Technology of welding of polypropylene pipes. How to properly solder heating and plumbing from polypropylene Appliances for welding ppr pipes

Polypropylene pipes are currently widely used for laying water pipes and pipelines.

When PPR pipes and fittings are heated on the sockets of the welding machine, local depolymerization of polypropylene occurs, and when the surfaces of the pipes being welded are tightly aligned and cooled, mutual diffusion of the material and repolymerization occur. Thus, subject to all the subtleties of welding technology, the welded surfaces of pipes and fittings become one.

Equipment for diffuse socket welding of polypropylene pipes

For work you will need:

1. Pipe cutter. The most common option is pipe shears. However, such a pipe cutter does not guarantee an even cut and may partially deform the pipe. A smoother cut is achieved when using a circular pipe cutter for plastic pipes. In the absence of a special cutting one, you can use a hacksaw with a fine tooth and a miter box.
2. Trimmer. When using pipes reinforced with metal foil in heating and hot water supply systems, to prevent delamination of pipe walls during hydraulic shocks at high temperatures, it is recommended to remove the inner foil layer for up to 2 mm. Also, the trimmer allows you to get a smooth cut chamfer and remove possible burrs.
3. Ruler and pencil. On the pipe it is necessary to measure and mark the recommended welding depth. If you do not comply with the norms for deepening pipes into fittings during welding, polypropylene rollers can form inside, narrowing the pipe clearance. Also, marks on the pipe and fittings are useful for welding pipes in a certain relative position.
4. Alcohol wipes. The place of welding of a polypropylene pipe must be thoroughly dedusted and degreased to prevent the formation of capillary passages in the thickness of the material to be welded.
5. Welding machine with interchangeable socket nozzles (mandrel couplings). For most cases, a conventional and inexpensive welding machine with a sword-shaped heating element with a power of up to 1 kW is suitable. Such a device can provide welding of pipes with a diameter of up to 63 mm. Professional welding machines are more powerful, more accurate in temperature control. Also, professional devices allow you to simultaneously heat two pairs of sockets of different diameters, so as not to waste time replacing them when welding pipes of different diameters. For welding PPR pipes in hard-to-reach places, there are welding machines with a thin round heating element, which can be located either straight or at an angle of 90 degrees. The sockets for such welding machines are made as a single unit with a hole for the heating element between the sleeve and the mandrel. When choosing a welding machine, it is important to pay attention that the sockets in the kit are coated with a Teflon non-stick coating (referred to as PTFE) to prevent plastic from sticking to the sockets. In domestic use, two heating indicator lights are sufficient: red (operating indicator) and green (indicating that the set temperature has been reached). The handle of the heating regulator must have a clear graduation and good fixation in the selected position. There will be no extra clamp on the stand of the welding machine: it allows you to fix the machine so that it does not move when the heated pipes are disconnected.

Types of polypropylene pipes

The service life of products depends on the temperature of the medium and the pressure created in them. With the right choice of the type of material, it is possible to significantly extend its operational capabilities.

There are 4 types of pipe materials that have different characteristics depending on the temperature of their operation.

PN10 brand materials refer to products intended for cold water supply. They are not able to withstand the high temperature of the environment. The second type, marked PN16, refers to products of a mixed type and is designed for cold and hot water supply, but with limited operating temperatures. PN20 and PN25 are materials intended for hot water supply. Such pipelines are able to withstand high temperatures, and products marked PN25 are additionally reinforced with metal, which increases their service life and ability to withstand high pressure and temperature conditions.

Pipe welding kit

If welding of polypropylene products has to be carried out regularly, then it is advisable to purchase a special welding kit, which is immediately sold in an appropriate suitcase. Its average cost is about one hundred dollars, and it consists of:

• heating element;
• Teflon nozzles of different sizes;
• scissors for cutting polypropylene pipes;
• bolts that are attached to the heating element of the nozzle;
• level;
• supports for the heating element;
• hexagon for tightening bolts.

In the case when welding work is carried out from time to time, it is more rational to rent welding equipment.

Types and purpose

Polypropylene pipes are available in four colors - green, grey, white and black. Only black ones differ in characteristics - they have increased resistance to ultraviolet radiation and are used when laying an irrigation system on the ground. All the rest have similar characteristics and are laid indoors or buried in the ground.

By appointment, polypropylene pipes are of the following types:

• For cold water (temperature up to +45°C). It is easy to distinguish them by the longitudinal blue stripe.
• For hot water supply (heating up to +85°C). A distinctive feature is a red stripe.

Universal (maximum heating up to +65-75°C depending on the manufacturer). Two stripes are applied side by side - blue and red.

For both cold and hot water, there are pipes with different characteristics. This is displayed in the label:

• PN10 are used exclusively in cold water supply systems (up to +45°C) with low pressure (up to 1 MPa). They have a small wall thickness. Not suitable for high rise buildings.
• PN16. They are often labeled as universal, but more often used for cold water - they withstand heating of the medium up to + 65 ° C and pressure up to 1.6 MPa.
• PN20. Thick-walled pipes, which can transport medium with temperatures up to +80°C, withstand pressures up to 2 MPa. Used in the distribution of hot water and heating systems.
• PN25. These are reinforced polypropylene pipes (foil or fiberglass). Due to the presence of a reinforcing layer, they often have a smaller wall thickness than PN20. Medium heating temperature - up to +95°C, pressure - up to 2.5 MPa. They are used for hot water supply and heating.

All of them are produced in different diameters - up to 600 mm, but in apartments and private houses they are used mainly in sizes from 16 mm to 110 mm

Please note that the inner diameter is indicated, as the wall thickness may vary.

Stage two. Welding of polypropylene pipes

This procedure will require an electric jigsaw (cutting polypropylene) and special welding equipment.

Step one.
While the apparatus is warming up, the necessary measurements are taken, the pipes are marked and cut.

Step two.
The ends of the products that are planned to be interconnected are carefully cleaned and degreased.

Step three.
Using a pencil, the depth of entry of each product into the sleeve is marked. It is characteristic that at the same time there should be at least a millimeter gap, so the pipes do not rest against the coupling of the fitting.

Step four.
A PP pipe with a fitting is put on the sleeve in accordance with the marks made, and the heating of all elements must occur simultaneously.

The duration of heating depends not only on the diameter of the products, but also on the depth of welding (this can be found in the table below).

Step five.
After a certain period of time, the products are removed and connected, with little effort, sitting on top of each other. It is forbidden to rotate the elements along the axial line.

Step six.
Within a few seconds after the connection, the primary adjustment is performed, then the elements are finally fixed.

If there are no gaps left at the junction, then it (the connection) can be considered of high quality.

Welding Machine Manufacturing

In view of the fact that a more or less good one costs over a thousand rubles, it is cheaper to rent it or make it yourself. If the latter was chosen, then for work you should prepare:

The sequence of actions should be as follows.

Step one.
In order to improve heat transfer, the sole of the iron is treated with thermal paste, then a Teflon sleeve is fixed. The location of the latter is determined in advance - the wide part up or down.

Step two.
A sharp “nose” is sawn off for more convenient work near the walls.

Step three.
The heating of the iron is carried out until the device switches off a second time.

Step four.
It is good if the iron is equipped with a temperature sensor - this will allow you to accurately determine the heating temperature. But there is an easier way - through lead. This metal melts at 230ᵒС and higher, which approximately coincides with the temperature required for welding.

Further technology is identical to that described above.

Required Tools

Polypropylene pipes themselves;

Special apparatus for welding such pipes;

Welding machine

A hacksaw for cutting them, a special cutter is often sold complete with a welding machine; for large volumes of work, you can use a ring cutter or special scissors;

Degreaser (ethyl or isobutyl alcohol); acetone in this case is forbidden to use, as it is able to soften the plastic;

Beveler: Its inside resembles a pencil sharpener, however, since the bevel must be cut evenly, the knives are located at a different angle; you can replace the beveler with an ordinary file and a knife;

Beveler for plastic pipes

Shaver: a tool for removing the reinforced layer (if our pipes have a layer of reinforcement).

Shaver

Advice.
Pipes that fit close to the heating boiler (at a distance of less than half a meter) should be made only of metal. They are connected to polypropylene using adapters from a welded joint to a threaded one.

Working with polypropylene pipes

Today's polypropylene pipe installation system includes all the necessary elements for connecting pipes of various sizes, contours, fittings, fasteners and inclusions. The assembly process is quite simple and, with the necessary skills, is fast.

The set of elements can be customized the way you want, so that the result is a completely unique system. The complexity and equipment depends only on the preferences and wishes of the customer, that is, you. The only feature that some attribute to the disadvantages of polypropylene is the welded connection method. After welding, it is no longer possible to separate the pipes and correct the error. Therefore, you need to think over everything in advance and try to avoid inaccuracies in actions.

If we break down the pipe welding process into separate steps, it will look like this:

1. With a soldering iron for polypropylene, it is necessary to heat both parts that you want to attach to each other.
2. After you need to connect the heated parts;
3. After a short period of time, remove the already fastened elements from the apparatus.

Welding provides the elements with such a strong connection that it is almost impossible to separate the parts without breaking them. That is why polypropylene pipes are considered to be of high quality, durable and able to withstand almost any pressure.

Main stages of work

1. We take a pipe of the right size.

2. We clean its edges from burrs formed during cutting with a file or beveler.

3. We mark with a pencil at the end of the pipe (see photo) which section we need to melt, that is, we outline the place where the fitting will be put on.

We outline the place of soldering with a pencil

4. We process the pipe and fitting with a degreasing compound.

5. Firmly fix the welding machine to the table.

6. Its kit includes nozzles of different diameters. We take the required nozzles (one for the fitting and one for the pipe) and fasten them on both sides of the device.

7. Set the temperature to 260°.

8. As soon as the lights go out (this means that the device has warmed up enough), you can start working. The average heating time is 2-3 minutes.

9. We put on hot nozzles (there are two of them) a fitting and a pipe to a pencil mark. Too much pressure on the parts to be welded or rotate them should not be.

Butt welding machine. Fitting and pipe are put on hot nozzles

10. We count the prescribed amount of time. The heating time is always indicated in the instructions. For example, for a 25 mm pipe it is exactly 7 seconds).

The heating time of the device depends on the diameter of the pipe

11. Quickly and accurately remove the heated parts, slightly holding the welding machine.

12. We connect them with each other. Excessive pressure on them or rotation is also unacceptable.

13. We are waiting for a few seconds.

14. If we did everything right, we get a perfectly even, homogeneous connection.

The reinforced layer on the segment of the connection must be removed, otherwise the connection will be inhomogeneous and fragile;

When buying a device, it is not necessary to spend extra money and purchase a model with a thermostat, because we need a single temperature regime of 260 ° C; using other modes may result in a poor connection;

Water must flow freely through the pipes; so that an obstacle in the form of frozen plastic does not form at the place of soldering, do not put too much pressure on the melted parts when connecting; however, low pressure is also unacceptable - the length of the connection for reliable fastening will not be enough; this can lead to the formation of turbulence and pressure drop in the system;

The basic rule of such soldering is: the fitting is put on the nozzle first, and only then the pipe; the countdown starts when both parts are on the machine;

Polypropylene seizes in 4-8 seconds, but you should not immediately release it - in order for it to completely freeze, you need to wait 20-30 seconds;

Parts during cooling must be motionless, the slightest shift can break the tightness of the connection; therefore, before soldering, it is better to prepare special clamps for fixing them; you can make them from any bar of wood or strong wire;

Cooling the resulting node with water or a jet of cold air is prohibited - the connection will be fragile;

Do not heat up the pipe and fitting more than the allotted time - polypropylene will be deformed; with less time for heating, the connection of parts will be difficult;

With proper welding, part of the plastic should form a slight influx on the sleeve;

You can check the quality of your work by cutting the connected section in half; you should see at the junction an even monolithic connection without deformations and voids.

Sewer system from PP pipes

As noted earlier, polypropylene pipes are actively used today in the arrangement. The installation procedure in this case has its own nuances.

Internal sewerage

There are a number of rules that must be observed when installing sewerage in the house.

1. The pipeline is laid at an angle in the direction of the sewer riser (about 3 cm per linear meter).
2. If the room is not heated, then the pipes are additionally insulated with mineral wool.
3. Do not make sharp turns at an angle of 90ᵒ, so-called half-bends are used instead.
4. Fan-type ventilation is a mandatory component of the sewer system, which will prevent the penetration of an unpleasant odor into the home.
5. The toilet is connected only after the sink, otherwise the water seal will break.

Outdoor sewerage

Step one.
The diameter of the pipes is determined, depending mainly on the number of people living in the house.

Step two.
A trench is dug from the sewer riser to a septic tank or cesspool. At the same time, a slope is observed, depending on the soil freezing line, or the pipeline is insulated with mineral wool.

Step three.
The bottom is covered with a "pillow" of sand. Its thickness should be at least 20 cm.

Step four.
Pipeline is being laid

It is important to avoid possible sagging, otherwise the connections will soon collapse. Horizontal drilling of a trench for the pipeline is carried out using special equipment with pressure jack pumps

Drilling takes place using a steel cone-shaped tip. Similar technology is used in the construction of:

Horizontal drilling of a trench for the pipeline is carried out using special equipment with pressure-action jack-pumps. Drilling takes place using a steel cone-shaped tip. Similar technology is used in the construction of:

• auto and railway roads;
• pipelines to basements;
• highways to working wells.

Do-it-yourself installation of a PP pipeline will help save a lot, but only if it is done correctly.

Products made of polypropylene are used, as a rule, when creating drainage and irrigation systems, as well as when laying a water pipe or arranging a heating system. Polypropylene belongs to the class of polyolefins, which means that all products made from this material are distinguished by a high degree of environmental safety.

In addition, polypropylene drainage systems can last a very long time, while the cost of their operation will be minimal. However, when working with such products, you need to know how to weld polypropylene pipes in such a way as to avoid their deformation
and prevent leakage.

DIY welding

Work should be done in a well ventilated area. Polypropylene, when heated, is capable of releasing toxic substances, and they can be harmful to health, causing poisoning.

Step by step instructions for welding:

1. First, the necessary nozzle of the correct size is installed on the soldering iron;
2. To melt polypropylene, a temperature of 260 degrees must be reached;
3. Prepare parts for connection, carry out their cleaning and proper placement;
4. Then the soldering iron is put into operation;
5. It is necessary to wait for the required time for heating, and this is indicated by the green color of the sensor.

When soldering, it is better to place the device in such a way that it stands steadily

Then the pipe and fitting are simultaneously put on the blank and the soldering tool. The pipe is inserted inside the blank. The fitting is placed on the outside. It is pushed in until it stops, and the pipe is pushed in to the finished mark. The main thing is to keep the time right.

If the tool warms up badly, then the level of diffusion will be small, and this will violate the quality of the alloy. A high temperature will lead to overheating of the parts. The optimal time depends on the diameter of the pipe and fittings.

After heating, it is important to immediately dock. The main rule of procedure is compliance with tolerability

The first few seconds allow for a correction, but no turning is allowed. At the same time, it is required not to rush and not to pull, adhering to the golden mean.

Stage three. Pipeline installation

When laying the highway you will need:

• pipes;
• tees;
• Ball Valves;
• plugs;
• adapters;
• bends;
• couplings;
• detachable connecting elements;
• threaded fittings;
• plastic clamps.

First of all, the installation of the main elements of the system (plumbing, radiators, boilers, etc.) is carried out, after which, in accordance with the drafted project, the future highway is marked. The elements of the pipeline are interconnected by means of couplings.

If we are talking about heating or hot water, then thermal expansion is taken into account. To compensate for the latter, it is desirable to use mobile connections. When installing a closed pipeline, the walls are first ditched (in appropriate places, a groove is made two pipe diameters wide).

The pipeline may only be filled with liquid after one hour has elapsed from the end of installation. A hydraulic test can be carried out only after a day.

Why polypropylene

Today, pipe manufacturers provide a huge range of products for laying water supply, sewerage or heating systems. You can purchase metal-plastic, metal, or polypropylene pipes. Today, an increasing number of consumers prefer to choose polypropylene pipes, which have a lot of advantages:

• do not corrode;
• easy to install;
• do not require constant repair;
• durable and reliable in operation;
• can be laid inside a wall or floor;
• are significantly cheaper than metal pipes.

Polypropylene pipes can be used to install heating systems, for water pipes and for sewage.

Which pipes are right for you

To choose polypropylene pipes you need to know:

• the conditions under which the pipes will be operated;
• fluid pressure in the system and its temperature;
• the required throughput of the product, which determines the working diameter.

Polypropylene pipes have a special marking depending on the purpose of the product.

• PPH
  - ventilation, cold water supply.
• PPB
  – systems of cold water supply, heating.
• PPR
  – systems of hot and cold water supply, heating.

Pipes with PPR marking
- are universal. Therefore, they are the most in demand. They are highly resistant to both high and negative temperatures.

Stage one. Drafting a project

Installation work should begin with the drafting of the future highway. An important criterion here is ergonomics, so that the number of turns and connecting elements should be kept to a minimum.

When arranging a heating system, a well-designed project is especially important, in which the location of such elements as:

• couplings;
• adapters;
• fasteners;
• corners;
• heating equipment.

The line is connected to the radiators in a one- or two-pipe way, from the side or from the bottom.

Plumbing

Here, the highway is connected to a centralized system in order to supply the necessary plumbing fixtures - a toilet bowl, sinks, a boiler, etc. There are two ways to perform wiring.

Method number 1.
Open option. Horizontal pipes are installed slightly above the floor level, and vertical pipes are installed exclusively at the corners. All this makes the pipeline less noticeable.

Method number 2.
Closed option. It is extremely difficult to perform, since it involves preliminary carrying out the most accurate calculations. Pipes (necessarily solid) are immured into the walls, and each joint should have free access.

In addition, plumbing can be:

• sequential type (the most budgetary and easiest option to implement);
• collector type (a collector is used when supplying water);
• with through sockets (little popular).

Stages of work welding process

Having measured the required length of the pipe, make a mark on it with a marker. With a pipe cutter or scissors, cut the product at an angle of 90º to the axis. The tool must be sharp enough so that the pipe does not deform.

The pipe is cut at an angle of 90º to the axis

The edge of the reinforced product must be cleaned, getting rid of the top layer and foil. Without this stage, the aluminum foil, which is part of the pipes, will come into contact with the liquid during operation. As a result, corrosion of the reinforced layer will lead to a violation of the integrity of the seam. Such a connection will leak over time.

The edge of reinforced pipes is cleaned

For non-reinforced products at the end of the pipe, the depth of welding is indicated, focusing on the length of the fitting sleeve. Another important point in preparing pipes for welding is degreasing the surface. Treatment of the junction with alcohol will provide more reliable contact of the parts.

Preparing the Welding Machine

Before welding plastic pipes, it is necessary to prepare the welding machine. The handheld device is fixed on a flat surface. Machine parts must be clean and free of defects. Clean them with a cloth soaked in alcohol. The heating elements are put on when the tool is off. A mandrel is used to fuse a fitting, a sleeve is used to fuse a pipe.

The heating time of parts for welding is determined according to the table

Then the device is connected to the network. At the same time, the indicators located on the unit body should light up. One of them signals that the device is connected to the network. The second, after reaching the required heating temperature, should go out. After the indicator goes out, it is desirable that five minutes pass and only then begin the welding process. This time depends on the ambient temperature and lasts from 10 minutes to half an hour.

What is the welding process?

After heating the apparatus, put the fitting on the mandrel, and insert the pipe into the sleeve. This is done at the same time and with little effort.

After heating the device, put the fitting on the mandrel, and insert the pipe into the sleeve

In order to know how to properly weld polypropylene pipes, it is necessary to take into account the heating time. The correct period will allow the parts to warm up to the required temperature and not melt. It depends on the diameter of the pipe.

After the required period of time, the parts are removed from the apparatus and connected. In this case, the pipe must enter the fitting strictly up to the mark. During this process, it is forbidden to rotate the parts along the axis.

In the process of connecting parts, it is prohibited to rotate products along the axis

After joining the parts, mechanical impact on the seam is not allowed until it has completely cooled down. Subject to technology, the result should be a strong and tight seam.

The article gives the necessary recommendations on how to properly weld pipes, with a detailed description of each stage. By putting these tips into practice, you can independently conduct a pipeline for water supply or heating. The main thing is to choose the right pipes and follow the process technology. Only then the polypropylene pipeline will serve for a long time and uninterruptedly.

Cast iron has not been used in modern water supply and heating systems for a long time. It was replaced by light, easy-to-install and non-corrosive plastic. Today we will talk about welding polypropylene pipes with our own hands for beginners - the main stages of this process and its intricacies.

Why polypropylene is better for welding than metal

A variety of elbows and fittings, as well as profile and round bends made of polypropylene, are deservedly popular because:

• After properly welded, they form monolithic parts that can last more than fifty years.

Having appeared relatively recently, polypropylene pipes immediately won the sympathy of plumbers and ordinary people. Eco-friendly, high-quality material implies a long service life, and proper installation ensures reliable tightness of the joints. Equally important is the versatility of such pipes. They are used in water supply, various irrigation and drainage systems. You can use them for heating systems. The main thing is to know how to weld polypropylene pipes as correctly and reliably as possible. This will require information about these modern products.

Advantages of polypropylene pipes

• The type of material allows pipes to have high resistance to chemicals, and also does not accumulate dirt inside the pipe.
• The price of pipes, fittings and other components required for installation is significantly lower than similar plastic materials.

In the vast majority, all the shortcomings that arise during installation are associated with non-compliance with the technological process and the wrong selection of fittings and taps.

Which pipes are right for you?

In order for a heating or water supply system made of polypropylene pipes to be reliable for a long time, you need to choose them correctly.

• To do this, you need to know the operating conditions
• The required capacity of the pipe or its diameter
• Operating conditions
• The temperature of the liquid and its pressure.

Knowing these parameters, you need to select the appropriate brand of pipes:

• PPH - for cold water supply and ventilation
• PPB - for heating and hot water supply
• PPR - for heating and systems of cold and hot water supply.

The last type of polypropylene pipes is universal. High operational characteristics allow to apply for the widest use.

Tools You'll Need

In addition to, in fact, consumables (pipes, taps, fittings) for installation, you will need a set of appropriate tools:

1. Welding machine
2. Pipe cutter or scissors
3. Nozzles for the apparatus of various diameters
4. Roulette
5. Marker

How to prepare pipes

Having measured the desired section of the pipe, a mark is made with a marker. Then, with a pipe cutter or scissors, which should be placed strictly perpendicular to the pipe being cut, the desired part of the product is cut off.

Particular attention should be paid to the quality and sharpness of the cutting tool. If it is not sharp enough, then instead of cutting, you will crush the pipe.

Since there is an aluminum layer in the reinforced pipe, it is necessary to get rid of it. The fact is that over time, aluminum foil will begin to break down from contact with water. To do this, use a stripper to remove the top and foil layers.

For elements without a reinforcing aluminum layer, note the depth of welding at the end of the pipe, depending on the length of the couplings.

Then degrease the welding points with alcohol-containing liquids. This will make the connection more reliable and durable.

In this case, you should carefully examine the surface of the welded pipes. Any, the smallest particle that gets into the seam, can spoil not only this joint, but the entire system.

Preparing the Welding Machine

The pipe welding machine requires some preparation before installation. You need to choose a flat, smooth surface and install the device on it. All parts of the welding unit must be dry and clean. If necessary, they are wiped with alcohol. Heating elements must be installed when the machine is switched off.

When the welding machine is connected to the mains, the indicators on the body light up. One indicator is designed to control the heating temperature. It should go out when the heating reaches the required value. It is recommended that after the light goes out, wait 5 minutes, and then start welding the products. The second indicator is a control indicator, it indicates that the device is connected to the network.

A sleeve is used to heat the pipe itself, a mandrel is provided to heat the fittings.

What is the cooking process

After the apparatus has warmed up, the elements to be welded are placed in the designated places. This operation must be performed simultaneously and apply certain efforts.

When the parts (pipe and fitting) are installed on the welding machine, the heating time begins. The correct time interval ensures optimum melting of the material and the reliability of the seam. The absolute heating time depends on the diameter of the pipe, which you can see in the table above.

Then the heated parts are removed from the apparatus and joined. Pre-made marks will help connect the parts correctly. Twisting and rotating elements is strictly prohibited. This will break the joint. In addition, you need to make sure that no sagging has appeared in the heated parts.

Now it is worth carefully setting the welded element aside until it cools completely. If you did everything as expected, then you should get a reliable and tight connection.

We insert the pipe, but pay attention then you can not scroll the pipe.

Video - soldering polypropylene pipes

Related articles:

In the process of repair, the old pipeline is increasingly being replaced with polypropylene pipes. This is due to their wear resistance, long service life and resistance to corrosion. Simplicity and ease of installation makes it possible to replace plumbing, heating or sewerage with your own hands. It is enough to have a special welding machine, a set of fittings and the pipes themselves.

How to weld polypropylene pipes with your own hands

The technology for welding polypropylene pipes is called coupling, or socket. The pipes are connected not butt-to-butt, but with the help of fittings - additional conductors, which solder the edges of the pipes at a temperature of 260 degrees.

Cutting and processing plastic pipe

When installing a plastic pipeline, it becomes necessary to cut polypropylene pipes in the middle or from the ends in order to fit them in size and dock with each other. There are several ways to cut - each requires a separate tool:

1. Battery-type pipe cutter - is a scissors equipped with an electric drive. High cutting speed is their main advantage. For each pipe you will spend about 5 seconds. Minus - restrictions in the diameter of the cut workpiece.
2. Roller-type pipe cutter - the principle of operation of the tool resembles the operation of a seaming key for preservation. The cut with the tool is smooth, without torn edges. They make several turns around the pipe, then twist the hard alloy roller and turn it several more times. Minus - the impossibility of application if the pipe is adjacent to the wall and cannot be removed.
3. Professional scissors for cutting plastic pipes - consist of an upper sharp knife and a lower holder. Using the device is easy - marking the desired length on the pipe, put it between the blades and cut it off. The edge will be smooth, without crumbs and scraps.
4. An electric jigsaw is a convenient way, but it can give a slight bevel, so the tube is cut by turning it several times.
5. A grinder of any power - cut the plastic without exerting strong pressure, use a metal disc.

After trimming, the end of the polypropylene pipe is treated with a sandpaper to remove all possible burrs and hooks.

How to prepare the welding machine

1. The welding machine must be installed on a special stand - a clamp.
2. Make sure that the contact surfaces of the device are free of dirt. If extra particles or dust have stuck to them, clean the Teflon layer with a coarse cloth soaked in alcohol.
3. Set the temperature sensor to 260 degrees.
4. Connect the welding machine to the mains and press the power button.
5. Heating occurs in no more than 15 minutes, depending on the ambient temperature.

Soldering temperature and heating time of parts. table

After cutting and marking the pipes are ready for welding. You can proceed to the next step - heating the parts.

Pipe diameter, mm	Heating time, s	Welding time, s	Waiting time, min.
16	5	4	3
20	5	4	3
25	7	4	3
32	8	4	4
40	12	6	4
50	18	6	5
63	24	6	6
75	30	8	8
90	40	8	8
110	50	10	10
160	80	15	15

Instructions "How to cook plastic pipes"

At the beginning of work, decide where the pipeline will be installed. Make a plan in advance to avoid welding knots in weight or in hard-to-reach places. It is much easier to assemble a structure from polypropylene pipes on a table, so that later, without much effort, fix it in the allotted place.

1. Turn on the device and warm it up to the recommended temperature. If you use it for the first time - after heating, wait another 5 minutes before starting the work process.
2. Insert the fitting and the end of the plastic pipe into the welding nozzle at the same time. They must be placed in the same plane. Given the diameter of the pipe, add the temperature and keep the time indicated in the table.
3. When the elements are heated, they are removed from the welding machine and instantly connected. Then hold motionless for the recommended time.
4. Immediately after cooling, the pipeline can be used for its intended purpose.

After soldering, the knot is checked for patency by blowing it with air or letting water through it.

Video lesson "Soldering polypropylene pipes"

Welding technology of PVC polypropylene pipes

Working with polypropylene pipes requires compliance with some recommendations. A properly installed connection is tight and can withstand high pressure.

Welding at negative temperatures

It is difficult to get a good welding quality at low temperatures. Manufacturers of polypropylene pipes do not recommend welding at air temperatures below +5 degrees. At temperatures below 0, the plastic becomes brittle, the soldering may be leaky. This will lead to leaks or rupture of the pipeline. In the cold season, the place where welding is carried out is warmed up - a tent with a heat gun is set up.

Is it possible to cook products from different manufacturers?

Manufacturers of plastic pipes emphasize that polypropylene products of different brands cannot be soldered. Pipes and fittings of different production may differ in several ways:

• diameter tolerance;
• softening speed;
• color shades.

An attempt to combine materials with different technical characteristics leads to difficulties in installation and causes the marriage of the entire structure.

Butt welding of large diameter products

When laying highways, plastic pipes of large diameter (from 63 mm) are welded butt-to-butt. This method is based on heating and melting the ends of the pipes, and their subsequent connection with sufficient force.

It is important that the ends of the blanks are perfectly even. This makes it possible to obtain a solder joint of maximum strength, one-piece and capable of working under high pressure.

Socket soldering fitting-pipeline connections

Polypropylene pipes with a diameter of up to 40 cm are welded with a special manual type device. It consists of a centering device and nozzles for fixing workpieces. The ends of the cut section of the pipe are cleaned with a file or sanding paper. The apparatus is heated, the details of the future pipeline are driven into it and soldered. All movements are done quickly and clearly, until the material is heated to the desired state.

Please note that with socket or socket soldering, the outer diameter of the pipe must be greater than the inner diameter of the unheated fitting.

After welding, they withstand the time allotted for cooling, do not move or turn the elements over to avoid deformation.

How to cook reinforced pipes (plus video instruction)

Reinforced pipes are used in heating systems, laying "warm floor" and hot water supply. Before starting work with the participation of reinforced polypropylene pipes, it is prepared - the aluminum layer is cleaned with a shaver. This is necessary so that during operation, in contact with water, the aluminum foil does not collapse and the structure does not leak.

The fitting is sized to fit the pipe without top layers.

Welding plastic pipes with an industrial hairdryer

An industrial hair dryer for welding polypropylene pipes is used in several cases:

• for connecting two pipe sections;
• for the manufacture of shaped parts;
• for mounting an elbow from individual elements.

When soldering plastic, a building hair dryer is equipped with a reflector - a nozzle with a special coating, to which molten material will not stick.

Having installed the hair dryer on the surface of the table, set it to the minimum air flow. The nozzle is heated to a certain temperature and the ends of both plastic blanks are pressed against it. Immediately after the softening of the polypropylene, the pipes are connected to each other.

In this position, the combined parts are held for up to 30 seconds. This time is enough for them to stick together and harden.

As a result of welding with a building hair dryer, the connection is strong and reliable.

Welding pipes in an inconvenient place

It is much easier to braze pipes on straight pipe runs than in hard-to-reach places. In order to avoid unpleasant moments during the installation of the piping system, it is best to assemble it on the surface of the table. There are cases when you need to solder pipes in an inconvenient place - near the battery, under the ceiling, against the wall or at the corners. With self-assembly, one more pair of hands is indispensable.

You can start welding the node on weight when all the elements of the pipeline are assembled. Usually it is required when connecting structural elements to batteries, water supply inlets. Here you definitely need an assistant who will hold the welding machine while you connect the parts. If the partner has certain skills, you can perform manipulations in turn.

Yulia Petrichenko, expert

All movements must be accurate and fast, and if the slightest distortion appears, replace the element. It is important to maintain a constant temperature, overheating of plastic pipes when connected in places with limited access leads to their loss of shape and problems with further installation.

Video "How to cook polypropylene pipes in hard-to-reach places"

The nuances of soldering polymer pipes do it yourself

There are many points that should be considered when working with polypropylene pipes. Failure to comply with them leads to a decrease in the quality of the connection of fittings and tubes, leakage and blockage of the system.

8 mistakes when welding plastic pipes

1. Deviation from the rules for the installation of products. If the pipe is not fully inserted into the fitting and a gap forms between their walls, then the usual loads for such a connection may be too high, which will inevitably lead to leaks.
2. Strong pressure when connecting elements. When introducing the molten end of the pipe into the fitting, the pressure should be minimal. The applied excessive force leads to the formation of plastic flow inside the pipe, its blockage or reduced patency.
3. Incorrectly selected material. The construction of low quality plastic pipes, even with skillful installation, will be short-lived. Purchase polypropylene products only from trusted suppliers and a good brand.
4. Connecting pipes from different manufacturers. Regardless of the quality of plastic pipes, it is impossible to connect elements made by different manufacturers.
5. Removal of splashes during the welding process. It is not recommended to do this - any movement before the plastic hardens will lead to even greater deformation.
6. Slow pace of work. After heating, polypropylene cools down in a matter of seconds, so it is very important not to be distracted and to connect the parts with precise movements in the allotted time.
7. Dirty welding machine. Before starting work, the Teflon surface of the device must be checked and, if necessary, cleaned of adhering plastic residues or dirt.
8. The rest of the liquid in the pipe. Water must not be allowed to enter the pipe, when heated, the drops will turn into steam, and the connection will lose strength.

When working with polypropylene pipes, remember that the heated material has a very high temperature. Take precautions: wear a robe and thick gloves to protect your skin in case of contact with hot plastic.

Not a single repair and construction is complete without the installation of plastic pipelines. Perform all work according to the instructions and polypropylene pipes will serve for a long time and reliably.

How do you install PPR pipes? Looking forward to your advice in the comments.

Do-it-yourself installation of polypropylene pipes is a feasible task for anyone who has the slightest skill in physical work.

The high reliability of welded joints allows for concealed installation of pipelines - with embedding in the building structure. This creates additional advantages in terms of room design.

Some general rules for welding plastic pipes

There are two ways to connect plastic pipes - socket and butt. Regardless of the connection method, when welding polypropylene pipes, it is necessary to adhere to certain rules, without which the high strength of the seam cannot be guaranteed.

Only thermoplastics of the same chemical composition can weld well, i.e. type 3 PP pipes must be connected to type 3 PP pipes and fittings. In this case, when heated to a certain temperature, the products have the same fluidity, ensuring a quality connection. Provided the same brand of pipes, their color does not matter. It is determined by a very small amount of chemically neutral pigment that does not affect weldability.

The pipe parts to be welded and the tool must be clean. The presence of oil and grease on the surface of parts has a particularly negative effect on the quality of the connection. They must be removed with alcohol, acetone or other solvents. Tools should be cleaned with alcohol. The rags used for these purposes should not leave fibers.

The outer layer of the polymer, which has undergone destruction under the action of ultraviolet radiation and air oxygen, can also be attributed to pollution. It can only be removed by mechanical cleaning. Sometimes moisture can condense on the surface of the pipes, which also poses a danger to the connection. Before welding, it must be removed by drying.

There is no need to try to speed up the cooling of the joint with water or cold air. Rapid cooling of the seam can lead to stresses that reduce its strength. If welding of polypropylene pipes occurs at low ambient temperatures, it is necessary to slow down the cooling by covering the seam with a cloth or heat insulator.

Socket welding of plastic pipes is the main method of connection when installing pipelines for various purposes in houses and apartments, since it is intended mainly for connecting pipes of small diameters.

For welding polypropylene pipes, fittings (corners, tees, bends) are used from the same material as the pipes themselves. The use of additional fittings cannot be considered as a disadvantage of the method, since, simultaneously with the connecting function, they also play the role of elements that provide a change in the direction of pipelines.

Schematically, the socket welding process is a melting of the mating surfaces (the outer surface of the pipe and the inner surface of the fitting) using a special heating tool, assembling the heated parts (inserting the pipe into the fitting) and leaving them in this position until cooled.

A socket joint is more reliable than a butt weld. The very nature of the connection (the pipe is inserted into the fitting) ensures its increased strength, does not require a tool for pipe alignment and does not place high demands on the user's practical skills. Do-it-yourself welding of polypropylene pipes is feasible not only for any man, but also for many women.

Socket welding equipment. Apparatus for welding polypropylene pipes into a socket, also called soldering irons or irons, are devices, the main part of which is a heating head, on which replaceable elements are fixed - couplings and mandrels. The former serve to heat the outer surfaces of the pipes, the latter heat the inner surfaces of the fittings.

The heater itself most often has the shape of a triangular plate, although there are other types of execution. The dimensions of the plate determine the size of the nozzles (the diameter of the pipes that can be welded) and the number of heating pairs that can be installed at the same time. The larger the area of ​​the plate, the more powerful the device.

When fastening, couplings and mandrels must be placed in such a way that their contact with the plate is ensured by the entire supporting surface.

As for the power of the soldering iron, if the sleeve and the mandrel are in contact with the plate over the entire area, then the required temperature of the heating pair of 260 ° C will be reached in any case - regardless of the power of the soldering iron (within reasonable limits). It's just that a less powerful device will take longer to reach the operating mode than a more powerful one.

There are models of soldering irons in which the heating head has the shape of a rod. Their main advantage is compactness. As for the technical parameters, the shape of the head does not have a special effect on them.

The type of temperature sensor used is important. The more accurate its work and the smaller the range of temperature fluctuations, the better the soldering iron. The most advanced are electronic thermostats, which are thermistors capable of measuring temperature not only very accurately, but also close to the working surfaces of mandrel and couplings. Their use allows reducing the temperature inertia of the device, bringing the actual temperature of the heating pair closer to that displayed on the scale of the device. Capillary thermostats, and even more so bimetallic relays, work more roughly. The adjustment range and the discrepancy between the actual temperature of the mandrel and coupling and the one set on the instrument scale are much higher than those of thermistors.

However, regardless of the thermostat used, after the device enters the operating mode (according to the indicator), you need to give it a few more minutes so that the temperature of the nozzles finally equals the one shown by the device. And only after that get to work.

You can find soldering irons with two heating elements of different power, equipped with hotel switches. Moreover, the power of each heater provides the required temperature regime alone. This allows you to choose the optimal power, or use the second heating element as a backup in case the first burns out. The heaters can also be turned on simultaneously for forced access to the operating mode.

In addition to a set of mandrels and couplings, a set of equipment for welding polypropylene pipes may include various auxiliary tools and materials - a beveler, calibrator, trimmer, pipe shears, cleaning fluid, etc. Not all of them are included in the basic package, some are offered as an option.

The equipment of the welding machine with a tool for preparatory operations is no less important than the technical parameters of the soldering iron itself. It is desirable to have as complete a set as possible, this will make it possible to work with any pipe, regardless of its size and the nature of the reinforcement.

Socket welding technology

The outer diameter of the pipe is slightly larger than the nominal diameter, and the inner diameter of the fitting is slightly smaller than the nominal diameter of the pipeline. For example, a pipe with a diameter of 20 mm actually has an outer diameter of 20.3-20.5 mm, and a fitting for a pipeline with a diameter of 20 mm has an inner diameter of 19.5-19.7 mm. In this case, the diameters of the working surfaces of the couplings and mandrels in their middle part (the working surfaces are conical, the taper is about 0.5 °) correspond to the nominal diameter.

Thus, a pipe and a fitting without heating cannot be combined either with a coupling and a mandrel, or with each other.

In the process of matching the pipe with the heated sleeve, the outer layer of the pipe is melted and squeezed out in the form of a bead (bead), and the inner layers are heated enough to compress elastically and allow the pipe to enter the heated sleeve. A similar effect is observed when the fitting is combined with a heated mandrel. When connecting after heating the pipe and fitting, the pipe is elastically compressed, and the fitting is elastically stretched. As a result, the heated surfaces to be welded press against each other, displacing air and mixing the molten material.

The technology for welding polypropylene pipes into a socket consists in performing the following operations: cutting the pipe, preparing parts for welding, installing and putting the welding machine into operation, setting the parts for heating, assembling the joint and cooling it.

Without great effort to combine the pipe and fitting manually with a heated tool, and then to combine the pipe with the fitting into the connection, it is possible only when welding pipelines of small diameters - up to 40-50 mm. For welding pipes with a diameter greater than 50 mm, it is better to use special centralizers for socket welding.

Pipe cutting. Pipe cutting is carried out with special scissors, which exclude the collapse of its wall.

Preparing pipes and fittings for welding. Standard preparation consists of cleaning and degreasing the outer surface of the pipe and the inner surface of the fitting. However, in addition to the standard, there is also special training performed in relation to reinforced pipes - but not all, but only some of them. Those who install polypropylene pipes with their own hands need to be aware of the features of preparing pipes with different reinforcement.

Thanks to composite PP pipes with aluminum or fiberglass reinforcement, high thermal stability of the pipeline is achieved (low thermal expansion), which eliminates the need to install temperature compensators in heating and hot water systems. Reinforcement with aluminum, in addition, eliminates the diffusion of oxygen into the system. Oxygen penetrated through the wall of the pipe saturates the water closed high temperature systems gas that causes cavitation in valves, pumps and other pipeline elements.

Pipes without a reinforcing layer or reinforced with fiberglass do not require any special preparation.

Pipes reinforced with aluminum located close to the surface (under a thin decorative layer of polypropylene) require the removal of the reinforcing layer with a special tool - a shaver. When welding PP pipes, this layer must be removed to ensure a strong and inseparable connection between the pipe and the fitting.

Pipes in which the aluminum reinforcing layer is located in the middle of the wall must be subjected to a trimming operation with a special tool, the purpose of which is to remove the aluminum edge that extends to the end of the pipe. If this is not done, water can penetrate through the open reinforcing layer into the middle of the wall and cause it to swell..

Below are photos of cuts of joints made without trimming (wrong) and with trimming (correct).

The best result is achieved with the use of special couplings. Their design ensures that the edge of the reinforcing layer is enveloped with polypropylene (its walling up), as a result of which its contact with water is excluded.

Sometimes pipe manufacturers give recommendations when preparing a pipe for welding, regardless of the presence of a reinforcing layer, to calibrate it according to the outer diameter and chamfer. The necessity of the first is explained by the possible ellipticity of the pipe, which must be eliminated by calibration. Chamfering is designed to facilitate the installation of the pipe into the coupling. However, in most cases, when welding polypropylene pipes with your own hands, neither the first nor the second is done, considering these operations unnecessary.

Preparation of the welding machine ("soldering iron"). Before starting work, the "soldering iron" for welding polypropylene pipes must be securely fixed in the bracket or on the frame. During installation for heating, certain efforts are applied to the parts, which are transmitted to the soldering iron. For the convenience of work, it is necessary that it be firmly fixed and motionless.

After installing the device, a suitable heating pair (mandrel and coupling) is fixed on its heater, the required value of the heating temperature is set using the toggle switch, and the device is connected to the network. The temperature of the socket welding tool for polypropylene pipes should be 260±10°C. This significantly exceeds the viscosity of polypropylene and is done in order to quickly melt the surface layer of the pipe and fitting and remove parts, preventing their walls from heating to full thickness. Otherwise, the pipe and fitting will lose their rigidity and cannot be connected.

Installing parts for heating. After the machine for welding polypropylene pipes enters the operating mode (which should be signaled by the indication of the device), the pipe and fitting are simultaneously installed for heating - the pipe is inserted into the sleeve, the fitting is put on the mandrel. If the simultaneous installation of parts is not possible, the fitting is installed first, as it is more massive.

Pipes and fittings have material for an allowance, which is squeezed out during the installation of parts, forming a burr - a roller in the form of a ring. Its shift requires the application of a certain force. However, the effort should not be excessive, you need to push the details gradually, making sure that the resulting burr is of the correct shape. If the fitting is put on the mandrel freely, without effort and burr formation, then it is defective and cannot be used.

When installing the parts, you need to control the depth of their installation in order to relieve the force when they rest against the bottom of the coupling and the top of the mandrel. Otherwise, you may crush the pipe end and fitting stop. To control the depth of immersion of the pipe into the coupling, a mark can be made on it at the required distance from the end. But most often this is not done, the pipe and fitting are simply installed on the mandrel until they rest.

After installing the parts in the coupling and on the mandrel of the apparatus for welding plastic pipes, you need to give them time to melt the surfaces. Heating time is a very important parameter. It should be sufficient for the surfaces to heat up to a viscous state, but not be higher than the value beyond which the parts begin to lose rigidity. Manufacturers of plastic pipes have tables that set the heating time depending on the brand of polypropylene, pipe diameter and wall thickness. Guide values ​​for the duration of heating for the pipe PPRC (PP type3) PN20 are shown in the table below.

Pipe diameter, mm	16	20	25	32	40	50	75	110
Heating time, sec.	5	5	7	8	12	18	30	50
Repositioning time*, sec.	4	4	4	6	6	6	8	10
Fixation time**, sec.	6	6	10	10	20	20	30	50
Complete cooling time***, min.	2	2	2	4	4	4	6	8

* - time for removing heated parts and connecting them.
** - retention time of the compound until partial cooling. This time is used to align the connection by hand. After this time, the connection loses elasticity, it is no longer possible to change its shape.
*** - There is no need to hold the parts until they cool completely. Enough not to create a burden. After this time, the connection is ready.

The heating time is counted from the moment the parts reach the stops. After it ends, the pipe and fitting are removed from the mandrels with the same moderate force.

Assembly of parts. The parts removed from the mandrels of irons for welding polypropylene pipes are immediately connected to each other (the pipe is inserted into the fitting). The time that elapses from the moment the parts are removed to the moment they are assembled should be as short as possible and in any case not exceed 4-6 seconds. Delay is fraught with cooling of parts and the impossibility of their assembly, or at least poor quality of the connection.

When connecting pipes with fittings, do not rotate them relative to each other by more than 5 °. The correctness of the connection must be controlled by the type of burr formed, which must be the same in thickness from all sides.

Connection cooling. After connecting the parts and (if necessary) straightening them, which takes only a few seconds according to the technology, no effort should be applied to the parts until the polypropylene has completely hardened. This usually takes 2-4 minutes.

Approximate values ​​for the duration of all operations during welding, for a PPRC pipe (PP type 3) PN20, are indicated in the table above. The exact values ​​of the parameters are reported by the manufacturers of pipes and fittings.

Typical errors in socket welding

A properly made connection is a monolithic assembly consisting of a fitting and a pipe, which is not only not inferior in strength to the whole pipe, but even surpasses it.

Various welding errors can break the integrity of the connection and lead to loss of tightness or create a weak point in the pipeline, which can collapse with a short-term increase in pressure. These errors may be as follows.

Failure to bring the pipe and fitting to the stop when installing them for heating. This leads to the impossibility of assembling the parts to the full depth (the parts rest against the burr before reaching the end) and the appearance of a weak spot in the connection.

Exceeding the normal depth of immersion of the pipe into the coupling when it is installed for heating- due to excessive application of force and / or untimely removal of it. In this case, the end of the pipe is bent inward, forming a burr, which narrows the passage of the pipe and prevents the free flow of water.

Not bringing the parts to the stops when assembling them(connection is not full depth). The consequence of this is a weak point in the connection.

Overheating of parts due to the heating time being exceeded or the temperature of the soldering iron being too high. This error leads to the loss of rigidity of the parts and the impossibility of their assembly, or deformations and folds in the connection, if the parts still managed to be assembled. The latter, in addition to weakening the structure, can lead to loss of tightness.

Underheating of parts due to the short heating time or low temperature of the welding machine. The consequence of this error is the impossibility of assembling parts or non-fusion in the joint and loss of tightness.

Exceeding the time interval between the removal of parts from warm-up and their assembly. As a result, the heated surfaces are cooled to a temperature below the viscosity. An error leads to the impossibility of assembling parts or non-fusion in a joint with a violation of tightness.

Incorrect pipe cutting, which is expressed in the non-perpendicularity of its end face to the axis. In this case, a weak point is formed in the assembled connection due to the loose fit of the end of the pipe to the internal limiter of the fitting.

Pipe and fitting misalignment during assembly. Leads to deformation and, possibly, loss of tightness of the connection.

Welding errors that do not cause loss of tightness may not manifest themselves in any way during long-term operation, however, they carry the potential threat of failure of the connections during short-term pressure increases.

Butt welding of polypropylene pipes

Butt welding of plastic pipes consists in heating their ends with a heated tool (welding mirror) until they melt, and then compressing them with pressure holding until the seam cools. This method is technologically simple, does not require additional fittings, and, if the technology is strictly observed, ensures the strength of the welded joint not lower than the strength of the pipe itself. Schematically, the process of forming a butt weld is as follows.

Butt welding of plastic pipes

However, despite the simplicity of the technological scheme, the practical implementation of butt welding is associated with some difficulties that limit its use at home.

It is necessary to ensure the exact axial alignment of the pipes and their parallelism relative to each other (mismatch of the pipe walls is allowed up to 10% of their thickness). For a certain time, it is necessary to apply a force that presses the pipes against the heating mirror during heating, and against each other during the formation of the connection. When cutting or trimming a pipe, the end face must be perpendicular. All these conditions are difficult to meet without special equipment - a centralizer equipped with a manual or electric drive that creates a compressive force, and a trimmer. That is, in the case of pipes of small diameters, equipment and tools for butt welding of polypropylene pipes are required more than for socket welding. And when you consider that socket welding provides higher reliability due to the locking nature of the connection, it becomes clear why it is preferred over butt welding when installing domestic plumbing and heating systems.

Butt welding of polypropylene pipes is mainly used as an industrial method of joining large diameter pipes when laying straight sections of pipelines (the process of butt welding of plastic pipes is described in more detail in the article Welding of polyethylene pipes).

Installation of polypropylene pipes

In the case of designing and installing a hot water pipeline and especially a heating system, it is important to take into account the thermal expansion of pipes. At the same time, the thermal expansion of various polypropylene pipes varies greatly. For reinforced pipes, the thermal expansion is much less than for non-reinforced polypropylene pipes. It is no coincidence that the developers of reinforced polypropylene pipes call such pipes "stable". By this is meant a small change in the original length of the pipe when it is heated or cooled.

On the example of polypropylene pipes of the KAN-therm PP system, it can be seen that with a maximum temperature difference of 80 °, one meter of a homogeneous pipe is extended by 12 mm, and a combined pipe by 2 mm, with a significant length of pipeline sections (more than 2-3 meters) thermal elongation when heated , or contraction on cooling, can lead to unacceptably high stresses at the joints. It should be noted that it is thermal stresses from elongation or compression, and not internal ones from water pressure, that are most dangerous for polypropylene pipes, especially in the case of homogeneous polypropylene pipes. To compensate for elongations (when necessary), they resort to various bends of the pipeline and non-rigid fastening to supports, which ensures axial movement of the pipe.

Video:

When using the content of this site, you need to put active links to this site, visible to users and search robots.