

Technology: the halves of the dismantled American fitting are wound onto the wound threads of adjacent pipes, after which they are pulled together with a union nut. Tightness is ensured by an annular rubber gasket.

Crabs

The so-called crabs are steel plates that allow you to bolt round and shaped pipes. They are used in the assembly of greenhouse frames, racks (trade, for tools, etc.) and other structures that do not require special strength or tightness of joints.

Pipe sizes: diameter up to 25 mm; sections of profile pipes up to 20x40 and 25x25.

Wall thickness: any.

Advantages: allow quick assembly and disassembly with a pair of open-end or box wrenches; allow multiple reuse fasteners and pipes.

Disadvantage: limited durability.

Technology: the ends of the pipe are clamped between the halves of the "crab", after which they are pulled together with bolts and nuts.

Collected on the "crabs" greenhouse.

PVC

PVC pipes are known, first of all, as the most affordable solution for indoor and outdoor installation. However, pressure socket pipes are also used for the installation of water pipes.

O-rings

The connection of PVC pipes with the help of ring seals is practiced both in free-flow sewage and in pressure pipelines. Only the thickness of the pipe walls and the force required to undock the socket differ.

Diameters: 50 - 600 mm.

Wall thickness: any.

Advantages: pipes are delivered completely ready for installation of the connection, with ring seals installed. When cutting to size for installation, couplings with two opposite sockets are used.

Disadvantages: a lot of effort required to assemble the joint with a large pipe diameter; the possibility of spontaneous disconnection of the connection.

Technology:

1. The factory ends of the pipes are ready for joining. On pipes cut to size, burrs are cleaned and the outer chamfer is removed;
2. A small amount is applied to the end of the pipe and the O-ring liquid soap or silicone grease;
3. The pipe is pressed into the socket.

With a significant effort required for pressing, the following can be used:

• Clamp and lever systems;
• Loading equipment.

Adhesive connections

They are used in the installation of pressure pipelines. The glue is a solution of polyvinyl chloride in an organic solvent.

Diameter: up to 110 mm.

Wall thickness: any.

Dignity: the connection is almost as strong as a solid section.

Disadvantage: the connection is made non-separable.

How to connect PVC pipes with glue?

1. Glue is applied to the inside of the socket and to the end of the pipe with the outer chamfer removed;
2. A smooth section of the pipe is inserted into the socket and rotates 90 degrees;
3. The connection is fixed until the glue sets (no more than 1 minute).

Polypropylene

The only mass-used method of connecting propylene pipes is socket welding. For this purpose, a monolithic polypropylene sleeve is used.

Diameters: 20-110 mm.

Wall thickness: any.

Advantage: the connection is as strong as a solid pipe.

Cons: required special tool(low temperature soldering iron); the connection is non-separable and can only be cut out.

Technology:

1. The pipe is cut with a pipe cutter or a regular hacksaw;
2. The outer chamfer is removed;

Aluminium-reinforced PN25 pipe requires stripping of aluminum foil in the welding area. For this purpose, a hand-held shaver or a drill attachment similar in functionality is used.

1. The pipe is inserted into a soldering iron nozzle of the appropriate diameter heated to 240 degrees. At the same time, the second side of the nozzle is used to melt the sleeve;

1. The fitting and the pipe are combined with a smooth translational movement and are fixed until the polymer melt sets. The time of fixing, heating and cooling is predictably determined by the section of the pipe. For the convenience of the reader, I will collect all the recommended parameters in one table.

Diameter	Heat	Fixation	Complete cooling
20 mm	7 sec	6 sec	2 minutes
25 mm	8 sec	10 sec	2 minutes
32 mm	8 sec	10 sec	4 min
40 mm	12 sec	20 sec	4 min
50 mm	18 sec	20 sec	4 min
63 mm	24 sec	30 sec	6 min
75 mm	30 sec	30 sec	6 min
90 mm	40 sec	40 sec	6 min
110 mm	50 sec	50 sec	8 min

Polyethylene

Polyethylene pipes are used:

• For laying pressure sewerage;
• As a material for cold water mains;
• When organizing country water pipelines;
• When installing a non-pressure sewer.

When installing a polyethylene sewer, the connection of HDPE pipes is no different from that for socketed PVC pipes with ring seals.

Black sewage pipe- polyethylene.

For pressure water pipelines, two fundamentally used different ways installation.

Butt welding

Diameter: from 40 to 2400 mm.

Wall thickness: from 4 to 70 mm.

Advantage: the strength of the seam reaches 80% of the strength of a monolithic pipe.

Disadvantage: when joining pipelines of large diameters, expensive equipment and mechanical or hydraulic devices for centering and clamping are required.

The clamping force of the pipe during butt welding should reach 1.5 kgf / cm. In this case, the cross-sectional area of ​​\u200b\u200bthe cut of the pipe can be calculated in thousands of square centimeters.

Technology:

1. The pipe ends only at a right angle to the longitudinal axis;
2. Welded ends are centered;
3. A heater mirror is inserted between them;
4. After melting, the mirror is removed, and the ends of the pipes are pressed against each other;
5. After complete cooling of the joint, the burr (extruded polymer melt) is mechanically cleaned for inside pipes.

Compression fittings

How to connect HDPE pipes with a small diameter and insignificant wall thickness?

In this case, the compression fittings already familiar to us are used.

Diameter: 16 - 32 mm.

Wall thickness: any.

Advantages: easy installation without the use of tools, quick disassembly.

Disadvantage: relatively low tensile strength.

Technology:

1. A union nut, a retaining ring and a rubber or polyethylene seal are successively put on the pipe;
2. Its end is inserted into the fitting;
3. The nut is tightened, compressing the pipe with a sealant.

metal-plastic

Metal-plastic is two layers of cross-linked (reinforced by cross-links between polymer molecules) polyethylene with a thin aluminum tube between them. During installation, three connection methods are used.

Compression fittings

Diameters: any.

Wall thickness: any.

Advantage: the use of the simplest hand tools. I usually use for fitting assembly a pair of spanners.

Disadvantage: the quality of the connection depends on right technology assemblies. If the pipe is not sized, the rubber o-rings will dislodge over the fitting and leak after several heating and cooling cycles.

Technology:

1. We cut the pipe with pipe cutter scissors;
2. Calibrate it and remove the internal chamfer;
3. We put a union nut and a split ring on the pipe;
4. Apply silicone grease to the fitting fitting;
5. Careful not to dislodge O-rings, put the pipe on the fitting;
6. Until it stops, we shift the split ring and nut to the fitting;

1. Tighten the nut until you feel resistance.

Press fittings

Their only difference from the previous solution is that instead of a union nut and a split ring, the pipe is crimped on the fitting with a stainless steel sleeve.

Diameter: any.

Wall thickness: any.

Advantage: a properly made connection does not leak at any temperature fluctuations.

I suspect that press fittings do not flow just because when installing them, professionals are not too lazy to calibrate pipes and chamfer. According to my observations, a connection assembled according to all the rules on compression fittings does not concede to a press fitting reliability.

In the photo - a plastic tee with two push couplings and an adapter for pipe threads.

Diameter: any.

Wall thickness: any.

Dignity: simple assembly without the use of a tool.

Disadvantages: high cost of fittings, moderate tensile strength of the connection.

Technology: the end of the pipe is inserted into the fitting with a previously loosened nut, after which it is tightened. The pipe is fixed with a metal ring with paws directed inward. Tightness is ensured by an annular rubber seal.