How to weld polypropylene pipes: soldering process in detail. Welding temperature of modern polypropylene pipes What is required for installation work

Such a technology for installing pipelines for various purposes, such as welding polypropylene pipes, has become a real find for many amateur craftsmen.

Polypropylene pipes are used in the construction of plumbing, heating and sewer communications.

Having chosen this method, the devices of water supply, heating and sewer communications ceased to be dependent on the services of welders, who were quite expensive.

Advantages and disadvantages of PP

Polypropylene pipes have a number of advantages, including:

• long service life;
• no corrosion;
• small mass;
• ease of installation, which can be handled by a person who does not have the qualifications of an electric gas welder.

The disadvantages of PP pipes include:

• lower, in comparison with steel pipelines, strength;
• high coefficient of thermal expansion;
• destruction of the material under the influence of ultraviolet radiation.

For pipelines with cold water, the issue of thermal expansion is not as relevant as for pipes for hot water supply and heating systems, however, with the start of production of PP products reinforced with foil or fiberglass, the problem of sagging of heated conduits can be considered closed. As for strength, it is better to place plastic pipes under the cladding. In the same way, they should be protected from sunlight.

If you decide, after weighing all the advantages and disadvantages of polypropylene pipes, to build a pipeline out of them with your own hands, then recommendations on how plastic pipes should be welded will surely come in handy.

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What pipes to use

It should immediately be said about the most popular in the device pipeline systems of pipes made of polypropylene. Among them:

• pipes with a cross section of 32 mm (they are used in risers and supply pipelines);
• products with a diameter of 25 mm (used for the installation of risers, floor wiring, installation of heating systems)
• pipes with a diameter of 20 mm (connection of water supply and heating system).

It should be recalled that reinforced pipes should be used for transporting hot water, whose coefficient of thermal expansion is 0.03, and for cold water, cheaper products without a reinforcing layer can be used (their expansion coefficient is 0.15).

Nevertheless, the change in the linear dimensions of the pipeline, even reinforced with aluminum foil or fiberglass in a section 5 m long, can be 15 mm (what can we say about non-reinforced pipes, the length of which, when heated to 90 ° C, increases by 1.5 cm per linear meter) .

This factor should be taken into account when designing a heating or plumbing system. To avoid stresses in the pipeline, on its straight sections with a length of more than 5 m, it is necessary to install not rigid, but only fasteners supporting the pipe. In addition, compensators should be mounted on such runs. They can be made U-shaped or in the form of a loop.

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Types of welding of PP pipes

Scheme of welding PP-pipes "butt".

Additional turns of the line will require the use of fittings, and welding of plastic pipes will help to connect them and pipes into a single system. There are 2 types.

1. Fitting welding.

As for the latter, it is used when assembling pipelines with a diameter of 50 mm or more and a pipe wall thickness of 4 mm or more. This method will be discussed later. It should be noted that at home, the installation of such a pipeline is rarely carried out, since it requires rather expensive specialized equipment. This technology is mainly used for the construction of main water pipelines, including sewage.

Fitting welding has become more widespread, which is easy to do with your own hands by buying or borrowing for a while a device for soldering polypropylene pipes.

This welding machine (in other words, an iron or a soldering iron) does an excellent job of connecting pipelines of the most popular diameters in the construction of individual water supply and heating systems.

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Fitting welding technology

Fittings are required for welding polypropylene pipes.

The technology for welding PP pipes is based on the physical properties of polypropylene, which melts when heated to 175°C, but is able to restore its strength when cooled, which occurs in a matter of minutes.

During welding, both the end part of the tube and the fitting are heated and melted. When docked in a hot state, they are soldered together and, when cooled, turn into an almost monolithic connection.

Welding of the pipeline is carried out with a special soldering iron, but you still need to use:

• marking tool;
• hacksaw for metal;
• construction knife.

However, with the help of a hacksaw and a knife, it is difficult, although possible, to achieve high-quality processing of the end edges of the tubes, therefore it is better to use a pipe cutter for cutting, as well as a shaver, which cleans the internal cavities of the tubes with reinforcement before welding.

Since the tubes are driven into fittings during welding, then, when calculating the length of the pipeline system, it should be taken into account that each tube will be buried in them by 14-22 mm (depending on the diameter of the pipes and fittings) from each end. When calculating the total length of the pipeline, you need to add the result of the calculation (for example, 15 mm x 2K, where K is the number of welded joints).

The "iron" is equipped with special nozzles, in which pipes and fittings of corresponding diameters are simultaneously heated. The heating temperature is 260°C. As soon as the polypropylene becomes sufficiently plastic, the elements of the pipeline are connected and held for some time with some effort. During fixation of the assembled parts, loads that deviate away from the axis of the assembly are not allowed.

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Errors when welding conduits

In addition to various distortions that will lead to insufficient tightness of the seams, the home master can make a few more mistakes when assembling the conduit.

1. Dirty or wet pipes are mounted: dirt will cause lack of fusion, and water evaporating when heated will deform the connection or form “shells” in it. To avoid such troubles, the tubes should additionally be cleaned immediately before welding.
2. The cavity of the reinforced PP tube to be heated is poorly cleaned of aluminum foil: it is necessary to check the quality of the cleaning of the walls.
3. Polypropylene remains on the nozzles of the soldering iron after welding the previous section - in this case, the remaining plastic must be removed, but only wooden tools or a rag can be used to remove it so as not to damage the Teflon layer. Cleaning of nozzles should be carried out on a slightly warm instrument.
4. Using low-quality material for welding - you should buy PP pipes only from bona fide sellers. Unreasonably cheap products should be suspicious.
5. The reason for poor-quality welding is the use of pipes made by different companies. They may have different chemical compositions, so their heating and cooling times, as well as their degree of softening and diffusibility, may vary. For each circuit, it is better to purchase products from the same manufacturer. It is advisable to purchase all elements of the conduit in one batch.
6. Poor-quality installation of the pipeline - it has already been written about distortions, but the tightness of the joints is detrimental to:

• insufficient penetration of the workpiece into the fitting;
• weak heating of the elements (there will be no reliable soldering) or delay in connecting the pipes, which will lead to the plastic solidifying even before they are assembled;
• overheating, due to which slush can form, impairing the permeability of the collector;

In order for the welding of plastic pipes to be of high quality, you should use the data in the following table.

It can be seen from it that it is necessary to connect the heated PP tubes as quickly as possible, and they should be pressed against each other for the time specified in the "Welding Time" section. In addition, home craftsmen who decide to assemble the pipeline on their own can be advised to weld the line even before it is assembled on site, where it will be inconvenient to do so. Therefore, a detailed diagram is needed indicating the exact dimensions of all sections of the pipeline and its configuration.

The ability to assemble pipelines on your own is a definite plus of polypropylene products. Using a convenient and lightweight material, you can build a sewer with your own hands, repair and modernize the water supply system.

The main thing is to understand the specifics of connecting prefabricated elements to each other. Agree, this is an important part of the work, responsible for the tightness of the line and its trouble-free operation.

We offer you detailed information on how polypropylene pipes are soldered, what equipment is used in the work, and we also list the most common mistakes novice welders make.

The information we offer will help to build trouble-free communications. For visual perception, the article is supplemented with graphic applications and a video guide.

The soldering process is carried out due to the pronounced thermoplastic properties of the material. Polypropylene softens when heated - it acquires a state similar to plasticine.

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This is what a soldering iron ("iron") for polypropylene pipes looks like. A simple electrical device, semi-automatic, thanks to which plastic is soldered

For butt welding, the designs of soldering irons are characterized by increased complexity. Usually, such equipment includes not only a heating element, but also a system for centering the parts to be welded.

As a rule, direct welding equipment, like the technology itself, is rarely used in the domestic sector. The priority of use is industry.

A more complex device, which is used to accurately center the parts to be welded with a further heating and soldering process. Used with direct welding technology

In addition to soldering irons, the master will also need:

• scissors - ;
• roulette construction;
• locksmith's square;
• shaver for pipes with reinforcement;
• marker or pencil;
• surface degreaser.

Since the work is carried out on high-temperature equipment, be sure to wear thick work gloves.

Polypropylene Welding Procedure

Important warning! Welding of polymeric materials should be carried out in conditions of good ventilation of the room. During heating and melting of polymers, toxic substances are released, which in a certain concentration have a serious impact on human health.

The procedure for welding polypropylene is simple, but requires accuracy and accuracy in work. Common mistakes should also be avoided, such as insufficient or excessive heating.

First of all, you need to prepare for work:

1. Install blanks of the required diameter on the heater plateau.
2. Set the regulator to 260ºС.
3. Prepare mating parts - mark, chamfer, degrease.
4. Turn on the soldering station.
5. Wait for the operating temperature to set - the green indicator turns on.

The mating parts (pipe - coupling) should be simultaneously placed on the blanks of the soldering station. In this case, the polypropylene pipe is mounted in the inner region of one blank, and the coupling (or socket of the fitting) on ​​the outer surface of the other blank.

Usually, the ends of the pipe are inserted along the border of the previously marked line, and the coupling is pushed all the way. When holding polypropylene parts on heated blanks, one should remember an important nuance of the technology - the exposure time.

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Conclusions and useful video on the topic

Professionals always have something to learn. How to work with polypropylene can be seen in the following video:

Mounting pipelines made of polymers by soldering them “hot” is a convenient and popular technique. It is successfully used in the conditions of installation of communications, including at the household level.

People without experience can use this welding method. The main thing is to correctly understand the technology and ensure its exact execution. And technological equipment can be bought or rented.

Do you have experience in soldering polypropylene pipes? Please share information with our readers. You can leave comments and ask questions on the topic in the form below.

In modern construction, almost 70% of pipes are made of polypropylene. They are used not only in the laying of new pipelines, but also in the repair of old systems. When installing the system, the technological rules of welding must be observed, and in order to achieve the best results, all the nuances must be taken into account, which include the welding temperature of polypropylene pipes.

Properties of polypropylene pipes

This type of pipe is currently the most common, as it combines excellent technical qualities and low price. Polypropylene pipes are strong, durable and can resist corrosive damage.

Possessing such qualities, polypropylene products can be used in various fields:

• when laying water and gas pipelines;
• for drainage outlets;
• for removal and transportation of various aggressive liquids.

The following kit is required for welding polypropylene pipes:

• thermometer;
• scissors designed for cutting pipes;
• degreaser;
• old rags made from natural fibers;
• tape measure, marker;
• scraper;
• a special device for welding polypropylene elements with a diameter of more than 50 mm.

Also, when working, you may need improvised tools: a knife, a hacksaw, if it is not possible to work with a pipe cutter or scissors.

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Preparation of the device and material for welding polypropylene pipes

Before you start welding polypropylene pipes, it is important to properly prepare the equipment.

First of all, the heating nozzles must be firmly fixed to the welding device. Using a thermostat, set the temperature to 250-270 degrees and connect the device to the power supply. The required time for heating the appliance is set according to the room temperature. To prevent damage to the working layer of the nozzles, they must be cleaned with a rag before heating.

Welding can be started if the required temperature is shown on the indicator or contact thermometer.

Before starting welding of polypropylene pipes, it is necessary to conduct a visual inspection, since the surface layer of the elements must not have any defects, the fittings must be in working order. All threads must be checked with products with opposite threads.

Pipes and fittings to be welded must be thoroughly cleaned and degreased. All fittings must be checked for consistency. Fittings that wobble and fit poorly are discarded.

All pipes must be carefully measured and cut. If they were cut off with a hacksaw, then the edges should also be deburred.

Using equipment designed for this purpose or a sharp knife, the pipes are cut at the end of the welded edge to about 45 degrees. These manipulations are mainly performed with large-sized products (section more than 40 mm). This cut is required to avoid delamination of the material when the pipe end is inserted into the fitting.

Before starting the soldering of volumetric elements, it is necessary to check their circumference.

Before you start soldering pipes, it is important to remove the oxidized layer from them along the entire halo of the joint, since the oxide negatively affects the quality of the welds.

It is important to insert the pipe into the fitting before soldering and make marks for the depth of its entry, but taking into account the fact that the pipe is inserted all the way. To avoid narrowing of the pipe in the seam, you need to leave a gap of 1 mm.

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Heating temperature of the welder

Compared with butt welding, where the parts are heated at a surface and low temperature for a long time to avoid stress inside the material, in propylene socket welding, the temperature of the apparatus is increased and it heats up faster. The choice of heating temperature of the welded device is subject to several restrictions:

1. Melting of welded surfaces must be carried out quickly, pipes may lose their original appearance, and it will be difficult to combine them. This is the reason for the high heating temperature of the device.
2. If the welded device is overheated, then the polypropylene elements may undergo thermal deformation.
3. The Teflon coating that covers the working part of the apparatus remains in excellent condition if it is constantly operated at a temperature of 260 degrees, but if higher temperatures are used, the device gradually fails.

Considering all the nuances of socket welding, the optimal temperature for heating the working surface of the nozzles was set at 260 degrees, with deviations of plus/minus 10 degrees.

Such a heating regime can adversely affect the internal stress at the joints. But this is compensated by the almost double wall of the pipeline system at the joints and the maximum welding area.

Many models of devices for socket welding of polypropylene pipes are equipped with a temperature setting regulator. The thermostat is designed in such a way that when the appropriate temperature is set, it corresponds to the temperature on the welded nozzles. The heater temperature is 15 degrees higher.

Most models of welded devices are outdated and do not have a regulator knob, and their temperature regime is set by the manufacturer immediately to 260 degrees. Given the working technology, according to the masters, this is correct, since the regulator knob is most likely installed to increase popularity.

Any modern housing, be it a private mansion or a city apartment, is necessarily equipped with a variety of engineering communications. And if so, then either during the construction process, or during repairs or reconstruction, sooner or later the owners will have to face the problem of installing or replacing pipes - and heating systems. Few people are now attracted by the laborious and rather complicated installation of VGP steel pipes. They are expensive in themselves, require considerable additional costs for transportation, and their processing and connection are associated with specific operations that not everyone can do - cutting, bending, electric or gas welding, threading, etc. Plus, a special approach is required for the “packing” of each threaded connection in order for the connecting assembly to turn out to be of high quality, without leaks.

It's good that modern technologies make it possible to do without all this trouble by using polypropylene pipes. With the right choice of material and high-quality installation, plumbing and heating circuits practically do not retreat from steel in any way, in many respects they are far superior to them. In addition, the soldering of polypropylene pipes itself is not so complicated, the instructions for which will be discussed in this publication.

Not all polypropylene pipes are the same

Before starting to consider the installation instructions for polypropylene pipes, it makes sense to give at least a general idea about this material, in particular, about its varieties and applications. The choice of pipes according to the principles “which is cheaper” or “what were” is completely unacceptable. The consequences for an indiscriminate home master can be very sad - from the deformation of the laid pipeline to its rupture or the appearance of leaks in the connecting nodes.

There is no need to explain the difference in diameter - in different systems and in their various sections, their sizes are used, which are predetermined by hydraulic calculations. The range of diameters, from 16 to 110 mm, allows you to almost completely provide all possible options. Moreover, practice shows that for a house or apartment, an assortment of up to 40 mm is usually enough, much less often - up to 50 ÷ 63 mm. Pipes of a larger diameter are, rather, main ones, and they have specific installation features, but it is unlikely that a home master will have to deal with it.

The difference in color between some types of pipes may immediately catch your eye. This is the least you can pay attention to - white, green, grayish and other walls - do not say anything. Apparently, this is just a decision of manufacturers to somehow distinguish their products from the general background. By the way, for heating circuits, white color will definitely be preferable, since the pipeline will unobtrusively fit into any interior without creating a disharmonious color “spot”.

But the colored bars, if they exist, already carry an informative load, intuitively understandable to everyone. The blue stripe - the pipe is designed exclusively for cold water supply, the red one - is able to withstand elevated temperatures. However, such a color marking (which, by the way, very often does not exist at all) is only very approximate, not fully revealing the operational capabilities of a particular pipe. It helps not to make a mistake during the installation of the system. By the way, the longitudinal line is also good because it becomes a good guide when joining mating parts during soldering.

Much more information is given by alphanumeric marking, which is usually applied on the outer wall. This is where you should be more careful.

The international abbreviation for polypropylene is PPR. There are several varieties of material, and you can find the designations PPRC, PP-N, PP-B, PP-3 and others. But in order not to completely confuse the consumer, there is a clearer gradation of pipes - by type, depending on the allowable pressure of the pumped liquid and its temperature. There are four such types in total: PN-10, PN-16, PN-20, PN-25. In order not to talk for a long time about each of them, you can give a plate that characterizes the operational capabilities and scope of pipes.

polypropylene pipes

Of course, in order for the pipe to withstand elevated pressures and temperatures, it must have thicker walls. The value of the wall thickness and, accordingly, the nominal diameter of polypropylene pipes of various types are in the table below:

With all the advantages of polypropylene, it also has a rather significant drawback - a very significant linear expansion when heated. If for cold pipelines located inside the building, this is not so significant, then for hot water pipes or for heating circuits, this feature can lead to sagging, sagging of long sections, deformation of complex interchanges, and the appearance of internal stresses in the body of the pipe, reducing its service life.

To minimize the effect of thermal expansion, pipe reinforcement is used. It can be aluminum or fiberglass.

The fiberglass reinforcing belt is always located approximately in the center of the pipe wall thickness, and does not affect the soldering technology in any way.

But with aluminum - a little more complicated. There are two types of such reinforcement. In one case, the foil layer is located in close proximity to the outer wall of the pipe (bottom left in the illustration). Another option - the reinforcing belt runs approximately in the center of the wall. For each type of such reinforcement, there are special technological nuances of installation, which will be discussed below.

Both fiberglass and aluminum reinforcement significantly reduces the thermal linear expansion of polypropylene pipes. In addition, the aluminum layer also performs another function: it becomes a barrier against oxygen diffusion - the penetration of oxygen molecules from the air through the pipe walls into the coolant.

The penetration of oxygen into the liquid medium of the coolant can cause a number of negative consequences, among which the main ones are increased gas formation and activation of corrosion processes, which is especially dangerous for metal parts of boiler equipment. The reinforcing layer is able to repeatedly reduce this effect, therefore, such pipes are most often used specifically for heating circuits. In plumbing systems, it is quite possible to get by with fiberglass reinforcement, which does not have a significant effect on diffusion.

The illustration below shows an example of marking a polypropylene pipe:

1 - in the first place is usually the name of the manufacturer, the name of the pipe model or its article.

2 - material of manufacture and structure of the pipe. In this case, it is a single-layer polypropylene. Pipes with fiberglass reinforcement are usually marked PPR-FG-PPR, with aluminum - PPR-AL-PPR.

There may be reinforced pipes with an outer polypropylene layer and an inner wall made of cross-linked polyethylene. They will have a designation such as PPR-AL-PEX or PPR-AL-PERT. This does not affect the soldering technology, since the inner layer does not participate in it.

3 is the standard pipe dimension coefficient, equal to the ratio of the outer diameter to the wall thickness.

4 - nominal values ​​of the outer diameter and wall thickness.

5 - the type of pipe mentioned above according to the nominal working pressure.

6 - a list of international standards to which the product complies.

Pipes are usually sold in standard lengths of 4 or 2 meters. Most retail outlets practice selling with a cut that is a multiple of 1 meter.

Numerous accessories are on sale for all pipes - threaded fittings, for switching to another type of pipes, with external or internal threads or with an American union nut, couplings, tees, transitions in diameters, bends at an angle of 90 and 45 degrees, plugs, bypass loops , compensators and other necessary details. In addition, it is possible to purchase taps, valves, manifolds, "oblique" coarse water filters designed for direct soldering into polypropylene piping.

In a word, such a variety allows you to choose the most convenient scheme for assembling a system of almost any degree of complexity. The cost of most of these parts is very low, which allows you to purchase them with a certain margin, if only in order to conduct a small training session before starting practical installation - so to speak, “get your hand on”.

Methods for connecting polypropylene pipes

Polypropylene is a thermoplastic polymer - when heated, its structure begins to soften, and when two fragments evenly heated to a certain temperature are joined, mutual diffusion occurs, or rather, even polyfusion, that is, the material interpenetrates. When cooling, the properties of polypropylene do not change, and with a high-quality connection - ensuring optimal heating and the required degree of compression, after the reverse polymerization of the boundary as such, there should not be a completely monolithic assembly.

It is on this property that the main technological methods for connecting polypropylene pipes are based - this method is often called polyfusion welding.

Such welding (soldering) can be carried out by coupling or butt welding.

• Socket welding is just the technology that is most often used when installing plumbing or heating circuits in a house or apartment. It is designed for pipes of small and medium diameter, up to 63 mm.

Its meaning is that any connecting unit involves the use of two parts - this is the pipe itself and the coupling, the inner diameter of which is somewhat smaller than the outer diameter of the pipe. That is, in a normal, “cold” form, the parts cannot be paired. The coupling can act not only, sorry for the tautology, the coupling itself, but also the mounting section of the tee, branch, tap, threaded fitting and other components.

The principle of such welding is shown in the diagrams below.

The pipe (pos. 1) and the coupling or any other connecting element (pos. 2) are simultaneously mounted on the heating elements of the welding machine.

A pair of the required diameter is coaxially installed on the working heater itself, consisting of a metal sleeve (pos. 4), into which the pipe will be inserted, and a mandrel (pos. 5), on which the necessary connecting element is put on.

During the heating period, a belt of molten polypropylene is formed along the outer surface of the pipe and the inner surface of the coupling, approximately the same width and depth (pos. 6). It is important to choose the right warm-up time so that the melt process does not capture the entire wall of the pipe through and through.

Both parts are simultaneously removed from the heater, and coaxially, with force, are connected to each other. The molten plastic outer layer of polypropylene will allow the pipe to fit tightly into the sleeve until it stops, for the length of the heated section.

At this stage, the process of polyfusion, cooling and polymerization takes place. As a result, a reliable connection is obtained, which, although shown in the diagram by a shaded area (pos. 7), but in reality, if you look at the section, you can’t see it at all - it’s almost a monolithic wall.

• Butt welding is done a little differently.

One of the main differences is that the parts that are joined must be the same in inner and outer diameter.

The first step is to fine-tune the ends so that they fit perfectly together.

Pipes are pressed from both sides with a facer - a rotating disk (pos. 2) with precisely set knives (pos. 3)

The pipes are again pressed to the center, and at the ends, for the entire thickness of the wall, polypropylene melting areas are formed (pos. 5).

And, by analogy with the previous case, as the weld cools, it polymerizes, creating a reliable connection between the two pipes.

The principle seems simple, but it is only at first glance. With this welding technology, the most accurate alignment of the mating parts is of decisive importance. In addition, in sleeve welding, the required degree of compression of the mating melted areas is provided to a greater extent by the difference in the diameters of the parts. In this case, the application of a significant external force is required, directed strictly along the axis of the connected pipes. All these conditions can be met only when using a special, rather complex machine-type apparatus.

There are many devices for butt welding, but almost all of them have a powerful frame with guides and clamps for clamping pipes of various diameters - to ensure the alignment of the connection, removable or reclining trimmer and heater, a mechanism for creating the required compression - manual, hydraulic, electric, etc. .P.

This technology is used, as a rule, only by professionals when laying main pipes, and the probability of encountering it at the household level is practically zero.

There is also a "cold" method of welding - using glue based on a potent organic solvent. The point is that when treated with such a composition, the surface layers of the polymer soften. Parts can be connected at this time in the desired position, and since solvents are usually highly volatile, they evaporate quickly. then the process of reverse polymerization begins quite quickly.

This technology is more suitable for polyvinyl chloride (PVC) pipes that do not have the proper thermoplasticity. In addition, a similar connection method has, perhaps, more disadvantages and limitations in use than advantages, therefore it is not in particular demand, especially since there is a simple and accessible technology for socket polyfusion welding.

What is required for installation work

So, in the future we will consider exclusively sleeve polyfusion welding (soldering). To cope with this task yourself, you need to prepare a number of tools and accessories.

• First of all, it is, of course, a machine for welding polypropylene pipes. There is such a tool - not so expensive, and many zealous owners already have it in their home "arsenal".

Coupling-mandrel kits of the required diameters must be attached to the welding machine. Most devices allow you to simultaneously place two, and sometimes three pairs of working nozzles on their heating element, which allows you to install a system that uses pipes of various diameters without interruptions for replacement.

If you don’t have your own device, and circumstances at the moment do not allow you to purchase it, then many salon shops practice short-term rental with a daily fee - you can take advantage of this opportunity.

If you decide to buy a machine for welding polypropylene pipes ...

All welding machines are arranged in approximately the same way and work according to a similar principle, however, they also have certain differences in layout and functionality. Useful information for those who decide on such a purchase is available in the article of our portal, specially dedicated to.

In the text, there may be a definition of an apparatus for soldering pipes - but this is just a "play on words." There is no difference between these concepts in this case.

• Pipe cutting requires special scissors. Moreover, they must be sharply honed, with a serviceable ratchet mechanism that provides a smooth cut. The blade must be free of nicks or warps.

Of course, you can cut the pipe with a hacksaw, just with a metal blade or even a “grinder”, but this is absolutely not a professional approach, since such tools cannot achieve the required accuracy and evenness of the cut.

machine for welding polypropylene pipes

• It is necessary to prepare a marking tool - a tape measure, a ruler, a building square, a marker or a pencil. To properly place the pipes, you have to resort to the help of a level.
• If you plan to solder polypropylene pipes with aluminum reinforcement, then additional tools are needed.

- if the pipe has external reinforcement, then a shaver will be required, which will clean the aluminum layer at the point of penetration.

- if the aluminum reinforced layer is located deep in the wall thickness, then the pipe still requires preliminary preparation, but in this case a trimmer is already used.

The trimmer outwardly often looks like a shaver, but there is a difference between them - it lies in the location of the knives. For a shaver, the cut is tangentially parallel to the axis of the pipe, and for a trimmer, as even their names are clear, the knife processes the butt and removes a small chamfer.

Read a useful article, and also check out the varieties and selection criteria on our portal.

We will dwell on this point in more detail when considering the technology of soldering pipes.

• Many people overlook this, but the welded sections of pipes and couplings must be cleaned of dirt, dust, moisture, and then degreased. This means that it is necessary to prepare a clean rag and an alcohol-containing solvent (for example, ordinary ethyl or isopropyl alcohol).

But solvents based on acetone, esters, hydrocarbons should not be used, since polypropylene is not resistant to them, and the walls can float

• Care must also be taken to protect the hands. They will have to work in close proximity to the heating element of the apparatus, and getting a serious burn is as easy as shelling pears.

Suede work gloves are best for this business - they practically do not restrict movements, they will not start to smolder from contact with a hot heater, and they will reliably protect hands.

And one more important warning. Most installation work can often be carried out out of place, but, for example, on a workbench in the workshop - some devices even have special brackets with clips for secure fixation on the table. This is convenient in the sense that the assembled unit is then quickly installed, for example, in cramped and uncomfortable conditions in a bath or bathroom.

In any case, wherever soldering is carried out, high-performance ventilation must be ensured. When polypropylene is heated, a gas with a pungent odor is released. The smell is not the worst thing - with prolonged inhalation, serious intoxication can occur. Believe me, I've tested it on my own skin. The author of these lines lay around for a day with a temperature of 39 ° after seven hours of work in a fairly spacious combined bathroom, with a seemingly well-functioning ventilation outlet. Do not repeat mistakes!

How to solder polypropylene pipes

General technological methods for welding polypropylene pipes

• First of all, the novice master must clearly understand what he is going to mount. A detailed drawing should be prepared, with dimensions and specific details indicated - the same “document” will become the basis for acquiring the required number of pipes and components.
• If conditions allow, for example, in the room where the installation will be carried out, there is still no finishing, then it is best to transfer the scheme directly to the walls - this will be more clear, and you can measure the required pipe lengths literally in place.

The key to success is to try to complete the maximum possible number of nodes in a comfortable working position, on a workbench. Working with a soldering iron directly on site, and even alone, without an assistant, is an extremely difficult task, and it is very easy to make an error in this case. It is clear that such operations cannot be completely avoided, but their number should be reduced to a possible minimum.

• The soldering iron is getting ready for work. On its heater, working pairs are put on and tightened with a screw - couplings and mandrels of the diameters necessary for operation. If it is supposed to work with one type of pipe, then there is nothing to be wiser - one pair is put on, as close as possible to the end of the heater.

There are welding machines with cylindrical heating elements - it has a slightly different fastening of working elements, like a clamp. But understanding this is easy.

• It will be much more convenient to work if the device is rigidly fixed to the working surface of the workbench. It's great if the design provides for a clamp-type screw for mounting on the edge of the tabletop. But even with a conventional apparatus, you can try to come up with some kind of fixation. For example, if the surface allows, the legs of the stand are screwed to the workbench with screws.

Even with a fixed stand, the device can "wobble" in it - there will definitely be a backlash. Here, too, you can provide for your own fastening - drill a hole and screw in a self-tapping screw. When a soldering iron is needed for remote work, removing this mount is a matter of a few seconds.

• The soldering iron is connected to the network. If it has a temperature control, then approximately 260 ° C is set - this is the optimal temperature for working with polypropylene. You should not listen to anyone that for the 20th pipe you need 260 degrees, for 25 - already 270, and so on - on the rise. The temperature is the same, the heating time of the mating parts just changes. In any case, those tables that the manufacturer attaches in the product passport, and which will be placed below in this article, are designed specifically for this level of heating.
• Usually there is a light indication on the soldering iron. A burning red light indicates that the heating element is working. Green - the device has reached the operating mode.

However, many models have their own display features. Some devices even have a digital display with temperature indication. In any case, the device will “let you know” that it has warmed up to the required level.

• The mating parts are being prepared for work - the necessary piece of pipe is cut off, the connecting element is selected, according to the installation scheme.

• Not many people do this, but meanwhile the technology requires - obligatory cleaning of the connection area from possible dirt and dust, and degreasing. In addition, even the slightest droplets of water or a wet surface are completely unacceptable - water vapor can get into the melt layer, create a porous structure there, and this connecting unit runs the risk of leaking sooner or later.
• The next step is to mark up the connection. On the pipe, it is necessary to measure from the end and mark the length of the penetration zone with a pencil (marker). It is up to this mark that the pipe will be inserted into the heating sleeve, then into the connecting piece. Each diameter has its own value - it will be indicated in the table below.

The second mark is applied if the relative position of the mating parts matters. For example, a 90° bend is already welded on one of the sides of a pipe segment, and on the other, a tee is to be mounted, but so that its central channel is located at an angle to the bend relative to the axis. To do this, first accurately determine the position of the parts, and then put a risk across the border, on both.

There will no longer be a lot of time to choose the correct position during soldering, and such a “trick” will help to accurately position the mating parts.

• The next step is directly soldering the connection. It, in turn, also includes several phases:

- From both sides, the pipe is simultaneously inserted into the soldering iron coupling, and the connecting element is put on the mandrel. The pipe should go to the mark made, the connecting element - to the stop.

— Once the pipe and connector are fully inserted, the warm-up time begins. Each diameter has its own optimal period, which should be followed.

- Once the time has elapsed, both parts are removed from the heating elements. The master has literally a few seconds to give the parts the correct position and, of course, alignment, insert one into the other with effort and bring it to the same mark. Light adjustment, without turning around the axis, is only allowed for one or two seconds.

- In this position, the parts must be held, without the slightest displacement, for the specified fixation period.

- After that, the assembled unit should not experience any load during the set period of cooling and polymerization of polypropylene. And only then can it be considered ready

Now - about the main parameters that must be followed during installation. For ease of understanding, they are summarized in the table:

As for reducing the set warm-up time (with the exception of the case mentioned in the note to the table), there can be no question - a high-quality connection will not work, and the node will surely leak over time. But about some slight increase - the masters have no unity of views. The motivation here is that pipes from different manufacturers may differ slightly in material, that is, there are more rigid or, conversely, softer polypropylene. But the masters have accumulated experience, accurate knowledge of the material used, and for a beginner, the recommended indicators should still be taken as a basis.

Good advice - when buying pipes and accessories - take a small supply of the cheapest connecting elements, and conduct an experiment - training. You can prepare several pieces of pipe and perform trial soldering.

With high-quality soldering, a neat bead about 1 mm high is created around the circumference of the connecting node, which will not interfere with the free passage of water. Outside, a neat bead will also be formed that does not spoil the appearance of the connection.

pipe cutter

But overheating is already fraught with getting a defective connection. Molten polypropylene begins to squeeze inward when the parts are combined, where a “skirt” is formed and solidifies, which largely closes the passage. The pressure of water in such a water supply can be reduced, and in addition, such a defect often becomes a place of blockage over time.

Conducting such a practical lesson will help you accurately determine all the soldering parameters and avoid mistakes.

Features of working with pipes with aluminum reinforcement

As mentioned above, two options are possible here - the reinforcement layer is located near the pipe surface, or in the depth of the wall. Accordingly, the methods of preparing the pipe for welding also differ.

• It is clear that the aluminum layer located near the surface simply will not allow for a full heating and connection of the assembly. In addition, such pipes always have a slightly higher diameter, and simply will not enter either the heating sleeve or the connecting element. This means that it is necessary to clean off this layer to “clean” polypropylene.

For this, a special tool is used - a shaver. A piece of pipe is inserted into it and they begin to rotate - the installed knives carefully cut off the upper polymer coating and the aluminum located under it.

Processing is carried out until the pipe stops at the bottom of the tool - the dimensions of the shaver are such that it cuts the foil exactly in the strip that is required for the welded joint at a given diameter, that is, you can even not carry out the appropriate marking.

When soldering, the entire cleaned area must be heated, and then completely inserted into the connecting part. Leaving even a thin strip of a protected pipe outside is prohibited.

• If the aluminum foil is hidden in the skin of the material, then it would seem that it does not fit in any way with high-quality soldering. But there is already another nuance here.

If the pipe is not protected from the end, then the water passing under pressure will try to delaminate it, find a way out between the aluminum layer and the outer polypropylene shell. Aluminum, in addition, may begin to corrode, lose its strength. The result of such stratification first becomes "blisters" on the body of the pipe, which then necessarily end in a major accident.

The way out is to create such conditions that during welding the end of the pipe and the aluminum layer would be completely covered with molten polypropylene. And this can be achieved by processing with a special tool, which was mentioned above - with a trimmer.

Outwardly, it may be similar to a shaver, but its knives are located differently - they will precisely align the butt, cut off the chamfer and remove a thin, about 1.5 - 2 mm from the cut, strip of aluminum foil around the circumference. During heating and during the mating of parts, the created bead of molten polypropylene will completely cover the end of the pipe, and the assembly will receive the necessary reliability.

Pipes with fiberglass reinforcement do not have any installation features.

• The soldering process, as mentioned, is best done on a comfortable spacious work area, assembling ready-made water supply units (heating circuits) to the maximum, and only then installing and connecting them in place.

The work "near the wall" is always more complicated, time-consuming and nervous, since one has to hold a fairly heavy apparatus with one hand, while simultaneously providing heating for both mating parts. Often, without an assistant, such a welded joint is almost impossible to perform. Therefore, it is worth minimizing the number of such operations.

But at the same time it is important not to make an oversight. To connect the assembly, it is necessary to provide a certain degree of freedom to the mating parts - they need to be moved apart to install a welding machine between them (plus, the heating pair also has a certain width), then carefully, without skew, insert into the mandrel and coupling, after warming up, ensure translational removal and then connection. It is necessary to foresee this moment in advance - will the existing backlash be enough to perform all these manipulations.

• It happens that inexperienced craftsmen, without foreseeing this nuance, are faced with the fact that the last weld is left, and there is no way to complete it. What to do?

The way out can be welding into a cut pipe a collapsible connecting pair - a threaded fitting and a coupling with an “American” union nut. The connection is reliable, and soldering such elements even in such difficult circumstances is no longer difficult.

• If at least some node during installation raises even the slightest doubt, without any regret it should be cut out and other parts welded in. Believe me, it will not take much time and will not entail serious costs. But if over time such a dubious area suddenly leaks, the consequences can be very sad.
• The next group of errors has already been mentioned above - this is a violation of the pipe soldering technology. This may include insufficient or excessive heating. The force applied to the parts when connecting should be in moderation. Too much compression will result in the formation of an internal "skirt". Equally dangerous is the insufficient application of force - the pipe does not enter the socket of the connecting part to the end, there remains a small area with an increased diameter and a thinner wall - a potential breakthrough!

• Do not forget about cleaning the parts to be welded from dirt and grease. Perhaps this seems insignificant, but in practice there are quite enough cases when such neglect subsequently turned into a weak connection and the formation of a leak.
• Attempts to change the position of the parts during the setting and cooling of the connection are very dangerous. Outwardly, this may not manifest itself, but microcracks appear in the connecting seam, which subsequently lead to accidents. If you don't like the connected node - "into the furnace" it, and make a new one, but don't try to change it!
• When stripping a reinforced pipe, even a tiny piece of foil should not remain in the cleaned area - this can become a potential site for a future leak.
• One more recommendation. It is clear that the material must be of high quality - you should not chase cheapness, since you can lose much more, especially since even branded polypropylene pipes and accessories for them are not so expensive. But there are cases when, during the installation of high-quality pipes, carried out with strict adherence to technology, the connecting nodes nevertheless began to fail over time. And the reason is simple - really high-quality material was used, but from different manufacturers. Seemingly insignificant differences in the chemical composition and physical and technical characteristics of polypropylene gave such an unexpected result - full-fledged diffusion of melts was not achieved.

Therefore, a final tip: use high-quality pipes from one manufacturer. It is probably clear that all components must also be of the same brand.

At the end of the publication - an informative video about the soldering of polypropylene pipes:

Video: the master shares the secrets of high-quality soldering of polypropylene pipes

From the side it seems that there is nothing particularly difficult in welding polypropylene pipes: heat, connect, cool - it's ready. However, in practice it turns out that in this case there are a lot of important points that affect the quality of the connection of pipes and fittings. Neglecting these nuances leads to various flaws that cause clogging, leaking pipes and other problems. Some of the errors are discovered only a few months after the start of operation of the pipeline, when the unfortunate masters are already gone.

A little about the soldering process

For welding pipes and fittings made of polypropylene, the thermal polyfusion method is most often used. Its essence is to heat the parts to be welded to a certain temperature and quickly connect them. To heat the parts, a special device is used, popularly referred to as a "soldering iron". The process of soldering plastic pipes is clearly presented in the video:

Some manufacturers of heaters for soldering plastic pipes install two heating elements on one device at once. (This is typical for inexpensive models of Chinese and Turkish production). A separate switch is provided for each of them, and the power of each such element is enough to heat pipes and fittings of a specific diameter. Do not use two heating elements at the same time, so as not to overheat the plastic, overload the network and not consume excess electricity. The second heater should be used as a spare, necessary in the event of a breakdown of the first.

If the welding device is equipped with two heating circuits, they can be turned on simultaneously at the start of work in order to heat up the tool faster. Then one of the circuits should be turned off.

The use of a device for welding pipes made of polypropylene does not require special skills. However, novice installers should practice a little before starting work.

The heated pipe material retains plasticity for some (very short) time. In these seconds, you need to connect the elements and fix the connection, while eliminating distortions. Only at the end of the “fixation” phase, when the material has lost its elasticity, can the connected pipes be placed on the table.

The optimum temperature for heating polypropylene pipes is considered to be a temperature of 260 degrees. During the heating process, it is necessary to heat the pipe material strongly enough to ensure a reliable connection. In this case, the pipe must not be overheated so that it does not lose its shape. To do this, you should monitor the heating time. Depending on the diameter of the pipes, it can be:

• 8-9 seconds for pipes with a diameter of 20 mm;
• 9-10 seconds for pipes with a diameter of 25 mm;
• 10-12 seconds for pipes with a diameter of 32 mm, etc.

If the pipe is not heated to the required temperature, the connection will be too weak, and over time, a leak will form there. Overheating of the pipe can lead to sagging and a decrease in its permeability.

The table shows the estimated welding time for polypropylene pipes depending on their diameter. You should not violate these deadlines so as not to spoil the work

There are models of devices for with or without a temperature control knob. The ability to vary the temperature was dictated more by the manufacturer's marketing considerations than by practical necessity. Professionals recommend setting the temperature correctly (260 degrees) and not changing it in the future, focusing on the heating time. Therefore, the old models of "soldering irons", in which there is no heating temperature controller, are quite suitable for high-quality welding of polypropylene pipes.

The pipes are warmed up and connected, now it is important to cool them properly. It takes the same amount of time to complete the “fixation” phase as it does to heat up. Inexperienced masters are in a hurry, stop the process before these few seconds, which causes deformation of the connection. Do not think that a stopwatch is indispensable for working with polypropylene pipes. Experienced craftsmen calculate the heating-cooling time automatically, without any devices.

The range of errors made when welding polypropylene pipes is quite extensive. Most often it is:

1. Contamination at the junction of elements
2. A small amount of water that has come into contact with the material during the welding process
3. Long-term positioning of pipe parts
4. Use of unsuitable or poor quality material
5. Failure to comply with installation rules, etc.

It is not difficult to avoid these mistakes if accuracy, caution and a high professional level of performers are observed during welding.

The figure schematically shows the appearance of correct and incorrect butt welding of polypropylene pipes. To avoid such errors, it is necessary to follow the installation technology

You may also find the material on choosing a soldering iron for polypropylene pipes useful:.

Mistake # 1 - dirt and water on the connected elements

A professional installer must wipe all parts to be welded before starting work to remove possible contamination. You should also pay attention to the condition of the floor in the room where the welding is performed, since the pipes are laid on the floor, and dirt again gets on them. When dismantling a faulty pipe, it is not uncommon to find a clear line of dirt along the entire length of the connection.

The rest of the water in the pipe can be fatal for the connection. A few drops in the process of heating turn into steam, the material is deformed and loses strength. To remove water from the pipe, it is enough to fill it with salt or push crumpled bread crumb inside. At the end of the work, the pipe, of course, should be thoroughly rinsed. A connection with such flaws can remain stable even when pressure tested, but after some time (sometimes it can take a whole year), a leak will definitely appear. A similar error occurs when welding stabilized pipes if the foil from the intermediate layer is carelessly removed. Even a small piece of foil at the junction will significantly degrade the quality of the installation.

Not only pipes should be clean, but also a soldering iron. The master should promptly remove particles of molten polypropylene from all elements of his tool, otherwise they will fall on the next pipe.

Mistake #2 - wrong positioning

After the two heated parts of the pipe are connected, the master has only a few seconds to put them correctly relative to each other. The shorter this period, the better. If the time limit is exceeded, the deformation becomes irreversible and the strength of the joint is reduced.

Inexperienced craftsmen sometimes try to immediately remove the splashes that appeared during the welding process. You should not do this, since the uncooled connection at this moment can be easily deformed. Remove slugs after the joint has cooled. And it’s even better not to overheat the pipe, then the splashes simply will not appear.

Mistake #3 - wrong material

If inexpensive low-quality polypropylene pipes are chosen for installation, even the most skillful installation will not protect the owners of the house from breakage. It is best to purchase pipes and fittings from the same reliable supplier, choose a good company, etc. The miser pays twice.

Another problem of this kind is an attempt to connect two high-quality pipes from different manufacturers. The chemical composition of such elements may vary, therefore, such pipes will behave differently when heated. Under such conditions, it is almost impossible to achieve a reliable connection.

Visual result of incorrect soldering of polypropylene pipes in the section. The use of low-quality material and non-observance of the time of the “fixation” phase led to deformation of the connection

Mistake #4 - neglecting the installation rules

The poor quality of welding of polypropylene pipes is caused by various errors during the connection of the fitting and pipe. For example, if the pipe is not completely inserted into the fitting, a gap will form between its edge and the inner stop of the fitting. The result is a place where the inner diameter is larger and the wall thickness is smaller than planned. The design operating pressure for this section will not be high enough, normal loads may be excessive here, resulting in a leak.

It is also unacceptable to use excessive force when inserting the heated end of the pipe into the fitting. In this case, a significant slum can form inside. As a result, the permeability of the pipeline will be lower than the calculated values, which will adversely affect the operation of the pipeline.