Methods for connecting pipes during heating installation. What are the methods of connecting metal pipes? Benefits of Compression Fittings

To create a reliable heating system in the house that will work for many years, welding of heating pipes is used. The components of the systems, whether they are made of metal or plastic pipes, are connected in almost the same way. Existing differences in approaches to welding different types pipes are due to the difference in the design and operation of the units used. From what pipes were chosen for the installation of the heating system, its price will also depend. If you have already decided on them, we will show you how to connect the systems in a particular case.

What do you need for welding

To complete the welding process, 2 components are needed - equipment and skills:

Machines used for welding different design:

with electrodes for connecting metal pipes;
an apparatus resembling a soldering iron for joining plastic parts.

Requirements for professional skills:

electric welding of metal pipes requires experience with complex welding equipment;
even a non-professional can carry out the process of connecting polypropylene pipes through electric couplings with high quality.

Technology for connecting various types of heating pipes by welding

Connection of plastic pipes

Plastic (polypropylene) pipes, which are supposed to be used for heating an apartment, can be welded independently. For this, diffusion welding is used, which is a process of heating individual parts of the system with a special soldering iron to a certain state in which they can be connected.

Care must be taken to ensure that parts with the same properties are used for welding.

Before soldering heating pipes, it is worth rethinking the whole process to take into account the smallest nuances that can affect the quality of work:

Average heating time of pipes with a soldering iron: up to 5 s.
The temperature at which polypropylene is melted: 270°C. The required value for heating is set on a special temperature controller available on each device.
Depending on the time of year and the place of work, the process parameters may vary. AT winter period or when working outside a warm room, soldering plastic heating pipes requires slightly increasing the heating time or increasing the temperature to melt the polypropylene.
When connecting pipes of large diameter also increases total time needed to melt the material.
Docking time of heated parts for their soldering: 30 s or more (for large diameter pipes).
Soldering iron nozzles - for inner and outer diameters - simultaneously heat up the parts intended for connection (pipe and coupling).
During the heating process, "flanging" appears on the parts.
At the end of heating, the parts of the system are removed from the nozzles and immediately connected together, evenly pressing on them from both sides. It is impossible to rotate or somehow shift the heated parts after they are connected so that the connecting seam is not broken. Press them evenly against each other.
Withstand the connected parts for at least 30 s to ensure a strong bond. In this case, it is necessary to ensure that the side is uniform around the entire circumference of the junction.

The same instruction is also suitable for solving the question of how to cook large-diameter heating pipes. The whole difference lies in the fact that, as already mentioned, the time of heating and fixing the parts increases.

However, care must also be taken not to overheat them too much, since an excessive amount of molten polypropylene can narrow the working clearance of the pipes.

Watch the heating time of polypropylene parts. A change in their color to brown indicates that the material has overheated and is starting to burn.

Connection of metal pipes

Metal pipes in the water heating system are connected by electric welding. This method involves the use of metal electrodes that conduct electricity and play the role of an "additive" that fills the weld.

To obtain a high-quality weld, and, consequently, solid system pipes, it is necessary to observe the simple conditions that the welding of heating pipes by electric welding imposes:

In preparation for welding, all parts must be cleaned of dirt, sand and debris.
Straighten, if necessary, deformed pipe ends or cut them evenly.
When arc welding, the edges, inner and outer surfaces at the edge of the parts to be joined are cleaned to a width of up to 10 mm.
Welding of parts along the circumference is carried out in continuous mode.

Depending on the wall thickness, electric arc welding of heating pipes is carried out in several layers:

up to 6 mm: in two layers;
from 6 to 12 mm: in three layers;
over 12 mm: in four layers.

Each completed layer must be cleaned of slag before applying the next one.

As a rule, the first layer of welding is carried out by step welding. Subsequent layers are solid. When welding pipes, the stepwise surfacing is divided into sections, and the sections located through one are connected. Then the rest. The formation of the first layer should be treated with special responsibility. All edges of the pipes to be joined must be completely melted. If a marriage is found - the presence of cracks - you will have to cut down a low-quality section and carry out all the work again.

To overlay the first layer of the second and third layers, the pipes must be rotated very slowly and evenly. It is necessary to start each subsequent layer, moving a small (15-30 mm) distance from the beginning of the previous one. The seam, which is the finish, should smoothly pass into the base metal of the part and be smooth and even.

We hope that our instructions will be useful and help you quickly master necessary technologies installation of pipelines.

2003-11-19

SN and P 2.04.05-91*"Heating, ventilation and air conditioning" allow (p. 6) "pipelines of heating systems ... design from steel, copper, brass pipes, heat-resistant pipes from polymer materials(including metal-polymer) approved for use in construction. In a set with pipes, fittings and products corresponding to the type of pipes used should be used. At the same time, relatively steel pipes it is said (notes to Appendix 13): "the wall thickness of the pipe should be taken as the minimum according to GOST for the estimated diameter of the pipe, taking into account the connection on the thread or by welding," and also "electric-welded steel pipes should be connected by welding." As for plastic pipes, in addition to the instructions (clause 4 of Appendix 26): “the thread on the connecting parts must be full profile without torn and underformed threads and ensure screwing by at least one or two threads by hand "there are no other recommendations.

Regarding copper and brass pipes, no information is given at all. In this regard, an acute problem arises. It seems to us that it is dictated by the fact that the data given in the SNiP is not enough for high-quality and productive work on the installation, design and, of course, operation of heating systems. Indeed, today, in addition to threaded and welded joints, many other methods of assembling steel pipes are known. Plastic pipes made of PES - cross-linked polyethylene, PP-3 - polypropylene, X PVC - additionally chlorinated polyvinyl chloride and MP - metal polymer, approved for use (Appendix 25) for these purposes, differ from each other not only in a large spread of physical and mechanical parameters, but also ways of connecting. As for copper pipes, they also have their own connection specifics. In addition, if we take into account the fact that today these types of work are carried out by tens of thousands of organizations, numbering from a few people to hundreds or more workers and engineers, and sometimes there are no professionals among them - plumbers or heaters, the severity of the problem increases even more.

In this regard, consideration of the features of the connection of pipes allowed building codes and the Rules for use in water heating systems, should somehow reduce the severity of this problem.

To make it clearer distinctive features connecting all of the listed pipes to each other and with connecting parts, let's start with the steel pipe connections that have long been used in heating systems.

Steel pipe connection

Large construction organizations most often use welding (~2~) to assemble steel pipelines.

In this case, both gas welding and electric welding are used. These high-performance methods of connecting steel pipelines are very widely used in pipeline construction. However, they require highly qualified technical personnel performing installation work and special welding equipment, which in modern conditions conducting sanitary works is available only to large specialized organizations.

Therefore, small enterprises prefer to use for the same purposes standard fittings on short (~3~, a) and long (~3~, b) threads.

The main requirement for pipe thread is to ensure that the cut surface of the pipe is clean and free of burrs. When assembling pipes on a thread, it is necessary to ensure their alignment, as well as the strength and tightness of the joints. The tightness of threaded joints of steel pipes is achieved mainly by filling the gap between the internal and external threads with a sealing material along their entire length. The connecting parts or fittings must be screwed onto the pipe with some force, otherwise other connecting parts must be selected. If it is not possible to select the connecting parts, then you should replace the pipe or cut a fuller thread on it. Connecting parts or fittings must be screwed onto the pipe to failure, i.e. before jamming on the run. At the end of rolling, the threads should be cleaned, and the remains of the sealing strand should be removed from the surface of the pipe and connecting parts. The sealing materials used in the assembly of threaded connections must not be destroyed when fittings or fittings are screwed onto pipes, must harden in the gap between the threads without air access during operation, and must be plastic throughout the entire service life of the heating system. When using cone-to-cone connections (see ~ 3 ~, c), the threads are lubricated with mineral oil or oxol drying oil before connection, the use of an additional sealant is not required. Long-term practice has shown that as a sealing material for threaded connections of pipelines of heating systems at a coolant temperature of up to 100 ° C, it is good to use linen strand impregnated with red lead or whitewash mixed with natural drying oil. It is not allowed to use hemp and substitutes for natural drying oil. The use of flax as a sealant for threaded joints of another type (see ~ 3 ~, a and b) is explained by the fact that its fibers are long, thin and at the same time strong, therefore flax fits tightly in the thread recesses and does not collapse when screwing on the connecting parts or fittings. Recently, other sealing materials have appeared and are used (Table 1 ~5~). It is possible to effectively and reliably connect steel pipes by soldering, both simple and magnetic. The essence of the latter is that by pointing magnetic field it is possible to keep solid ferromagnetic particles in the gap between the pipes during the entire soldering cycle. When connecting pipelines to the socket by magnetic soldering, a magnet (~ 4 ~, a) is installed on the connected elements of the pipeline, which creates a magnetic field between the socket and the pipe inserted into it.

In this case, the magnetic field lines of the magnetic field are directed across the joint. This allows the gap between the pipes to be filled with iron powder. The magnetic field, holding the filler in the gap, forms a porous ring. When applied on top of the joint (with vertical arrangement pipelines) or next to it (with a horizontal arrangement of pipelines) and heating until the solder paste melts, it is possible, using capillary forces due to the small gap between the particles of iron powder, to keep the molten solder in the gap between the pipes. It impregnates the entire porous ring. And after cooling, it forms a strong brazed joint of steel pipes. A multi-flame annular burner is used to provide the necessary heating. It must move along the axis of the joined pipes. Special attention in this case, the heating of the inner pipe should be given. It can be controlled visually by the degree of luminescence of its surface. After the shrinkage of the solder begins, the burner is removed. As studies of the Research Institute of Mosstoroy show, the solder strength largely depends on the correct choice of the gap between the pipes to be soldered and the length of the solder joint (~4~, b). The use of magnetic soldering makes it possible to reduce the weight of the pipeline by tens of percent due to the use of thin-walled pipes.

Copper pipe connection

This seems to be one of the reasons why brazing is one of the main ways to connect copper pipes to each other and to the fittings. True, in this case, a permanent connection (~ 13 ~, a) of copper pipes is obtained by capillary soldering, which is normalized in the corresponding set of rules. Unfortunately, there are still no codes of practice that would regulate the connections of plastic pipelines in relation to heating systems in Russia. Therefore, the available literature data should be used.

Connection of polymer pipes

Pipes made of polypropylene are connected by socket welding, and pipes made of additionally chlorinated polyvinyl chloride are joined by gluing.

PP pipe connection

Socket welding is based on the conjugation of the melted surfaces of the parts to be welded by quickly pushing the end of one pipe into the socket of another (~6~).

For this, thin layers are simultaneously melted on the indicated surfaces with a heating tool: the inner surface of the socket is melted with a mandrel, and the outer surface with a sleeve. To create pressure on the mating surfaces of the pipes, the inner diameter of the sleeve is taken to be 0.2-0.7 mm larger than the outer diameter of the mandrel. The same ratio is recommended for the outer diameter of the pipe and the inner diameter of the socket (coupling). Therefore, in a cold state, the end of the pipe cannot be pushed into the socket of the fitting. When pushing the parts onto the heating tool, the excess material is removed by the edges of this tool. The removal of a small surface layer is a positive fact, since this reduces the risk of contaminants from the surface of the part entering the weld and destroys the oxidized surface layer of the part. When removing a layer of considerable thickness, the duration of heating of parts above the permissible limits increases, which can lead to the loss of their dimensional stability, as well as to the formation of beads of melted material inside the pipeline, which worsen its hydraulic characteristics. Welding is carried out at a temperature on the heating surfaces of approximately 270°C. In this case, the main welding parameters must be strictly observed (Table 2 ~9~).

Connection of pipes made of metal-polymer and cross-linked polyethylene

Metal-polymer pipes, like cross-linked polyethylene, are not welded or glued. However, this does not mean that they can be assembled using only one type of connection, as follows from the Code of Practice for the design and installation of heating systems from MPT. To connect pipes made of metal-polymer and cross-linked polyethylene to each other, with fittings, devices and pipes made of other materials, mechanical joints are used in the form of clamping couplings of various designs (they are manufactured and supplied to Russian market approximately 50 manufacturers, each of which produces them practically according to their own technology).

In Russia, there is no regulatory document on technical requirements for mechanical joints of plastic pipes. This circumstance imposes on the consumer a special responsibility for choosing connections from the whole variety of proposed designs.

A common element of all mechanical connections of these pipes is a fitting. A pipe is put on it, and the other end of the fitting is threaded for connection to a fitting, manifold or device. The outer surface of the fitting has annular protrusions - for connecting pipes made of cross-linked polyethylene, and for connecting metal-polymer pipes, annular grooves are also provided for laying sealing rings of a round cross section made of elastomers in them.

~7~ shows a PEX a XLPE pipe joint used by the Swedish company Wirsbo.

For the installation of this type of connection, a cutter (scissors) for cutting pipes, a tool for removing internal chamfers and burrs, pliers for expanding the clamp and wrenches for screwing a nut onto a bolt are used.

To connect pipes made of cross-linked polyethylene PEX a, the German company REHAU offers a one-piece connection, in which the pipe is crimped on the fitting by a tension brass sleeve (Fig. 7).

A pre-expanded pipe is put on a fitting with annular protrusions, after which, using a special device, the coupling is pushed all the way into the side of the fitting.

A similar slip-on coupling is used by the German company IVT to connect both XLPE and metal-polymer pipes. For metal-polymer pipes, a slip-on coupling with large inner and outer diameters is used.

In a one-piece connection of pipes made of cross-linked polyethylene by the Swedish company Wirsbo, of an identical design, a polyethylene heat-shrinkable sleeve is used instead of a brass compression sleeve. white color.

Many companies use a design with a steel compression sleeve for the permanent connection of metal-polymer pipes (Fig. 8).

An internal chamfer is removed from the end of the cut MPT, a gauge is inserted inside it to straighten the ovality formed during cutting. A fitting with rubber sealing rings put on it is inserted into the calibrated pipe. In order to avoid electrocorrosion, a dielectric gasket is installed at the point of contact between the end of the metal-polymer pipe (aluminum) and the metal connecting part. To compress a steel coupling, standard pressing tongs with a set of inserts with dimensions corresponding to the existing pipe diameters are used.

Various companies offer mechanical connections with union nuts (Fig. 9).

Connections (see Fig. 9, a-c) as an element that compresses the pipe have a split metal ring in their design, and in the connection (see Fig. 9, d) the compressing element is a continuous ring - a sleeve. Connections (Fig. 9, a and d) are manufactured by the Moscow enterprise ZAO Trubmetallokomplekt.

When using the connections discussed above, you should make sure that they are compatible, since for different manufacturers, the outer diameters and wall thicknesses of the pipes (even for the same nominal pressure) rarely coincide within the tolerances from the nominal dimensions. The paper also notes that there are many ways to connect heating pipelines. One of the highly reliable and progressive is the method of connecting metal-polymer, polymer, copper and stainless pipes using press fittings of two main types, differing in the type of pipes being connected. Metal pipes (copper and stainless steel) are connected using a fitting fitted on the pipe with an internal sealing ring. As a rule, this type of fitting is made of the same material as the pipe. Metal-polymer and polymer pipes are connected using structurally more complex fittings. Depending on the method of connecting metal-plastic pipes, the author divides all fittings into threaded (compression) and press fittings. When using threaded fittings, the pipe is fixed by squeezing it with a split ring and a tightening nut. When assembling the connection, wrenches, a pipe cutter, a pipe bender and a bevel calibrator are required. The disadvantages of threaded connections are possible mistakes during installation (insufficiently tightened thread) and more, compared to press fittings, the number of parts for assembling the pipeline. The installation of such fittings requires more time, as well as careful monitoring and maintenance during operation, since the tightening of the compression nuts weakens over time and depressurization of the connection may occur.

Press fittings for metal-plastic pipes usually consist of several parts: the fitting body itself with a fitting inserted into the pipe, having from 1 to 3 sealing rings, a compression sleeve and an insulating ring. The body of the fitting is made from heat-treated special brass with a low zinc content or from a special polymer, which guarantees high corrosion resistance and mechanical strength. The crimp sleeve is made of high alloy steel. Some fittings, such as Geberit Mepla, do not have a compression sleeve and the pipe itself performs its function. An insulating ring, usually made of Teflon, is installed between the body of the fitting and the end of the pipe and serves to galvanically isolate the pipe and fitting, which prevents the occurrence of thermoelectric corrosion.

What are the advantages of press connections over other connections?

Press connections are one-piece connections. This means that they do not need regular tightening and control during operation, unlike threaded fittings. Hidden laying, pouring into concrete is allowed. Permissible working pressure at the joints up to 1 MPa. Many manufacturers of press fittings give a guarantee on the connection up to 50 years. Fast and easy installation with a high degree of reliability without soldering, welding and threading. All this, according to the author, ultimately reduces the cost of the project and installation time, which is important for design and installation organizations, and high strength and reliability of connections significantly reduce operating costs and increase the service life of the system. Today there are more than a hundred manufacturers of press fittings and pipes, but this does not mean that there are as many press circuits. There is some unification, i.e. fittings of a number of manufacturers are crimped with the same contours.

The paper notes that TECEflex metal-polymer pipes are connected without any additional sealing. In a pipe-fitting connection, the seal is the pipe itself. As a result, the durability and reliability of the connection is in no way related to the characteristics of the seal material. Convenient and quick installation- this is one of the main advantages of TECEflex pipes. Used for installation hand tool which allows you to work even in hard-to-reach places. With the TECEflex tool there is no need for electricity or compressed air, as is often the case with many other systems. A special connection technique with axial sliding sleeves greatly simplifies the installation process. There is no need to cut threads, use welding or soldering. Each connection can be completed in less than 1 minute. It does not require any special skills. The connection design allows, after assembly and pressure testing, to lay the TECEflex system into a monolith, since, unlike most known pipe systems, TECEflex connections are guaranteed not to require maintenance (wrapping) during the entire service life. Thanks to the original connection technique using axial movable bushings, the nominal bore of the fitting is comparable to conditional passage pipes (the fitting is fully through). Thanks to this, the use of TECEflex greatly simplifies the work of planners and installers. This also significantly extends the service life of the TECEflex system, because it is precisely in the places where nominal diameters change that intensive wear of the inner surface of the pipe occurs. The minimum service life of the TECEflex system is 50 years. The TECEflex system uses universal fittings, a large selection of which makes work easier. Fittings are made of corrosion-resistant brass. The metal fittings of the TECEflex system can be reused many times. To do this, the connection must first be simply heated. building hair dryer after which it can be easily disassembled. To reduce the cost of construction, there are also plastic fittings made of PPSU. TECEflex fittings made of PPSU plastic have the same scope, thanks to the special qualities of the materials included in their composition. PPSU fittings are as durable as brass fittings. The difference is that they cannot be reused.

As noted in the work, metal-polymer pipes manufactured by REHAU are interconnected without the use of sealing rings made of elastomers using a fitting by radial crimping with a metal sleeve.

The paper describes connections for PEX-a pipes that can be used for 50 years at an operating temperature of 95°C and a pressure of 1 MPa. Wirsbo considers the simplicity of their installation to the undoubted advantages of these connections. Connections are made without gluing, welding, heating, soldering or threading. Ways of connecting pipes and fittings in Wirsbo systems can be described as mechanical with compression nuts (collet clamps) or with compression clamps (WIPEX connections) and self-crimping Wirsbo Quick&Easy. Wirsbo Quick&Easy couplings are designed for mounting Wirsbo-PEX and Wirsbo-evalPEX pipes with a diameter of 16-40 mm in manifold and tee systems radiator heating. The connection kit includes fittings made of high quality dezincification resistant brass and ferrules made of the same material as Wirsbo-PEX and Wirsbo-evalPEX pipes. In radiator heating systems, white rings are used for all pipes. The outer diameter of the fittings is greater than the inner diameter of the pipes, and the inner diameter of the rings is equal to the outer diameter of the pipes.

The Quick&Easy connection is made by flaring the pipe together with the ferrule put on its end using an expanding manual or hydraulic tool, inserting the fitting into the expanded pipe and then spontaneously crimping the ferrule around the pipe. This procedure takes no more than 15 seconds, during which a reliable, tight and durable connection is created with a service life equal to half a century. This technology is based on the fact that PEX-a polyethylene has molecular shape memory, high elasticity and the ability to return to its original state even after prolonged expansion. The Quick&Easy connection is one-piece, but unlike metal ring technologies, it can be easily dismantled. Undeniable dignity Quick&Easy connections is a smaller number of parts used in the connections. All of these factors, together with the speed, ease and simplicity of implementation, contribute to reducing labor costs, and, consequently, the total cost of work while increasing the reliability of the system. WIPEX connections are designed for the installation of central heating systems made of Wirsbo-PEX and Wirsbo-evalPEX pipes with a diameter of 32-110 mm. WIPEX connections consist of a crimp collar, a sealing ring with a round cross-section, a bolt, a washer and a nut. The selection of materials for joints, taking into account their industrial purpose, guarantees high mechanical strength and good anti-corrosion resistance. Thus, the inner surface of the fittings, which is in direct contact with water, is made of dezincification-resistant brass, and the outer surface is either made of acid-resistant stainless steel or bronze. Silicone rings are used to seal the mating parts of WIPEX. They are placed in a special groove made in the crimp clamp. The WIPEX design connection ensures a perfect pipe crimp and guarantees a reliable and durable connection. The breaking resistance of a WIPEX pipe connection is higher than the resistance of the pipe itself, and therefore temperature fluctuations do not affect its tightness. WIPEX couplings are strong and simple in design, they also allow you to work even in hard-to-reach places. Clamps are tightened with easy-to-use small ring wrenches or wrenches.

Wirsbo collets (clamps) are screw-in mechanical connections consisting of 3 elements: a sealing sleeve, a split sealing ring and a captive compression nut with internal thread made of dezincification resistant brass. They are used to connect pipes with a diameter of 16, 20 and 25 mm to collectors in radiator and floor heating systems. When selecting a connection kit with a compression nut, it should be taken into account that the split sealing ring and the nut for Wirsbo-PEX and Wirsbo-evalPEX pipes have the same dimensions, but the sealing sleeves are different. To avoid confusion on outside each sealing sleeve is marked with the size of the pipe for which it is used. In connections of this type with original Wirsbo elements, sealing takes place at the contact of metal surfaces (metal-to-metal) without the use of rubber gaskets. These connections will remain airtight regardless of temperature fluctuations and length of service.

X PVC pipe connection

According to work gluing X PVC pipes should include the following technological processes.

Pipe cutting: it is necessary to cut the pipe perpendicular to its axis, using special scissors or a hacksaw for this.
Pipe end processing: burrs are removed using a special scraper or a carpenter's knife.
Fitting of connected elements: to check whether the elements to be glued fit well, it is necessary to insert the end of one pipe into the socket of another pipe (sleeve) without glue (dry). The pipe should freely enter 2/3 of the depth of the socket, and then closely with resistance. (It is impossible to agree with such recommendations, since with a certain tightness it will not be possible to do this. In such cases, a measuring tool should be used.)
Surface preparation for the bonding process: for cleaning and pre-softening, it is necessary to clean the surfaces to be joined with a special solvent, using a clean rag.
Glue application: adhesive must be applied in an even layer outer surface end of one tube, using a special swab. The remaining amount of glue that remained on the swab should be evenly smeared on the inner surface of the socket on the other pipe (coupling).
Bonding process: after applying glue to both connected elements, it is necessary to immediately insert the pipe into the socket (coupling) until it stops, then, in order to obtain better contact surfaces, turn it 1/4 turn. The elements to be joined must be pressed and kept in this state for one minute (~12~). With proper bonding, an extruded thin bead of glue should appear around the joint.
Tests: after installation of the equipment, it is necessary to test the connections for tightness at a pressure 1.5 times higher than the operating pressure in the heating system, up to 0.9 MPa. The water pump should be installed at the lowest point in the system. It is necessary to remove air from the system. Then, filling the system with water, see if there are any leaks in it. At the first stage, the test should be carried out three times, increasing and decreasing the pressure from the minimum to the maximum test pressure. The test pressure in the system must not decrease by more than 0.6 bar (below 0.84 MPa) for each subsequent 10 minutes. If the system has passed the first tests, they should be repeated at a pressure p = 0.9 MPa. If during the 72 hours of testing the addition of water does not exceed 0.1%, we can assume that the heating system has successfully passed the tests.

Modern technologies for sealing pipes. Henkel LOCTITE. Pipeline systems. Plumbing, 2001, No. 1, p. 26.
Code of Practice for Design and Construction "Design and installation of pipelines internal systems water supply and heating of buildings from copper pipes” (in press).
Bukhin V.E., Romeiko V.S. Mechanical connections of plastic pipes. New technologies. Pipelines and ecology. No. 1, 2001, p. 25–29.
Romeiko V.S., Bukhin V.E., Ostavnov A.A., etc. Reference materials. Plastic pipes in construction. part 2. Construction of pipelines. Operation and repair of pipelines. M.: BAJIAHG, 1997. p. 188.
Set of rules for design and construction "Design and installation of pipelines for heating systems using metal-polymer pipes." SP, 41–98, p. 32.
Guo E. Modern technologies for the installation of metal-plastic pipes. Sanitary tool. "AVOK" PRESS. Plumbing, No. 1, 2003, p. 27–29.
TECEflex is a universal system of pipes and fittings for plumbing, heating and underfloor heating networks. Pipes and fittings. S.O.K., No. 7, 2003, p. 18–19.
New system RAUBASIC press pipework from REHAU. Pipelines. ABOK, No. 2, 2003, p. 38.
Connections for systems of water supply and heating of Wirsbo. Engineering systems. Plumbing. No. 6, 2002, p. 32–34.
Installation of polymer pipes. From the USMetrix pipe installation instructions. S.O.K., No. 7, 2003, p. 16–17.
Ostavnov A.A. Bonding pipes made of additionally chlorinated polyvinyl chloride. Connection of polymer pipelines. Plumbing. No. 2, 2003, p. 38–44.

Sometimes, when installing communication systems, it is necessary to combine elements made of different materials. Especially often in construction practice there is a connection of plastic pipes with metal, for which you can use different methods.

We will tell you how to connect the plastic section of the pipeline to an existing steel or cast iron system with maximum reliability. We have described in detail the technologies that make it possible to ensure tightness during docking. The article shows the fixtures and tools necessary for the job.

Usually, when laying plumbing, sewer or other systems, builders try to use the same material. However, in some cases it is impossible to do without combined structures. Most common causes are the following.

Planned replacement and urgent repair work . Pig-iron communications, which are equipped with houses built several decades ago, are gradually failing. With time metal elements become corroded or clogged, requiring them to be replaced routinely or in an emergency.

It is quite natural that in this case, old cast-iron or steel pipes are replaced with polymer pipes, which are less expensive and easier to install.

In old houses with long-established communications, modern polymer pipes are often connected to metal (usually cast iron) risers.

Construction. The process of individual or public construction of houses is associated with the laying of heating mains, sewerage, water supply. Often, different organizations are involved in the installation of various systems, due to the inconsistent work of which several types of pipes are supplied to the construction site - both from metal and from plastic.

Special cases. In some situations, the combination of dissimilar materials is an urgent need, for example:

pipeline connection to process equipment, high temperature which fusible plastic products cannot withstand;
laying the highway in areas subject to increased loads, for example, under busy roads or at the exit of a garage. In this case, on difficult areas more durable metal elements are laid, and on the rest - polymer ones.

As we can see, the need to combine different types pipes occur quite often.

Image gallery

If you need to choose a method for connecting pipes at home, then you need to decide on the material of the pipes and their purpose. That will depend on your choice.

Methods and types of pipe connection

The durability of the pipeline depends on how the pipes are interconnected, on their correct design and quality of parts. The main requirements for the connection are the preservation of strength when working under pressure, resistance to negative external influences and ease of installation.

Threaded pipe connection

One of the detachable methods is the connection of pipes using threads, which is used if pipes have to be disassembled. Detachable joints are not placed in places that are difficult to reach, otherwise it will be difficult to repair if a leak occurs. Advantages of the method:

suitable for pipe connection different diameter;
assembly can be done by a person without experience, professional skills and without special tools;
if seals are used, the thread will provide high tightness.

The only drawback of such a connection will be the difficulty of cutting the thread itself, for which special tools are used.

Threaded pipes are marked, if you look closely, you can see a fraction of two numbers, the numerator shows the inner diameter, and the denominator - outer dimension pipes.

Threaded connection methods

There are several ways to connect pipes using threads, but two are most in demand - squeegee and bidirectional thread.

The connection with the drive is used in cases where the pipes are motionless, they cannot be rotated around the axis. To do this, it is necessary that there are two pieces of pipe with different thread lengths. Prepare the coupling, locknut, any sealant. Coupling - connects two pipes, the lock nut holds the coupling, making it stationary, and the sealant prevents water from seeping between the threads. The connection is made as follows:

screw the locknut and sleeve onto the long thread;
bring a piece with a short thread and make the first turns with a coupling and a lock nut without sealing, in order to make it easier to find the end of the pipe to be connected;
tighten the locknut to the coupling at a distance of about 2-4 mm, the distance between them must be filled with a sealant;
the threads of flax or hemp are wound onto the thread from themselves, clockwise, and then a coupling and a lock nut are screwed onto them.

With this method of connection, the nut and coupling are, as it were, driven from a long thread to a short one, so it was called a drive.

Bidirectional threading involves the use of one coupling, which is wound simultaneously on two pipes at once. The pipes should have multidirectional threads so that the coupling pulls them together, as it were.

If one of the threads begins to let water through, then the coupling will have to be twisted from both pipes, and this is not very convenient.

Methods for sealing a threaded connection

One of the disadvantages of connecting pipes with a thread is insufficient sealing if special seals are not used, this is especially true for gas pipes or under high pressure. Now you can buy absolutely different sealants, for every taste and price - consider some of them.

What are threaded fittings

The most common threaded element for detachable connection of different pipes is a fitting with an internal and external thread. With their help, you can easily mount pipes or make their reconstruction, the main thing is that the joints are in easily accessible places. Minus - requires constant monitoring of their condition.

Materials used to make fittings: cast iron, brass, copper, bronze and stainless steel. In order to increase their anti-corrosion protection, these products are coated with zinc, nickel or chromium.

These connecting elements can be of different modifications:

couplings - used to connect straight pipes, have a thread located inside;
corner fittings are used to connect pipes going in different directions;
tees, crosses allow you to connect several pipes, can connect pipes of different materials and with different diameters;
plugs - in order to close the hole in the pipe.

Coupling with locknut

Coupling and locknut are used on pipes with short and long threads by the method of driving. In order for such a connection to be tight, the following rules must be observed:

use a seal: linen with drying oil, graphite putty;
make sure that the strands do not get inside the pipe, otherwise it may become clogged;
use a sliding key to jam the clutch on the run, this will not allow the clutch to move during use;
if it is not possible to advance the coupling to the end, then the structure should be disassembled, reducing the sealant layer, and assembled again;

Compliance with these rules does not guarantee that the connection will be tight, although a visual inspection of this place should sometimes be made to make sure that there is no leakage.

Detachable pipe connection without thread and without welding

There are many more ways to connect pipes without threads so that they can be separated later.

The choice of method will depend on which pipes need to be joined: they can be flexible - made of metal-plastic, polypropylene and polyethylene, and rigid - made of steel, cast iron and other non-ferrous metals.

With clutch

In order to connect two pipes, it is necessary to pass their ends through nuts, washers and gaskets and connect them inside the body. Now it remains only to screw the nuts. Gaskets are compressed and provide tightness, if this did not happen, then one more gasket ring should be added.

The most important thing is to choose a coupling of the required diameter. If you take a large coupling, then leaks cannot be eliminated.

Flange connection of steel pipes

Jointing with flanges is mainly used for steel pipes. A flange is a part for the repair and installation of individual parts of the pipeline. With this combination of pipes, several points are taken into account:

The nuts should not be skewed, so the sequence of their winding is as follows: first, they turn the nuts located one against the other, and not in a circle.
For plumbing, use a pad of rag cardboard soaked in drying oil.
For heating pipes need a gasket made of asbestos cardboard.
The ends of the bolts should not stick out of the nuts more than half.
The inner diameter of the gasket should be slightly larger than the diameter of the pipe, and the outer one should not touch the bolts.
Do not use several gaskets for one flange, this will reduce the tightness.

The flange connection is used for pipes of both small and large diameters. Can be used for gas pipes, chimneys, sewers and others.

Push-in pipe connection

For the installation of plastic pipes, collet fittings are used, which consist of a body where a compression ring and a rubber gasket are placed. Advantages:

low cost and availability;
reliability;
ease of installation;
the possibility of reusing the collet.

Please note that sometimes this fastening loosens, so it is necessary to tighten it from time to time.

Connecting pipes in this way is simple: first, a collet is inserted into the pipe, and then the outer nut is tightened. Do the same with the second pipe. It should be remembered that this detail has high pressure on the pipe, therefore, when tightening the nut, it is important not to twist it in order to prevent the appearance of cracks and cracks.

With clamps

Types of connections are different, one of them is a quick-detachable pipe joint. It is carried out using clamps - a device in the form of a metal ring with a tightening mechanism: nuts with metric threads. This method is designed to create a tightness of the hose, rubber pipes with a solid base. Installation is effortless.

Clamps can be different, for example, on sale you can find spring wire clamps that work on the principle of clothespins. Despite the simplicity of design, such devices can provide complete tightness of the connection.

Compression fittings

Compression fittings are used to connect plastic pipes. These parts allow you to make branches and turns, as well as increase the length of products. Advantages:

does not need constant monitoring, no need to periodically tighten the bolts;
can be laid in concrete or deep;
high degree of tightness, does not give in to corrosion;
easy and fast installation.

Types of permanent connection of pipelines

Sometimes there are situations when it is necessary to make a connection so that in the future it would be impossible to disassemble the entire structure. Such methods provide complete sealing of pipes and increase their strength, which is important for gas pipelines and heating systems.

Welding of metal pipes

Pipe welding is used mainly only for metal products. This method requires the involvement of specialists, since without skills and equipment it is impossible to make a high-quality welding seam.

Welding is carried out using gas, alternating and direct current, this requires welding units: automatic or semi-automatic.

There are two types of welding:

socket, when the outer end of one pipe is melted and inner part second bell, then these parts are connected;
butt welding melts both ends of the pipes and then they are simply connected, getting a weld.

Soldering of polymer pipes

Since the plastic has a low melting point, it is easy to connect them if you have a special soldering iron. It is enough just to melt the ends of the pipe, and then simply connect them. The pipe obtained in this way will not be inferior in strength to a solid one, since the material is connected at the molecular level.

This method is useful when a part of the pipe needs to be replaced. To do this, it is enough to cut out the damaged part, and solder it in its place. new plot without defects.

Butler Coated Socket Seal Joint

The connection of metal pipes with anti-corrosion coating using Butler equipment is used in the following industries: oil and gas, housing and communal services. But more often it is used for the construction of oil pipelines and the laying of pipes intended for the transportation of gas.

The meaning of the connection lies in the fact that the pipes prepared at the enterprise are connected by pressing one into the other. The main advantage is the possibility of installation in any climatic conditions.

Compression coupling and press fittings

A permanent connection can be made using compression fittings in the form of press couplings. Inside there is a belt made of durable polymers, reminiscent of rubber. To connect, it is necessary to prepare the end of the pipe, strip it and insert it into the compression sleeve. After that, with the help of pressing tongs, the pipe should be clamped in this coupling. This method is used when it is not possible to make a thread or apply welding.

vibration resistance;
durability;
withstand high pressure.

Tension fittings

If it is necessary to hide the connecting elements, then tension fittings can be used for this purpose. Installation starts without pre-training ends of the pipes, it is not necessary to carefully select the diameter of the pipe to the diameter of the connecting fitting. With the help of the pressure exerted by the sleeve located inside the pipe on its outer walls, absolute tightness is achieved.

First, a coupling is pulled over the junction, the ends of the pipe are expanded with the help of an expander, now it is necessary to place a fitting and a gasket inside. With a vice, the coupling is pulled to the place where the pipes were joined.

Push fittings (push fittings)

Such a fitting consists of an o-ring, a body, an outer casing and an inner ring. In order for the end of the pipe to easily enter the part, it is necessary to apply a little force, special devices are not required.

Such connectors are used in corners or in narrow spaces where it is inconvenient to make a connection in another way.

Connection of pipes of different diameters

To do this, you can use couplings, adapters, crosses and other connecting parts.

Plumbing can be joined using a coupling and a locknut if the pipe is straight and without corners. For a short connection, one sleeve is used, if a long one, a lock nut is added. The coupling must be marked with the diameters for which it is suitable. This method is applicable only for small pipes, for large diameters it is better to connect them by welding.

As you can see, there are many ways to connect pipes. It is possible to join pipes so that they cannot be disassembled in the future; such methods are used in hard-to-reach places to increase the strength and tightness of the connection.

Pipe connection: with clamps, without welding, with a coupling, with a thread, of different diameters

If you need to choose a method for connecting pipes at home, then you need to decide on the material of the pipes and their purpose. That will depend on your choice.

Ways to connect pipes without welding

Today, there are many more ways to connect pipes than traditional welding and threading. It depends on the material from which the connected products are made.

Metal (cast iron, steel, copper, stainless steel) and polymer (metal-plastic, polyvinyl chloride, polyethylene) require a different approach.

Methods for connecting flexible pipes

Fittings are used to connect flexible pipes without using a welding machine. They can also be connected by clutches that wrap around most connections. With the help of fittings, pipes are connected that have a diameter of up to 32 centimeters. However, it is considered impractical to assemble a large-diameter system in this way - the joint will have low reliability.

For joining polyethylene pipes of small diameter, compression fittings are used. This method is considered inexpensive and reliable. If the pipe has an average diameter, then it is better to use a coupling.

The device of the connecting node of the compression fitting

Rigid pipes

The main ways to connect rigid pipelines:

gluing;
use of clamps;
using connectors.

In plumbing systems, flanged connections are used.

Bell-shaped

The connection with sockets can be detachable and one-piece. This method is used for systems that are not subject to pressure. Examples are the joining of cast iron and plastic pipes in sewer systems:

You can use clamps. At the junction, the clamp is put on with a rubber lining.

To connect plastic or polypropylene pipes use glue. In this case, the system becomes inseparable.

In industry, pipes are connected in a nipple or hinge way. With the help of hinges, twists in the piping system can be avoided. To insert measuring instruments, a nipple connection is used.

Swivel connector for pipelines

Pressing and expanding

For the connection of copper pipes, pressing has proven itself. The work can be done quickly and easily. First, a so-called fitting is made using a pipe expander. The other end is inserted into it. The joint is clamped by a special pressing machine. Ready!

And also copper pipes can be flared. If necessary, this product can be disassembled.

There are many ways to connect pipes without the use of welding and threading. Each is great for a particular type of pipe. But they have their advantages and disadvantages.

The strongest connections are flanged.

Fittings are good because you can disassemble the system at any time.

Let's just notice! Threadless and non-welding methods cannot be used in the heating system.

Connection of pipes without welding and threads: from copper, metal, polyethylene

How to connect pipes from various materials if it is not possible to weld or thread them. Which methods are the most reliable, and which are only suitable for

Connecting water pipes of different diameters

For the organization of water supply, pipes with a diameter of ½ inch or ¾ inch are usually used. They are connected by means of an inch or metric thread, cut at the ends of products. The designation of the thread corresponds to the diameter of the product.

Different diameters - no problem!

What to do if you need to connect products with different diameters? The work is carried out according to the standard scheme, but there are nuances. In a specialized store, you must purchase fittings for pipes with different diameters. On sale there are tees, crosses, squares (or angles), adapters, couplings and other shaped parts designed specifically for products with different diameters. Which parts to purchase depends on the specifics of the upcoming installation of the water supply. As is obvious, you can connect two products with different diameters with your own hands, and several at once.

Water pipes are joined using a coupling, a coupling and a lock nut. These parts are screwed onto the threads of the products. At the end of one of the products, a thread of seven turns is cut. The work is done by means of a lerka fixed in a lerko holder equipped with two handles. For convenience, the product is clamped in a vice or in a special clamp. There are two possible ways to proceed.

We connect products with our own hands using a coupling

The method is suitable in cases where one of the water pipes is straight, has no corners or is short. For the procedure for connecting products, one coupling is required. Its thread designation must correspond to the diameter of the connected products. Consider the algorithm of actions:

On one of the ends of the product with a thread in an even layer, clockwise relative to the working end of the product, hemp ridges are wound in 5-6 turns. The hemp must be pre-straightened;
The product, with a hemp end, is immersed in a container with oil paint. The thread must be completely immersed in the coloring composition. Paint and hemp are needed to improve sealing, eliminate gaps. Then we take out the product, screw the coupling onto the working end with a pipe wrench, following the clockwise direction. We twist until it takes a lot of effort to continue working. Do not overdo it, otherwise the part may burst.

Tip: The end of the water pipe does not need to be immersed in paint. It is enough to lubricate it with an oil coloring composition using a conventional brush.

We connect products with our own hands without welding

This method is optimal in cases where the second water pipe has a sufficient length, angles, and parameters that are inconvenient for twisting. With one of the products, we repeat the algorithm described above (hemp, oil paint, and so on). Next, we proceed as follows:

On the second product, longer, an extended thread is made. Such that the coupling and nut enter the product completely, and a free edge of 2-3 mm remains.
The threaded ends of both products are joined, then the first product is twisted onto the water pipe with hemp until it stops. First, the lock nut is screwed on, and then the coupling;
The hemp is wound up, a coloring composition is applied to it, and only then the lock nut is screwed up until it comes close to the coupling. Hemp acts as a thin barrier between the locknut and the coupling. Pressed hemp provides better sealing of the plumbing system, prevents water from leaking during operation.

Tip: It is important not to overdo it when tightening the locknut if you have chosen a method of joining products without welding. Otherwise, it will burst within a short period of time. But even with its insufficient twisting, problems are possible. If you see water leaking between the sleeve and the locknut on a test run, carefully tighten the locknut tighter.

Conclusion

Without welding, it is recommended to install only water pipes with small and medium diameters used to organize water supply for domestic needs. If the diameter of the products is large, this method of connection is not rational, since it is quite expensive and less reliable at high loads. However, if you are installing plumbing in an apartment or a private house, these methods will suit you perfectly.

How to connect water pipes of different diameters: with a coupling without welding

It is possible to connect water pipes different diameter in many available ways.

Connection of metal pipes without welding and threads

The owners of not only private houses, but also apartments in modern high-rise buildings often faced with the need to connect metal pipes. To do this, you can use a variety of methods, materials and tools. The most widely used docking methods are threading and welding. But there are alternative options. After all, it is not always possible to conveniently get close to the problem area.

Any metal pipes can be connected without the use of welding machines and threading

Additional Arguments

rather high cost of welding. If only a few products need to be joined, it is not advisable to use professional welding equipment;
complexity of implementation. In fact, this factor applies to most construction works. It is no secret that they are often held in a cramped room with high humidity. In addition, there may be no power supply, the power of which will be sufficient for the functioning of the welding machine. In this case, without knowledge of how pipes are connected without welding, the performer will not be able to cope with the task;
lack of mobility. The occurrence of a situation of increased danger, for example, a breakthrough or an accident, requires the fastest and most effective response. It will take a lot of time to invite a specialist with his welding equipment. If the situation is really extreme, the most negative consequences can be expected.

Types of fittings

To connect metal pipes without threading them and without welding, parts called "fitting" are used. Their classification is based on two main criteria.

Press fittings come in different shapes and configurations, this allows you to mount a system with turns and branches

The first is the equal size of the diameters of the joined pipes. In accordance with this criterion, fittings are:

straight. They are used to connect products with the same section size;
transitional. Used in cases where pipes of different diameters are joined.

The second criterion is purpose. Fittings are divided into:

corners and bends. They are installed when it is necessary to change the direction of pipelines under different angles inclination;
tees. They are used to create branches from the main stream;
couplings. They are used to increase the length of a straight pipeline segment without threading and welding. This type is the simplest. However, it is the most sought after. The use of a coupling makes it easy to replace a piece of damaged pipe without having to replace the entire structure;
crosses. Such a connector provides the ability to divide the flow into several directions;
fittings. Provide connection of metal pipes with flexible bends;
adapters (futors, spurs, nipples). Such parts are used to connect different-sized pipes;
plugs, caps. Used to cover end holes.

According to the installation method, compression fittings are most widely used.

Important! Such fittings demonstrate high efficiency in the arrangement of street networks, as well as pipelines in apartments and private houses.

With the help of compression fittings, you can mount any system, including supply hot water and heating

Benefits of Compression Fittings

Compression fittings produced by modern industry for metal pipes are pressed and equipped with one or two ferrules. It is with their help that the connecting part is attached to the pipe. The rings are tightly pressed, so often when emergency press fittings will need to be cut and replaced with new ones. It would seem that not the best technical solution. However, most professionals who know how pipes are connected without welding and threading in other ways prefer press fittings. They explain their choice, first of all, by the fact that these parts can be installed in places where all other types of fittings simply cannot be mounted.

Among the advantages of crimp fittings, experts distinguish:

without welding and other additional work, absolute sealing of the working environment is achieved;
pipe connection is very reliable;
press fittings are characterized by a high rate of vibration fatigue.

Today, such parts are widely used in metrology, compressor and gas turbine equipment, for piping instrumentation and control devices, as well as in systems with a high level of working pressure.

Correct connection of pipes without welding and threads. Methods

The choice of method is determined by the type of products that are planned to be joined. Pipes are conditionally divided into the following categories:

The first type is cast-iron pipes, steel pipes, non-ferrous metal pipes or PVC pipes. The second type is products made of polyethylene, polypropylene and metal-plastic.

A reliable connection can only be obtained if the fittings are produced by a well-known company that guarantees quality.

1. To connect two metal pipes without threading and welding, couplers are commonly used. They are equipped with special fasteners and are characterized by high strength due to the fact that they are made of hard materials. But these properties are inherent only in the products of world leaders in this segment of the sanitary market - manufacturers from Switzerland, Sweden and France. Couplings are used for joining pipes made of different material or different diameters.

2. Another option for connecting pipes without welding and threading is the use of flanges. These parts are equipped with a rubber gasket. The sequence of work is as follows:

The attachment section is cut off. The cut is strictly perpendicular to the longitudinal axis of the pipe. It is not necessary to make a chamfer on the end.
A flange is put on the cut.
Then a rubber gasket is inserted so that it extends 8-10 centimeters beyond the edges of the cut.
After that, the dressed flange is connected to the counterpart, mounted in the same way on the second metal pipe.

Advice! Tighten bolts without excessive force. More than once there were facts that these fastening elements burst or fell off.

The answer to the question of how metal pipes are connected without welding using flanges will be incomplete without mentioning the following points:

It is not recommended to use multiple gaskets for one flange. This may cause a decrease in tightness;
in order to obtain a sealed joint, the nuts must be tightened not sequentially around the circumference, but in pairs located diametrically against each other;
for the water supply, a rag cardboard gasket impregnated with drying oil is used;
for heating pipes use a gasket made of asbestos cardboard;
bolts should not protrude from the nuts by more than half;
the outer diameter of the gasket should not touch the bolts, and the inner diameter should slightly exceed the diameter of the pipe itself.

The flange connection method is indispensable for large diameter pipes

Having learned how two pipes are connected without flange welding, you can properly equip the sewerage system and chimney, as well as the gas supply pipeline in a private house.

3. The connection with the Gebo coupling also found wide application. This part is one of the varieties of compression fitting. With its help, the joining of metal pipes is carried out quickly enough, and without the use of any special tools. The Gebo coupling components are installed on the pipe in the following sequence:

The nut is put on first.
Then rings: clamping, clamping, sealing.
Then the coupling is put on halfway, and the nut is tightened.
The second part is connected to the fitting in the same sequence.

4. It is possible to connect two pipes without threading and welding using a repair and assembly clip. This fitting looks like a coupling or tee, consisting of two parts. The halves are tightened with bolts.

It should be noted that the main purpose of repair and assembly clips is to perform temporary repairs, for example, when cracks appear. AT emergency cases, they can also be used for joining pipes. Installation is carried out as follows:

First of all, it is necessary to achieve absolute smoothness of the surface. To do this, the sections of the pipeline on which the fitting will be put on should be cleaned of irregularities formed by paint or rust;
then a rubber seal is put on the pipe. His cut is smeared silicone sealant.
then both halves of the fitting must be put on the rubber seal and tightened with bolts.

Advice! Check that the coverage of the pipe with the sealant is complete.

A pipe clamp is an easy way to temporarily connect two pipes without welding.

As we see, this way is also extremely simple. The same principle is embedded in the connection with a clamp. The only difference is that it is not tightened from two sides, but only from one side. However, the use of clamps provides a more reliable connection than a repair and installation clip.

Connection without thread and welding of shaped metal pipes

Most often, this procedure is performed using crab systems and clamps.

1. Crab systems. Such designs are connecting brackets with fasteners. Manufactured from 1.5 mm thick galvanized sheet metal. The brackets are assembled from two halves by means of bolts and nuts. AT assembled they form a "T" -, "X" - or "L" -shaped element that can tightly wrap around the ends of several (up to four) pipes. In terms of strength, such fasteners are comparable to a welded joint. The use of crab systems provides an opportunity to assemble and disassemble complex frame structures in a short time.

Of the disadvantages of this method, it is worth highlighting:

elements can only be joined at an angle of 90 degrees;
it is impossible to use crab systems for products with a large cross section.

2. Mounting clamps. Using these parts, you can create structures of any complexity, ranging from peaks and canopies, including racks and fences, and ending with greenhouses and animal enclosures. The main advantage of such fasteners is that the strength of the connection is close to welded, and assembly / disassembly of the structure is allowed repeatedly. Moreover, it can be done by a non-professional.

There are many methods for connecting metal pipes, alternative to threading and welding. Each is good in its own way. A choice should be made taking into account specific conditions. Some of them require skills and special equipment, while others can be implemented even by novice craftsmen.

Connection of pipes without welding and threads

Connection of pipes without welding and thread. Additional arguments. Types of fittings. Advantages of compression fittings. Correct connection of pipes without welding and threads. Methods. July 25, 2016
Specialization: facade finishing, interior decoration, construction of dachas, garages. The experience of an amateur gardener and horticulturist. He also has experience repairing cars and motorcycles. Hobbies: playing the guitar and much more, for which there is not enough time :)

The issue of connecting pipes without welding is always relevant, since not everyone has a welding machine home master and not everyone knows how to use it. At the same time, no pipeline is eternal, so such a need may arise in a country house, in a private house or in an apartment at any time. Below I will share with you some of the secrets of specialists that allow you to make such connections without welding.

metal

First of all, it should be said that all existing pipes can be divided into two types:

metal;
plastic.

As a rule, the most problems arise with the joining of metal pipes, so first we will consider the methods of their connection.

So, there are several options for hermetic docking:

Let's take a closer look at each of these options below.

With threaded socket

Most often, metal pipes without welding can be joined using a threaded connection. In this case, respectively, threading is required. It should be noted that this is not such a complicated procedure as it may seem to many at first glance.

To cut threads, you will need an electric thread cutter or dies for manual threading. Since the price of an electric tool is very high, below I will tell you how to do the job manually:

first of all, you need to clean the surface from the paint, which is to be threaded. If there are influxes of metal on it, for example, remaining after welding, they must be ground off;
then you need to remove the outer chamfer from the end with a file;
then, on the prepared end of the part, you need to put on a lerka (die) and make half a turn. In this case, it is necessary to ensure that the die is put on strictly perpendicular to the axis;
then you need to perform a quarter turn back;
according to this principle, the thread is cut to the required length. In the process of cutting, the cutters must be lubricated with a special liquid or any other lubricant;
then, according to the same scheme, threading is performed on another part of the pipeline to be connected.

For socket mounting on one pipe, the length of the thread must be several times longer than on the other, so that a socket with a nut can be screwed onto it.

After threading, you can make a coupling connection with your own hands, which is done as follows:

a nut is screwed onto a long thread and then a coupling;
a nut is screwed onto the second end of the part;
then the pipes are connected, and the coupling is rolled up with the length of the thread, as a result of which it begins to be wound onto the second part with a short thread. This procedure must be performed until the junction is approximately in the middle of the coupling;
then nuts are screwed on both sides. Before tightening them, a tow should be wound between the couplings and nuts to waterproof the joint.

This connection is reliable and durable. However, it is not always possible to cut threads. If, for example, the pipeline is located close to the wall, this operation is unlikely to succeed.

Connection with Gebo coupling

The Gebo coupling ("gebu" or "gebra") is a special compression fitting. With it, you can connect steel pipes without threading and welding very quickly, and this does not require any special tools.

The scheme of its use is extremely simple:

parts are put on the pipe in the following sequence:

screw;
clamping ring;
clamping ring;
sealing ring;
clutch;

then you need to put on the coupling halfway and tighten the nut;
then the second part is connected to the fitting in the same sequence.

I must say that this fitting exists both in the form of a coupling and in the form of a tee. This allows you to use it in cases where you need to perform a tie-in, for example, into a riser for wiring.

As for reliability, it depends on the quality of the installation. If the job is done correctly, then this montage is reliable and durable.

It is also possible to connect pipes without welding and threading using a repair and assembly clip. This fitting is a coupling or tee, which consists of two parts. Both halves are pulled together with bolts.

It should be noted that repair and assembly clips are intended primarily for temporary repairs, for example, in the event of cracks. However, in emergency situations, they can also be used to join pipes, especially if the pipeline does not work under high pressure.

In this case, the installation instructions are as follows:

first of all, the sections of the pipeline parts on which the fitting will be put on must be cleaned of rust and all kinds of irregularities so that their outer surface is absolutely smooth;

then a rubber seal must be put on the pipe. The cut of the seal must be smeared with silicone sealant. It should be noted that the seal must completely cover the pipes so that there is no gap left.
further, both halves of the fitting are put on a rubber seal and tightened with bolts, as shown in the diagram.

This method, as we see, is also extremely simple. By the same principle, a clamp-coupling is connected. The only difference is that it is tightened on one side, not two.

I must say that if you use pipe clamps, the connection of pipes without welding is even more reliable than using a mounting and repair coupling.

If you need to connect profile pipes without welding to assemble any structure, you can also use special profile clamps.

Plastic

If you need to assemble a plastic pipeline, you can use compression fittings, which work on the same principle as the Gebo coupling. Most often, metal-plastic and PVC pipes are connected in this way.

Also, sometimes special glue is used for these purposes. The installation process in this case is extremely simple:

places are smeared with special glue;
then the parts are rotated half a turn;
in this position they should be held until the glue hardens.

I must say that such a connection turns out to be quite strong, since the glue dissolves adjacent surfaces, and, in fact, welds them.

Compression fittings are also used to assemble metal-plastic pipelines. However, this requires a special tool that allows you to compress them.

For temporary repairs, the clamps described above can also be used.

Here, perhaps, are all the most effective ways pipe connections without welding, which I wanted to acquaint you with.

Conclusion

As we found out, in addition to welding, there are a number of other ways in which you can repair or even install a pipeline. Moreover, some of them allow you to get no less reliable and durable connection. The only thing, in any case, the work must be done very carefully, in accordance with the above recommendations, so that the pipeline is sealed.

For more information, see the video in this article. If you have any difficulties in the process of connecting pipes, ask questions in the comments, and I will definitely try to help you.

July 25, 2016

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