Various methods of welding polypropylene pipes

The era of steel and pig iron pipelines is gradually becoming a thing of the past. Today, for household purposes, plastic pipes, in particular, polypropylene pipes, are used. One of their undoubted merits is that they are easily installed. That is, in order to collect the pipeline does not necessarily resort to the help of professionals. But if the home master wants to build a water supply or heating system on his own, he will have to master the process of welding polypropylene pipes. Fortunately, it's much easier to learn to weld them than metal ones, and equipment for welding polypropylene pipes is cheaper than a welding machine.

Today many people face the need to install new polypropylene pipes. Someone needs to replace the old metal pipe, someone arranges a dacha or a country house, installing water, heating and sewerage there.

Polypropylene pipes have many advantages over steel pipes. First, they are cheaper, and secondly, you can build the pipeline yourself, and thirdly, plastic pipes are more durable than steel, because they are not subject to corrosion.

It is possible to join pipes without a soldering iron using a special glue or sealant. That such cold welding was qualitative, it is necessary to apply glue composition evenly. If the glue is in tubes, then it is recommended to use a special gun.

But still, when welding, connections are more reliable and are more often performed by them. Especially since welding polypropylene pipes by oneself - the process is quite simple, it is easy to master any home master.

Tools for welding pipes from polypropylene

If it is decided to mount pipelines using propylene pipes - welding of its individual elements can be done by the home master himself. But to carry out this work, you will have to purchase a tool for welding polypropylene pipes.

Advice! If a single welding job is planned, you can not spend money on purchasing a welding machine. Sets for welding polypropylene pipes can be borrowed and rented.

As a rule, the connection of PP pipes is carried out by diffusion welding. The basis of the process is heating to the melting point of the ends of the welded parts and their connection in a hot state. After solidification a monolithic joint is formed.

To heat the parts, an iron is used for welding polypropylene pipes, which works on electricity. The device for welding is quite compact, so it is easy to transport.

In addition, the light weight of the apparatus makes it possible to weld at the installation site of the pipes, if necessary. The device is equipped with a temperature regulator, in addition, the set includes a nozzle for welding polypropylene pipes - a set of different diameters.

Used attachments

In order to be able to connect polypropylene pipes, nozzles of different sizes are included in the delivery set. Their use makes it possible to weld pipes differing in diameter.

The purpose of the nozzles is to heat the outer or inner surface of the workpiece to be welded. Typically, a standard kit, includes nozzles with a diameter of 16 to 40 mm. If it is necessary to weld large-diameter polypropylene pipes, the kit can be refilled by purchasing nozzles separately.

As a rule, the nozzles have a special coating of Teflon, due to which the heated parts are better removed and do not stick. The nozzles consist of two elements:

• Elements with a hole are used to insert pipes into them.
• Elements having a collar are used to fit a fitting on them.

Thus, when the machine is switched on, the inner part of the pipe and the outer fitting of the fitting are heated simultaneously. To fix the necessary nozzle on the machine is not difficult, for this purpose bolts are used that come with the device.

Pipe Cutters

In order to obtain a good weld, the instruction for welding polypropylene pipes requires that the connection of individual parts be made strictly at right angles. Quickly and accurately cut them into the right lengths will help a special device - a pipe cutter.

Cutting can be done using a hacksaw for metal, but without using pipe cutters, it is much harder to get an accurate cut.

Additional Tools

If the home master purchased a welding device and a pipe cutter, a very small set of tools would be required for a quality welding process:

• Roulette for measuring segments.
• Level to control the horizontality of their placement.
• Patterns for cutting holes if the network has branches.
• A marker or an ordinary pencil for marking.

The technology of welding polypropylene pipes is simple. The welding of polypropylene pipes according to the instructions takes place in three stages:

• Simultaneous heating of both parts to be connected.
• Removal of parts from nozzles and their connection into a single structure.
• Cooling of molten plastic and formation of a monolithic seam.

• In order to weld the PP pipes was performed qualitatively, the welded surfaces should be well prepared. Namely: clean from dirt and dust, and be sure to degrease. The latter condition is for some reason often ignored by the home masters, and yet the quality of the seam depends on the performance of this small operation.
• Before heating, the end of the pipe and the fitting must be degreased. What solution should I use? Best of all, alcohol. Wiping will remove the small crumb formed during the cutting process, which, as an abrasive, will act on the nozzle of the soldering iron, destroying its Teflon coating.
• It is recommended to wipe the nozzles immediately before installation with alcohol. This simple operation will help to eliminate the possibility of sticking plastic to the surface of the nozzle and the need for its mechanical removal.

• If socket welding is performed, then the marking of the depth of the pipe fitting is also mandatory. The fact is that the fittings used can have different depths of the welded joint, so before starting the heating it is necessary to measure this depth using a conventional ruler or caliper. If no markings are made, there is a high risk of error during the introduction of the pipe into the opening of the connecting fitting. If the insertion is too deep, the inner section of the pipe will be narrowed, which will lead to a decrease in its throughput. If the insertion is not deep enough, the strength of the connection will be reduced.

Advice! Many professionals determine the depth of landing by eye, but this skill can be acquired only with considerable experience. Therefore, a beginner master should take the time to complete the markup.

• If welding PPR pipes is carried out in a horizontal plane on the desktop, then the work is easy to handle and one person. However, during installation, there is often a need to weld parts at the place of installation, and the welding position can be quite inconvenient. Compact welding machines for polypropylene pipes allow you to perform such welding, but the master will need an assistant.

• When connecting the PP pipes - welding should be done as accurately as possible. It is necessary to strictly maintain the heating time (information on the time of heating pipes of different diameters is in the passport of the device, since this time depends on the power of the soldering iron used). If the parts of the hermetic joint are not heated sufficiently, it can not be obtained, and if they are retained on the heating nozzles, it is possible to form buildups inside the pipe, then it will narrow its internal diameter.
• Details removed from the heating nozzles should be quickly connected, given the depth of planting. In this case, it is impossible to make twisting or jiggling movements. The time for performing the adjustment of the connection is very limited, at the disposal of the installer no more than 2-3 seconds. Therefore, you should try to immediately connect the details as accurately as possible.
• After making the connection, it is equally important to correctly withstand the time of hardening of the welded seam. It depends on the diameter of the pipes used and the ambient temperature. To prevent instant solidification of plastic, welding of pipes from polypropylene is never done at too low temperatures, the room should be at least 10-15 degrees of heat.

If the home-based craftsman does not have the experience of joining polypropylene pipes with welding, he should carefully study the instructions that are attached to the welding machine. There are tables showing the time of heating and subsequent soaking, as well as detailed recommendations for welding. Do not put and clearly see how the welding of polypropylene pipes - video with a detailed description of the process is easy to find on the portals dedicated to construction topics.

As experts say, the use of polymer pipes in heat and water supply has made a real revolution in construction. The main advantages of these materials are high corrosion resistance; low weight; in the smoothness of the internal surface, which provides a lower hydraulic resistance than conventional metal pipes; relatively low cost (again compared to metal products); convenience of installation, high wear resistance (the service life of the polymer pipe can be 50 years or more). Although such pipes have certain disadvantages: low temperature stability, gas permeability, low operating pressure, large linear expansion and difficulties with the use of reliable threaded connections. All this significantly limited their use in hot water supply and heating, until new types of materials, methods of installation and technology for the production of polymer pipes were developed.

The main material for the production of such products is a special type of thermoplastic polymer. One line for the production of polyethylene pipes makes it possible to produce high and low pressure pipes from various polymer materials such as polypropylene, polybutene, polyvinyl chloride, etc. Polyvinyl chloride, for example, has the same quality as fire safety, which is explained by its high ignition temperature (+440 ° C) and an oxygen index of 60%. However, the main disadvantage of polyvinyl chloride is the increased rigidity of this material, which greatly complicates the work with it.
   Polyvinylchloride is formed by polymerization of vinyl chloride. It can be of two types: chlorinated and unplasticized polyvinyl chloride. PVC is a sufficiently strong, easy-to-use and resistant to external influences materials. But the area of ​​its use is limited due to increased toxicity and rapid ignition. For these reasons, such pipes are used mainly for drainage and sewerage equipment. But on the other hand, PVC products have a number of advantages: resistance to corrosion, low thermal conductivity, smooth surface inside, stiffness. Like other polymers, PVC is unstable to sunlight, oxygen-permeable and requires the use of special assembly and welding equipment.

Polyethylene pipes are characterized by low cost, convenient for welding, and their production does not require large investments. However, they are not sufficiently heat-resistant and strong, so they are rarely used for heating (only pipes made of special polyethylene for increased temperature). In our country, the production of PE-PE-type pipes predominates, although the material of the new generation PE100, which is more durable and heat-resistant, has become widespread in the West. Pipes from PE 80 in our country produce a fairly large number of companies (for example, OJSC "Kazanorgsintez", LLC "Stavrolen"), and PE 100 - units (they are sporadically produced by the plant IDT "Gaztrubplast" and JSC "Kuzpolimermash"). Another rather promising direction for development is the production of PE pipes for high temperature - PE-RT. While in our country, products from this polymer are sold only to the Polish company KAN. However, Russian entrepreneurs are still in no hurry to introduce pipes from PE-RT into their assortment, believing that they are too expensive at a price (comparable to the cost of pipes made of metal-plastic and PE-X) and still have a number of shortcomings in comparison with metal-plastic products (lower pressure, degree of resistance to chlorine, etc.).

In addition, three modifications of polypropylene are used for pipe production: PP-B block copolymer, PP-H homopolymer and a propylene-propylene static copolymer with PP-R ethylene. Each of these types of materials is used for certain pipes. For example, PP-H is used for the construction of technological pipelines, PP-B is used in sewage systems, and PP-R, due to its high strength, is used in hot heating and heating. However, polypropylene in the construction of heating systems is gradually inferior in Europe to pipes based on PE-X. In our country it is still popular, as it has good weldability. And this advantage compensates for domestic builders all the shortcomings: relatively high speed of crack propagation, rigidity and high linear thermal expansion (in comparison with metal-plastic pipes). However, in systems of cold water supply and sewage, polypropylene prevails over PVC, as it has a higher chemical and thermal resistance than the latter.

Leaders in the market of polypropylene pipes are foreign producers Aquatherm and Polymelt Kunststoftechnik. Among the Russian manufacturers of polypropylene pipes, we can name Stroypolimer, Borodino-Plast and Agrigazpolimer. The main difficulty in the production of propylene products is the need to purchase certain raw materials. The best raw material is the products of the Swedish company Borealis, but it is significantly (about 150 euros per ton) more expensive than similar raw materials of other German, Korean, Hungarian and even Russian companies.

The aforementioned PE-X is the so-called crosslinked polyethylene. This technology of pipe production has appeared relatively recently. Advantages of cross-linked polyethylene consist in the best indicators of toughness at low temperatures, in chemical resistance, minimum long-term strength and resistance to spreading cracks along the surface of the pipe. However, this material is unstable to the effect of petroleum products and products of their processing (oils, solvents, fats).

The purpose of the pipe and the material from which it is made can be determined by its marking and coloring. So, for example, pipes of black color are made of polyethylene, orange and yellow-pink - from polyvinyl chloride, gray - from polypropylene. When manufacturing, the pipes are marked in the form of multicolored strips. Longitudinally applied stripes of blue and blue colors are marked pipes for cold water supply, and strips of white color mark pipes in heating and hot water supply systems. Pipes of yellow color are used for gas pipelines. For the production of pipes from polymeric materials, an extrusion line is used for the production of polyethylene pipes. Gas pipes are usually yellow.

For the production of pipes from polymeric materials, special extrusion lines are used for the production of polyethylene pipes. Such equipment is usually made to order in accordance with customer requirements. Functionality and configuration of the line directly depends on several factors. In particular, it is necessary to take into account the type of material from which the pipes will be made, take into account the need for marking (this is also done on automated equipment), the desired equipment performance, pipe section dimensions and wall thickness.

From the technological point of view, the process of manufacturing pipes made of polymer materials is simple enough and does not require much time for training workers (for a month they can fully comprehend all the wisdom). The production line for the production of polymer pipes by extrusion operates on the principle of a continuous and closed cycle. It consists of several basic elements. A single-screw extruder is a worm press inside which a homogeneous mass of polymer substance is formed and proportionally divided into several parts (their exact number depends on the length and width of the pipe) using a molding head. The extruder is activated by means of a drive. High-speed pipe heads are made on a spiral principle, which allows to provide the necessary extrusion. They also control the temperature. The vacuum calibrator uses compressed air, which forms the diameter of the tube. This is especially important in the production of water pipes, because it allows you to accurately calibrate their internal diameter, which is necessary for accurate docking. The cooling sections are of two types: with an irrigation system or with a complete immersion of the pipe into the water. The main thing is that the cooling should pass evenly, otherwise the probability of getting a marriage is high. The pulling device removes the product from the head and pulls it through the cooling section. These devices can be of various types, depending on the size of the pipe: in the form of chains, belt or roller structures. The cutting device is an electric saw, which can be both circular and tape. The pipe is cut into lengths of the required length. The marker puts on the surface of the pipe information about the length, thickness and diameter of the product.

Granular plastic is used as the raw material, which is placed in the bunker compartment of the extruder. In this compartment there are annular heaters and auger, which melt the granules, forming a homogeneous viscous mixture. The molten pellets are fed to the extrusion head, through which they are extruded under high pressure, thus forming a future product. A molded polypropylene pipe is sent for vacuum calibration, where its cross-section is calibrated with a vacuum. In the same place, the blank is subjected to primary cooling. Then the tube moves through the cooling chambers, where it finally cools down, and then cut into segments of a given length. In order to ensure the drawing of a long pipe a special pulling mechanism with tracks is used. With this mechanism, the pipes are stretched without damage. To work with the line, you need 1-2 operators for one shift.

Such a line makes it possible to produce pipes with a diameter of 15 to 63 mm. Annual production capacity will be from 115,000 to 320,000 linear meters, depending on the thickness of the products. The installed capacity of current collectors is 20 kW, and the water consumption is 1 cubic meter. meter per day. To accommodate the line will need an area of ​​120-150 square meters. meters. Add to this the area of ​​administrative and domestic premises (20-25 square meters) and the area of ​​the adjacent territory (50-70 square meters). The cost of this line is from 3 million rubles. More expensive options will cost $ 150,000 or more. When buying a line (especially inexpensive), pay attention to whether it has an air preparation unit (air compressor and filter). Sometimes, for a line in the basic configuration, it may be necessary to buy a printer for marking on finished products, refrigeration units, etc.

The total amount of investment to create its own production of polymer pipes will be more than 6 million rubles. This amount includes rent of premises, purchase of equipment, wages to employees, purchase of raw materials. The payback period depends on the profitability, which can vary widely (up to 20-25%). On average, such an enterprise pays for itself within 2-2.5 years. However, consider the high level of competition in this segment. It is likely that the payback period will increase, if you can not ensure the sale of your products at favorable prices from the very start of your production. Therefore, the search for sales channels should be taken care of even at the stage of drawing up a business plan.

The era of water pipes from the metal has long ago passed. Such material as polypropylene, as well as the technology of welding polypropylene pipes, are at the forefront of our time, as regards the construction of water supply systems, heating, etc. in the house or apartment.

At the turn of the century, residents of the old high-rise buildings began to change the metal pipes to plastic ones, which at that time were still far from perfect and now require another replacement. Statistics show that today over 70% of pipelines are made of polypropylene.

At its cost, polypropylene pipes are cheaper than metal pipes, while the lifetime of such pipes is much higher, and the amount of effort required for their installation is incomparably lower. Among other things, the mass of polypropylene is the lowest among all polymers, and even polyethylene.

This fact, respectively, affects the reduction of transportation costs of the material, in addition, the compactness of the material can be achieved by investing pipes of smaller diameter in products with larger.

If you want to change the riser or, you do not need to hurry with the call of the master - all the work can be done independently, of course, with the desire and free time.

Working with polypropylene pipes

To date, the technology of installing polypropylene pipes has been developed, which includes the assembly of pipes of various diameters, as well as all necessary connecting elements, contours, inclusions, fastening and shut-off valves.

The complete set of the system is designed in such a way that it makes it possible to design a pipeline scheme of any configuration and complexity. The only minus of pipelines from polypropylene, and that indirect - impossibility of a connector at a welded way of connection.

Therefore, the technology of connecting polypropylene pipes requires extreme assembly, in order to avoid errors in the assembly.

However, the beginner in this case is waiting for a mass of possible missteps, connected mainly with inattention or haste. Before welding the pipe elements, several times you need to make sure that their calculations and dimensions are correct.

Now regarding soldering - the way of connecting polypropylene pipes with fittings and structural details. The tool used to conduct welding is called a soldering iron. And although from the point of view of technology this name is incorrect, such a simple and understandable term has taken root and has been applied even in the circle of professionals.

The process of welding polypropylene pipes is as follows:

1. the welding device (soldering iron) simultaneously heats both welded parts;
2. unite them;
3. after a short cooling time, the already prepared connection is removed from the apparatus.

Such a welded joint has such a tightness and strength that it can withstand almost any pressure.

Welding machine for PP-R pipes

In a set for welding polypropylene pipes, of course, includes a welding machine, which in its design is very simple and slightly different from the design of a conventional iron, except that its design.

The device also consists of a thermostat, a heating plate and a handle. The heating plate has two openings allowing the attachment of welded elements therein.

Since during the welding of polypropylene pipes, the pipe itself and any structural part (fitting) into which the pipe is inserted are usually used, then the pair of welding elements (attachments) of the apparatus are also outwardly different.

The most popular pipes used in domestic heating and plumbing systems are products with an outside diameter of 32 and 20 mm. Marking about the diameter is available on each polypropylene product.

The standard set for welding polypropylene pipes includes, as a rule, four pairs of welded elements, which can solve almost any problem - from 20 to 40 mm in diameter.

They are covered with Teflon coating, which makes the independent manufacture of this device impossible. And even if you manage to carve the elements on the lathe, which is not difficult, when heated without a Teflon coating, the plastic will stick to the metal.

Nuances of welding pipes from polypropylene

1. One of the main requirements, which is often ignored, is the degreasing of the surfaces of the elements to be welded. Of course, welding can be done without it, but the quality of the connection will be much lower.

Before starting the process, the end of the pipe and the inner surface of the fitting element should be wiped with alcohol. This also contributes to the removal of fine abrasive and dust particles from the surface, which adversely affect the integrity of the Teflon coating of the welding machine attachments.

Before the direct installation, the surfaces of the nozzles are also required to be examined and treated with alcohol to prevent the molten plastic from sticking, the subsequent mechanical removal of which teflon may be damaged.

1. The marking of the depth of planting of polypropylene pipes is no less important, which should be taken into account during the welding of polypropylene pipes.

Fittings of different calibers assume different depths of the welded joint. This means that the depth is with a caliper or ruler.

In this case, an error will not be made with the introduction of the pipe into the hole of the connected element deeper than the laid one. Otherwise, the cross-section of the opening can be narrowed or the tube can be sealed.

Advice! If you want to learn how to properly solder plastic pipes - video on the Internet, or the instructions attached to the welding machine, will be able to help you.

1. As a rule, pipe marking is a very troublesome task. Professionals determine the depth of planting by eye, but this experience is possible only after a long practice and not for everyone.

To facilitate the task, a special device is often made, which not only makes it easier to measure, but also saves time. Such a device for a pipe of 20 mm in diameter is made of a piece of pipe 32 mm in diameter.

At a depth of planting a 20 mm pipe at 15 mm, it is necessary to cut off a ring of 15 mm in width from a 32 mm pipe. The ring can be used to accurately mark the line, meaning the depth of the landing, which is very convenient when you need to weld a large number of elements among themselves.

The marking ring can be upgraded by gluing a plastic or cardboard bottom, which reduces the complexity of the marking process to a minimum. Similar rings can be made for polypropylene pipes of all diameters, except the largest.

Usually on the table or floor. But sometimes when assembling a pipeline, there is a need for welding pipes on site. Then without another pair of hands just can not do.

The assistant should be familiarized with how to properly weld polypropylene pipes.

In the process of welding pipes made of polypropylene, you should never hesitate. It is necessary to strictly observe the heating time of the connected elements, which is indicated in the corresponding table for each diameter, especially when welding is performed at the installation site, and there is no way to check the quality of the connection.

The most common oversight is the overheating of the parts, resulting in a narrowing of the pipe section.

Advice! When welding pipes at the site of a dislocation, one person should hold the welding machine, and the other should join the pipe and fitting first with hot welded nozzles, and then with each other. Alone, it is not always possible to remove both the pipe and the fitting from the soldering iron simultaneously. One thing can remain, and then the assistant should immediately help with the extraction.

The process of welding pipes made of polypropylene

1. Turn on the welding machine. The indicator of the power button should be on. Heating of the welding machine takes place within 10-30 minutes, depending on the ambient temperature. The operating temperature of the device is 260 degrees. If the device is used for the first time, after heating it is allowed to stand for 5 minutes, and only then begin welding.
2. The pipe and fitting are simultaneously inserted into the welding nozzle along one axis. Heating takes place according to the table and depending on the diameter of the elements to be welded.
3. After the end of the heating time, the fitting and pipe are removed from the welding machine and immediately connected, keeping them motionless for the specified time.
4. The cooled connection indicates that the welding is finished, and the parts can be used as a single unit.

So, the article on the topic "Polypropylene pipes: how to install and how to weld" is over. Now, if you install the pipeline yourself, you should not have any problems.

Soldering of pipes from polypropylene is carried out with the help of special apparatuses, which provide precise control over the time and temperature of melting of the parts. For cold water systems, cold (glue) welding is allowed.

How to choose the device?

In shape, all devices for welding polypropylene pipes are divided into:

• X-ray ("irons"): inexpensive devices designed for welding pipes with a diameter of up to 40 mm, with a plate-shaped heating element in the holes of which are inserted paired nozzles - replaceable couplings and mandrels. Teflon coating protects plastic from adhesion to metal. Used mainly for periodic or one-time works. If the choice has stopped on this device, except its power and thermoregulation methods, it is necessary to check the stability of the structure.
• Cylindrical: semi-professional and professional units, the heating element in which has the form of a straight or lateral cylinder. Welding machine in the form of a letter "G" with a side cylinder can be used for soldering in hard-to-reach places.

The speed of the operations depends directly on the power of the device. For one-time work, it is better to purchase a medium power tool. Be guided by the diameter of the pipes. For example, if it is 40 mm, this figure is multiplied by 10, plus 20-40% of the stock is added. That is, 40 x 10 + 80 = 480 watts. Round the figure to 500 watts. For pipes of larger diameter (for example, 16-centimeter), a professional, expensive unit with a capacity of 1800-2000 W will be required.

The heating level, the information about which is displayed on the display, is set by the thermostat. The devices with electronic or microprocessor thermostats are considered more accurate, allowing to measure the temperature as accurately as possible. In capillary and bimetallic thermostats, the error in measurements increases.

Too many attachments to the building hair dryer, used in everyday life, do not need - it is enough to buy a device with nozzles 20, 25 and 32 mm in diameter. Moreover, a manual tool to weld pipes with a diameter of more than 40-60 mm is problematic. The set of the soldering iron can include additional tools: faskosnimatel, cutter, shyver for stripping reinforced plastic, calibrating device, face, etc. You can buy them separately.

Process technology

Depending on the type of connection, polypropylene pipes can be welded:

• Bell: in a similar way, pipes of small diameter (up to 40 mm) are connected in heating and water supply systems. Centering and compression are provided due to the calculated pipe dimensions and clutch or other shaped product (tee, adapter, etc.). In the usual state, the diameter of the pipe is slightly larger than the inner diameter of the coupling, after melting and applying a little physical effort, the pipe enters the coupling to a depth equal to the depth of heating, forming a strong and reliable attachment. For polymerization, a certain time is maintained.
• Butt joint: for connecting parts of the same type and equal diameter. The ends of the pipes are located on one axis, that is, the end to the end. As a result of simultaneous heating and mechanical compression of parts, polypropylene interpenetrates. To achieve this effect requires the use of special machines. In domestic conditions the method is not applied, it is used for welding thick-walled pipes of large diameter in lines.

Pipes with a diameter of 4 cm to connect manually and center very difficult. For such operations, electric coupling units with alignment devices are used. Such devices operate in automatic mode and relate to high-tech, expensive equipment.

What is the temperature of heating?

To obtain a strong bond, it is important to determine the exact heating temperature. If it deviates in one direction or another, there is a risk of plastic damage during operation and leakage. At low temperatures, the plastic will not melt sufficiently, and the fastening will be unstable. With its excess, it is excessively deformed, and because of the formation of sags, the diameter of the hole will decrease. And insert the superheated and too softened pipe into the fitting will be problematic.

The temperature of the heating element is set by a mechanical (bimetallic) or electronic thermostat. If working with polyethylene requires a temperature regime within 220 ° C (± 5), then polypropylene is welded at a higher temperature of 260 ° C. Experts advise you to immediately set the desired temperature when purchasing a welding machine and then not to change it any further. On old "soldering irons" it is not regulated at all, but such devices are quite suitable for use.

The heating time of the pipes depends on their diameter. Observe it must be exactly:

• 20 mm: heating does not take more than 6 seconds;
• 25 mm: enough for soldering 7 seconds;
• 32 mm: processing time 8 seconds;
• 40 mm: heating 12 seconds.

Modern apparatus for welding polypropylene equipped with a system of light or sound warning. It is enough just to set the desired temperature and time.

Pay attention to the temperature of the surrounding air. In cold rooms, the heating time of the soldering iron is increased by 2-3 seconds. Although it is better to select this time by experience. At an air temperature below + 5 ° C, the heating time is increased by 50%.

Despite the apparent simplicity - heated, connected, cooled - in the welding of polypropylene there are many things that should not be missed:

• In the absence of experience at first it is better to practice on a piece of pipe, because the heated polypropylene retains plasticity for a short time, during this time it is necessary to have time to unite the elements without distortions, fix them firmly and, without changing their positions, wait for complete cooling.
• Pipes and fittings of different firms, even of the same diameter, should not be welded together - due to the difference in the chemical composition, it will be impossible to achieve a reliable connection.
• To obtain a smooth cut, exactly at 90 ° only a very sharp tool is used. All burrs are carefully cleaned.
• Buy only quality plastic - when choosing products from a dubious manufacturer, the pipeline can leak.
• To work on weight it is forbidden - the iron for welding should necessarily have a support. It is more convenient if it has a fastening to the table in the form of a screw clamp.
• Since the fitting warms up a little longer, it is put on the nozzle first.
• Too slow and tighten the interval between heating and installation should not be - welding will be fragile.
• The pipe must be inserted into the fitting until it stops, otherwise it will leak in the place of the resulting gap due to the reduction in the wall thickness.
• Plastic surpluses formed during the welding process should not be removed immediately - the non-heated joint is easily deformed. Although, of course, the experienced master of the swim appears very rarely.
• Rotate, screw in the details when connecting is prohibited, the movement must be done only in a straight line.
• Excessive force when connecting is also unacceptable - as a result, a large plastic influx can form in the pipe, preventing the passage of liquid.
• The accidentally damaged fitting should be replaced with a new one, but sealing it with a pipe is inadmissible.
• Some aggregates of Chinese and Turkish production are equipped with two heating elements with separate switches. But in order to avoid the risk of overheating of polypropylene, both should not be used immediately, let the second heater be only spare.
• The cooling time should be approximately equal to the heating time. Do not shorten this period, otherwise the connection will be fragile.
• The pipe joints must not be contaminated - welding dusty and dirty products can lead to loss of strength. Additional surfaces to be welded are degreased with acetone, gasoline or white spirit. Usual vodka for these purposes is prohibited, as it is capable of loosening plastic.
• Inadmissible and moisture ingress. When accumulating in water pipes, they are filled with salt or bread crumb, they should be washed thoroughly after welding.
• For systems with hot water, polypropylene, reinforced with foil or glass fiber, is used. When cleaning foil, even a small remaining piece is sufficient to cause leakage during operation, it must be carefully removed for the entire length of the spike. Stripping of fiberglass is not required - this material solder very well.
• It is important not only the purity of the pipes, but also the soldering iron itself. After each operation, the plastic remains must be completely removed.

Cold welding

The bonding of polypropylene with a special glue (cold welding) is no less strong than fixing with a hot weld method. However, it is used only for pipes that supply cold water. Because the adhesive under the influence of high temperatures can soften.

The installation process is simple:

1. Pipes are cut precisely at an angle of 90 ° and cleaned from burrs, dust and dirt.
2. Fittings and pipes are marked in such a way that when they are connected between the fitting end and the pipe there is no gap more than 1 mm.
3. The glue is spread thinly on each of the parts.
4. They are held together.
5. The connection is fixed by hands in a fixed position for 15 seconds.
6. You can connect the water one hour after cold welding.

Repair or replacement of communications made of polymer pipes is not without the procedure such as welding. How to properly weld polypropylene pipes with your own hands and what to consider when joining the elements, we consider in the article.

One of the undeniable advantages of polymer pipes is the ease of assembly.

The installation of elements can be done almost everywhere: to lay openly on walls or to place hidden under the floor.

If welding of water pipes from polypropylene is made correctly, the assembled system will properly serve without repair for several decades

Polymer pipes are available in diameters from 20 to 110 mm. For household purposes, the most commonly used products are sizes 20/25/32/40 mm. The area from the application determines the index of the nominal pressure of the material. In the marking it is denoted by the letters "PN":

• PN 10 - is chosen for the arrangement of cold water supply.
• PN 16 - is used for cold water, but with a higher head, as well as for the installation of a "warm floor" system.
• PN 20 - products, the only limit of which is the temperature regime of the liquids transported through them. It should not exceed 75 ° C.
• PN 25 - universal products used for the arrangement of both "cold" and "hot" systems, the temperature of which reaches 90 ° C.

On sale you can find polymer products, equipped with additional reinforcement.

Armored products are used for laying on long sections in conditions where it is necessary to reduce the linear expansion that occurs when temperature fluctuations

The main feature of polymer pipes is the impossibility of their bending. Therefore, all changes in the trajectory of the laid trunk are carried out only from straight sections connected by auxiliary hardware elements:

• crossings - to enable branching of the main flow;
• tees - breeders of streams;
• couplings - for connecting pipes in a straight section;
• bends - to change the direction of the pipeline.

Fittings can be equipped with a fused metal thread, which makes it possible to connect the polymer pipeline with metal elements.

To ensure that the seams are as tight and tight as possible, it is important to ensure an exact match between the diameters of the elements to be joined

When choosing auxiliary elements, two parameters should be taken as a basis: the internal section of the products and the thickness of their walls. These parameters must comply with the technical characteristics of the polypropylene pipes used.

Methods of connecting polymer pipes

When the pipes made of polymeric materials are joined, depending on the installation conditions, one of two methods is used:

1. Soldering - involves heating and mating the molten ends of the elements.
2. Without soldering - involves joining pipes through compression fittings or by implementing so-called "cold" welding.

The second method of installation is convenient in the sense that for its implementation there is no need to use special equipment. All work can be done using a simple tool - a crimp key.

Connection Tools

The main tool used to connect plastic pipes is the iron for welding. This is a kind of soldering iron, working from the network in 220V. The principle of the device is quite simple. The role of the heating element of the iron is performed by a welding heater, placed in a metal casing. He warms up to a given temperature a plate that heats the nozzles. The temperature regulator is responsible for maintaining the optimum temperature of the nozzles.

The iron is a compact and light welding device equipped with seats for placing sleeves for pipes and mandrel for shaped products

In the kit to the iron there are heating nozzles of standard sizes. Heat up to a certain temperature, they soften propylene to a viscosity that will ensure a tight joint of the elements. The nozzles are selected depending on the diameter of the pipes used:

• The 20-th size - for pipes in diameter in half an inch;
• 25th - for products with a diameter of 0.75 inches;
• 40th - for elements measuring 1.25 inches.

Since the cost of such a welding machine is quite high, and it is not so often necessary to use it, it makes no sense to purchase equipment. The tool is better to take a day or two for rent.

For high-quality cutting and preparation of welded areas, it is best to use a special tool for this purpose - a pipe cutter. With its help you can get a smooth, smooth and beautiful cut.

The role of the cutting element of the pipe cutter is made with a stainless steel blade; For ease of use, the tool is equipped with a rubber grip

In the absence of a pipe cutter, work can be done by a Bulgarian or a hacksaw for metal. The only thing is that the fringe remains after the cutting tools. But it can not be removed easily by stripping off a strip of sandpaper.

In addition to the main tools for the work will also be required:

• gon;
• construction roulette;
• a simple pencil or marker.

When planning to join pipes by the method of "cold" welding, it is necessary to purchase in advance a thermoactive glue made on the basis of polyester or epoxy resin, or its thermoplastic analog, produced on the basis of rubber.

Basic stages of soldering technology

The key conditions for the successful installation of a plumbing system from polymers are the careful calculation of the required material and the competently welded elements.

Calculation of volumes of material and components

To simplify your work, minimizing the errors in the installation, the first thing you need to draw a scheme of the future system, indicating the number of turns and branches. When calculating the number of pipes for each length of the segment should be added to 25-40 mm, spent on "provar".

The price for polymer products and the shaped elements necessary for their installation is not large, and therefore, in the case of defective brazed pairs, which often occur at the beginning of work, it makes sense to make a small margin

If you have not yet had to weld polypropylene pipes, experienced specialists recommend that you purchase several pieces of pipes for preliminary training. Such costs and at a price will be inexpensive and will avoid major errors in the installation of the system.

A feature of polymer pipes is an increase in the coefficient of linear expansion under the influence of high temperatures. As a result: with heating or increasing pressure inside the system, the pipes become lengthened and eventually start sagging. To prevent this phenomenon, when laying sections longer than 4-5 meters, you will also need to use expansion joints.

Compensators are "P" -shaped connectors, outwardly reminiscent of wrapped hinges, which ensure the reliability of the system during its operation

Compensators are installed both on horizontal and vertical sections, mounting them between two fixed supports. If necessary, it is also possible to purchase special modification compensators, which can eliminate linear expansion at the angular folds of the pipeline.

We will find out how to properly weld polypropylene pipes, so that there are no leaks in the joints.

Soldering of pipeline components

Briefly, the essence of the technology for welding polypropylene pipes is that, under the influence of high temperature, the ends of the elements to be joined are heated and pressed tightly together to each other.

To create a strong connection when performing soldering, the pipe itself is warmed from the outside, and the auxiliary elements involved in its joining are internal

Before the beginning of the work, pieces of pipes cut off for the specified length relieve of unevenness and burrs. If a layer of internal or external foil is provided in the pipe, it must first be cleaned with a torch equipped with well sharpened and adjusted knives.

When performing stripping with the use of a face-piece, the pipe must be plunged into the tool until it stops.

The work on the welding of plastic pipes with their own hands is carried out in the following sequence:

1. Connect the soldering iron to the power supply in order to warm up the equipment to an optimum temperature of 260-270 ° C.
2. The pieces of pipe to be joined at the same time are put on the nozzles, ensuring the most even entry. This work should be done quickly and confidently.
3. After the specified time in the instructions, until the fittings and ends of the pipes melt, the elements from the heating nozzles are removed.
4. Dock the molten ends together, gently squeezing each other for 15-20 seconds.
5. The bonded parts are left in a static position so that the seam is completely cooled and the connection becomes monolithic.

Determine the duration of heating can be from the instructions attached to the equipment or using the table below.

The duration of heating to achieve complete polymerization of the joined elements depends on the diameter of the articles and the thickness of their walls

The requirements for the heating time specified in the table can not be ignored. Insufficient heating is not able to provide a reliable connection. Excessive overheating will result in the polypropylene "flowing" and the parts being deformed. As a result: protrusions are formed on the inner surface of the welded joints, which significantly reduces the diameter of the pipeline.

In order to be able to control the depth of occurrence of the segments in the heating element, thereby reducing the likelihood of a defect, it is desirable at first to make the notches

After completion of the polymerization and freezing, which takes about 20 seconds, the joint is ready. By the same technology, all subsequent nodes are soldered to the finish, until the water supply is fully assembled.

Typical installation errors

The main mistakes that novice masters allow when working with polymer products:

1. Heating of parts. At the time of heating, the parts must be in the most flat position. The slightest displacement can negatively affect the operational parameters of the entire plumbing system.
2. Adhesion of polymerized ends. While pressing the molten ends of the elements, it is not possible to rotate the parts around their axis. This can lead to the fact that the seam is not strong enough.
3. Correction of alignment. When the elements are joined, only an easy adjustment of their alignment is allowed, the duration of the procedure being not more than 1-2 seconds.

Another important point: when carrying out the soldering of the cranes, it is necessary to take into account the location of the valves, providing them with a free full stroke.

Heated polypropylene cools so quickly that already an hour after the completion of installation in the system, you can safely serve water

If, after joining the elements as a seam, doubts arise, it is better to cut the joint site and re-make it again. Elimination of defects is better performed at the stage of installation of the structure, since it is much more problematic to replace the leaky joint in the running system.

Assembly of components without soldering

The use of compression fittings and modern adhesive compositions makes it possible to perform installation of polypropylene pipes qualitatively, quickly and with minimal material investment.

By installing a compression fitting

To implement this method of connection, you will need to purchase compression fittings and use a crimping wrench.

Compression fittings are equipped with sealing clamping rings, acting as dampers in the event of shock impulse loads (unlike simple cap nuts)

Installation of the compression fitting includes three basic steps:

1. On the end of the tube cut off at a right angle and peeled off from the burrs, put on the blue nut. When placing the crimp ring of white color, it must be given such a position that the thickened part was directed towards the tail part of the pipe.
2. The pipe is inserted into the fitting until it stops, pushing the clamping ring to the maximum.
3. Twist the blue nut, "healing" it first manually, and then pressing with a key.

To assemble the compression fittings, no special knowledge and skills are required. Products are on sale fully ready for installation. Their installation can be performed under any temperature conditions.

By gluing together the elements

Adhesive method is used for the assembly of a water pipe, according to which only cold water is to be transported. To apply the method of "cold" welding, you will need to use "aggressive" adhesive type LN-915.

The glue is able to dissolve the surfaces of the assembled parts by one third, thus creating conditions for cold diffusion welding

To protect the skin of the hands from accidental ingress of the composition and "corroding" it with the active ingredients, it is better to carry out gluing manipulations in protective gloves.

Sequence of actions for gluing products:

1. Verify the correspondence of the cutting angles of the joined areas and mark the pencil with the pencil for gluing.
2. Peel and degrease the pipe ends to be joined.
3. At the ends of pipes and the area of ​​the socket of the fittings, an adhesive layer is applied uniformly.
4. The pipe cuts are inserted into the holes of the fitting, being guided by the pencil marks. The structure is held in a fixed position for three minutes, after which excess waxes are removed with a napkin.
5. The combined elements are laid out on a flat surface and left for 5-6 hours until completely dry.

Running water to check the quality of bonding can only be done a day after the installation is completed.

When implementing this method, it is important to observe two basic conditions: temperature and humidity. All work should be performed at an air temperature of +5, + 35 ° C. When gluing in hot weather conditions, work should be done as quickly as possible so that the glue does not dry before the installation is completed.

On the subtleties of the processes of soldering and gluing pipes can be learned from the following videos:

How to solder pipes:

Assembly of plumbing without soldering:

Work on the self-matching of polypropylene pipes, even with a novice master, should not cause any special difficulties. It is only necessary to perform all technological standards in a clear and conscientious manner.