The price of pipes and fittings made of polypropylene (abbreviated as PPR) is noticeably lower than other polymers - metal-plastic, cross-linked polyethylene. But you can save twice - buy an inexpensive soldering iron and solder plumbing or heating from PPR with your own hands.
The essence of the problem: many instructions and videos on connecting pipelines have been published on the Internet, in isolation from real conditions installation The homeowner learns how to properly weld shaped elements on a table, but does not know the intricacies of laying and joining finished sections. We propose to change the approach - soldering polypropylene pipes and installation work must be mastered simultaneously.
Stages of installation work
The low cost of polypropylene systems is more than offset by the complexity of welding PPR products. It is only more difficult to install plumbing fixtures made of steel and copper pipes which need to be cooked with a gas burner. Wiring with metal-plastic and polyethylene materials is easier, but more expensive.
To reliably and beautifully solder water supply and heating pipelines made of polypropylene, we recommend working in the following sequence:
- Draw a plumbing and heating diagram, transfer the projections of the mains to the walls of the premises.
- Prepare necessary tools and devices. It is better to rent a professional welding machine (also known as a soldering iron or “iron”) with a set of attachments rather than buy it.
- Cut the workpieces and weld sections of the system in convenient conditions - on the table.
- Secure the finished sections in place and connect them together. Connect plumbing and heating fixtures.
Note. Drawing up a diagram and marking routes on the walls will allow you to clearly select components - tees, bends, couplings and determine the number of pipes to purchase.
Drawing a wiring diagram
At the stage of laying pipelines and connecting plumbing equipment, you need to have a heating and water supply project on hand. If the wiring diagram has not yet been developed and the diameters of the mains have not been determined, we recommend that you first read the manual for the private house.
Example single pipe system heating a one-story house Before purchasing and welding polypropylene elements, transfer the diagram to real conditions:
- Mark the contours of the radiators or install all heating devices in advance.
- Using a pencil or marker, mark the installation points of water outlets, taps, distribution manifolds and other fittings on the inner surfaces of the walls.
- Using a long strip and a building level, connect the marked points with lines, then lay plastic pipes along them.
- Based on the number of branches and turns of pipelines, find out the need for fittings - tees, couplings and bends.
An important nuance. Mud collectors must be placed in the correct position - horizontally, with the “nose” down. Choose suitable straight areas for installing water filters.
After drawing the projections on the walls, it is easy to calculate how many polypropylene pipes are needed; just measure the length of the lines with a tape measure. Don't forget about the plastic clips for attaching the pipework.
Markings on the wall help you see real contours future system
When purchasing fittings and pipes, take note of a number of recommendations:
- soldering of plastic pipes is carried out by immersing each end inside the shaped element to a depth of 14-22 mm (depending on the diameter), which means that the length of each straight section increases by 3-5 cm;
- in heating and hot water systems, polypropylene expands due to heating, therefore, in order to avoid bending of the lines, you need to purchase special fittings - compensation loops;
- to cross other pipelines, use bypass elements made from PPR;
- For hot water supply and coolant supply, take pipes reinforced with aluminum foil, basalt or fiberglass.
Compensation loops are installed on long lines or risers fixed with fixed supports (for example, a jumper between 2 metal pipes neighboring apartments). Without compensation for elongation, the PPR pipe will saber bend in both cases due to heat.
Useful advice. If you are planning to weld polypropylene for the first time, buy an extra 2-3 meters of pipe and several spare couplings. Straight connectors make it easier to control the quality of the joints, so practice and solder a few joints.
Soldering iron for polypropylene and other tools
Small-sized welding machines are designed for joining polypropylene with dimensions of 20-63 mm (external). Larger diameter pipelines are used extremely rarely in home communications. A soldering iron for polypropylene pipes of any design is suitable for you - with a round or flat wide mandrel in the form of an iron.
Types of welding machines and Teflon nozzles Reference. The easiest way is to rent a heater with a set of attachments. Rental cost per day is from 4 to 8 USD. e. depending on the region of residence and the original price of the device.
In addition to the soldering iron, to mark and weld PPR pipes you will need a set of tools and accessories:
- stopwatch;
- scissors for cutting are a must, hacksaws and grinders are not suitable;
- shaver - a device for trimming pipes reinforced with aluminum;
- measuring instruments – tape measure, square, ruler;
- marker or simple pencil;
- degreasing composition - white spirit, galosh gasoline, nefras, alcohol (acetone is not suitable);
- rags;
- protective gloves.
Listed here are the tools required specifically for soldering PPR pipes. To attach the wiring to the walls and connect to the batteries, you will need a set of wrenches, a drill, a hammer and screwdrivers.
All welding machines have an unpleasant feature - the soldering iron dangles in the socket of the stand and moves freely along with it on the table. Advice from an experienced craftsman: attach the stand to the tabletop with two self-tapping screws, and secure the heater with a screw, as shown in the photo.
Soldering the first joint
The technology for welding polypropylene looks quite simple - the end of the pipe and the fitting are simultaneously heated with a soldering iron, then joined manually. Here lies the catch - at the slightest deviation from technological requirements the connection becomes unreliable.
Important point. Refinement or repair of an unsuccessful joint is impossible - the defective section is cut out, the connection is restored by using new fittings and extending the pipe (if necessary). Therefore, beginners should practice before serious soldering.
Controls and functional elements of the soldering heater How to properly solder pipes according to the instructions of polypropylene manufacturers:
- Use scissors to cut the pipeline to the desired size. If PPR is reinforced with aluminum, clean the end section with a shaver. The goal is to remove upper layer foil and adjust the outer diameter to the inner section of the shaped element.
- Set aside a distance of 14-22 mm from the end (see table below) and draw a mark on the surface indicating the immersion depth. If it is necessary to fix the position of the pipe relative to the fitting, mark the corresponding marks on both products.
- Turn on the soldering machine, set the temperature to +260 °C and wait until the heating indicators go out. Moisten a rag with white spirit and degrease the surfaces to be fused.
- At the same time, slide the pipe and fitting onto the mating nozzle profiles. Immerse the pipe end to the mark, not deeper. Maintain the required warm-up time, referring to the table.
- Also simultaneously pull the elements to be welded off the heater and quickly insert the end of the pipe inside the fitting (to the mark, not all the way!). The maximum time interval between removal from the device and docking is 3 seconds.
- Hold the joint with your hands for a few seconds (exactly indicated in the table). Evaluate the quality of the connection - the internal passage should not be blocked by the melt.
Note. Manufacturers of polypropylene categorically do not recommend rotating elements around their own axis during the process of attaching/removing/docking. The fitting and pipe are pulled off the soldering iron and connected only by straight movement.
As you can easily see from the table, the depth of immersion and the duration of exposure of parts on the apparatus depend on the diameter of the pipeline. If the specified time is exceeded, the polypropylene melt will close part of the flow area. If the joint is underheated, it will pass pressure tests, but after 1-2 years it will begin to leak.
Welding work is recommended to be carried out at an ambient temperature of at least +5 °C. If you have to cook polypropylene in the cold or in thirty-degree heat, the heating time should be adjusted by 50% in one direction or the other - the manufacturer’s recommendation. In practice, it is better to make several test joints and determine the exposure experimentally.
Assembling sections on the table
The highest quality pipe soldering occurs in convenient conditions when the welding machine is fixed on the table. Hence the conclusion: you need to divide the heating / water supply network into sections that can be made separately, and then connected to each other locally.
Try to do the maximum on the table welding work and form ready-made sections How to mark and weld sections of polypropylene pipes:
- Install plumbing and heating equipment - boiler, faucets, etc.
- Break the lines into separate sections so that the joints of the sections are in convenient places. Fasten to the walls along the intended routes pipe clamps– latches (otherwise known as clips).
- Calculate the lengths of straight pipes between each pair of fittings. 3 dimensions are taken into account: net length, immersion in the shaped element and the distance from the pipeline to the wall.
- Measure and cut straight pieces to size, put limiting and indicative marks.
- Degrease all ends and proceed to welding.
Examples of finished plumbing parts The greatest difficulty is caused by division into sections. Let's give an example: a two-pipe lower heating distribution is divided into long horizontal sections and radiator connections. The first are a pipe with a welded tee and coupling, the second are a figured element of several bends and pipes, ending with a threaded adapter for a faucet.
It is much easier to understand the technology of assembling sections by watching a video tutorial from an experienced craftsman:
We weld areas in inconvenient conditions
On-site installation begins with fixing the welded sections in clips installed along the route on the wall. The first section must be firmly secured so that the pipe does not slide inside the latches, or the other end must be rested against the wall. Then remove the soldering iron from the stand and weld the joint by weight.
Advice. It is better to carry out assembly work with an assistant; if necessary, he will hold one pipe or take the welding machine from you when both hands are needed for fast connection heated parts. If there is no one to help, you need to create a reliable support point in the first section so that the elements do not move in the clips.
Here, welding is carried out without any particular difficulties - the soldering iron tip is easily put on the pipes We will describe several techniques for welding polypropylene in hard to reach places:
- When the first section cannot be secured, ask an assistant to hold the pipe. After heating is complete, quickly hand him the soldering iron and connect the elements.
- If the “iron” heater rests against the wall, try releasing the ends of the pipes to be welded from the clamps.
- Option two: find a more convenient place for soldering, increase the length of the pipeline using a coupling and thus move the connection point.
- If the parts cannot be moved apart to the width of the heater, screw 2 identical sets of attachments to the iron and put both sections on one side of the mandrel, as shown in the photo.
- Experienced performers prepare a single joint in a deep niche where the apparatus will not fit in any position as follows: remove the heated nozzle from the mandrel with pliers and insert it between the parts to be joined.
Note. The latter method is considered quite risky - the removed nozzle cools down quickly, you need to be able to accurately determine the holding time. There is no room for error - when a joint leaks, you will have to redo part of the system and eliminate the consequences of flooding.
At the end assembly work do a pressure test - fill the pipeline network with water, pump up the maximum operating pressure and leave for 1 day. For details of installation and testing, see the second video tutorial:
PPR connection without welding
There are situations in life when the use of traditional soldering of polypropylene parts is excluded. For example, the joint is located in a hard-to-reach recess, or during installation the power suddenly turned off, and you only have to weld the last connection. There are 3 one-time methods:
- heating with a gas burner and subsequent docking;
- use of Gebo type compression coupling;
- planting elements on anaerobic glue.
Why are these options considered one-time use? Gluing and heating with a torch cannot provide the required reliability of the joint and are used only as a last resort on cold water supply lines. It is highly undesirable to connect heating and hot water pipes in this way. Gebo couplings are reliable, but too expensive.
The connection technology without a soldering iron is simple - the parts are degreased, gently heated with a burner flame, joined and fixed for 6-10 seconds. The technique is demonstrated in the video below.
Bonding is carried out according to the instructions on the packaging of the anaerobic sealant. The end of the pipe and the fitting socket should be cleaned, degreased and glue applied with a small brush. The elements are then fastened together using compression.
Conclusion
The method of soldering polypropylene pipes and fittings confirms the well-known rule: the cheaper the building material, the more labor needs to be spent on its use. It is much easier to install wiring made of metal-plastic, PVC and HDPE. Therefore, before final choice We recommend that you familiarize yourself with pipelines such as PPR and PEX (cross-linked polyethylene).
You can solder plastic pipes with your own hands, as this is more simple task compared to the technology of welding metal analogues. This joining method is used to work with polymer communications of different types. However, the techniques for soldering plastic pipes and reinforced analogues differ slightly. To avoid mistakes when welding communications, study the recommendations of specialists.
Soldering plastic pipes with your own hands.
Types of pipes connected by soldering
A soldering iron for working with polymer material is designed for joining water pipes, which differ in production technology and type of material:
- made of polypropylene - they tolerate high temperatures well, thanks to this property they can be used when installing a heating system;
- PVC: when exposed to strong heat, they partially lose their properties;
- plastic with reinforcement - due to the reinforcing layer, strength and resistance to heat increase, such communications are less susceptible to expansion upon contact with a heat source;
- heat-resistant polyethylene - tolerate long-term contact with coolant;
- polybutylene - superior in properties to analogues from other materials: they are durable, resistant to extreme temperatures, elastic, and can be used in pressure heating systems;
- sections of the copper pipeline are connected with a soldering iron or gas torch.
Necessary tools and materials for soldering
When you plan to repair or replace water supply networks, you will need a device for working with plastic.
Additionally, auxiliary tools are prepared:
- building level;
- pipe cutter or slicing scissors;
- a set of nozzles (included in the set of the welding machine for polymers);
- roulette;
- a shaver that allows you to remove the reinforcement of communications;
- chamfer;
- deburring tool;
- solder;
- flux.
Soldering iron for soldering plastic pipes.
Elements of the smallest diameter in everyday life are connected using the butt method much less often. Preference is given to fittings.
Solder for soldering
This consumables, used to connect copper sections of the pipeline. It is made in the form of wire, rods. Foil solder is also available. The materials of this group differ in composition. They can be produced on the basis of tin, zinc, lead, antimony, and silver. The quality of the seam joint depends on what metals are included in the composition. In addition, solder is divided into types based on exposure to high temperatures: low-melting, medium- and high-melting.
Fluxes and fittings
Fittings for plastic pipes for soldering.
Flux is necessary for welding metal parts. If you plan to use a machine for soldering plastic elements, this material is not used. Flux helps protect metal surfaces during the oxidation process. Another property of such materials is improved solder fluidity. Flux is available in different variants, differing in composition. Necessary materials for working with copper: zinc chloride, boric and hydrochloric acids.
Fittings are the connecting elements for pipelines: tees, couplings, crosses, etc. inner size must be equal to the outer diameter of the elements. This creates a reliable connection. However, if a PVC pipeline or other types of polymer structures are welded, then the seam connection using fittings in this case will be permanent.
Cutting scissors
The purpose of the tool is to make cuts on polymer products. If you use a pipe cutter, the edge of the communications will be more neat, and burrs will not appear. This makes further work easier.
Such a tool is presented different types, among which:
- auto;
- guillotine cutter;
- roller shears;
- pipe cutter with ratchet mechanism (suitable for working with communications up to 75 mm in diameter).
When you plan to weld plastic pipes with your own hands, you need to prepare the tool in advance, since polymer products cool quickly when heated. The main criteria for choosing a soldering iron for working with elastic communications:
- type of heating element: cylindrical, flat;
- the number of nozzles in the set, their outer diameter, which will allow you to work only with pipes of a given size;
- power – determines the heating capacity of the soldering iron; when doing the work yourself, a value of up to 1.2 kW is acceptable; when choosing a tool, the size of the connected communications is taken into account;
- the type of coating of the nozzles, it is important that the polymer material does not stick to them during soldering;
- type of temperature controller - affects the error in determining the temperature of the material.
The essence of the process and soldering methods
This technology is based on the principle of changing the structure of the material for joining individual sections of the pipeline. This ensures connection high degree strength.
Different ways to connect polymer pipes:
- electric welding installation technique – based on the use of special fittings equipped with conductive elements;
- soldering by heating parts: involves the need to change the temperature of the end sections and further compress them;
- cold welding of PVC pipes: chemicals are used that can change the structure of the plastic; after joining the pipeline sections, a permanent, strong seam is obtained, but in terms of reliability, such a connection is inferior to welding, and the elements of the system do not heat up.
Step-by-step instructions for soldering plastic pipes
During the installation of communications, it is important to avoid mistakes. If the installation technology is violated, the quality of the seam joint is significantly reduced, which leads to a reduction in the service life of the pipeline. The risk of leakage increases.
Security measures
Gloves must be used for work. Do not touch the heating element after turning on the device, as it tends to heat up to +300°C.
The room where welding work is performed must be ventilated. If there is a source of water nearby, it is important to protect workplace. Do not allow liquid to get on the soldering iron during the welding process.
It is necessary to make sure that the welding machine is in working condition - the integrity of the wire is not compromised.
Preparation of elements and parts
It is not recommended to connect raw communications. First, the material is cut in accordance with the design of the water supply system. Even if a pipe cutter is used, the burrs still need to be removed, since they are formed, although in smaller quantities. To make communications easier to connect to fittings, chamfers are made at the end sections (angle up to 45°). A special tool is used for this. Before starting welding work, the pipes are degreased.
Before soldering, the pipe is degreased.
Preparing the soldering iron
It is not difficult to operate the machine for welding polymer communications. It is installed on a stand and then connected to the network. At the same time, the required heating temperature is set (if there is such a function), which is implemented via a thermostat. After this, you just have to wait until the thermogulator warms up enough (use an electric thermometer). Duration of this period depends on the power of the unit and the heating rate. You often have to wait up to 30 minutes.
At what temperature should plastic pipes be soldered?
The temperature regime varies depending on the type of communications material. Most often, polypropylene pipes are used; the temperature for them is set at +260°C (upper limit). They work with polyethylene products under less aggressive conditions: temperature not higher than +220°C. In the absence of a thermostat, the main criterion is the heating time. The larger the diameter of the pipe, the longer it takes to warm up. The heating time varies from 6 to 20 seconds (for communications with a diameter of 20-63 mm).
Docking rules
The main requirement when installing polymer communications is compliance with the axis of the pipeline. They are flexible and become plastic when heated. This increases the risk incorrect installation pipes To avoid the formation of sagging inside the communications at the joint area, leave a gap of up to 3 mm between the edges.
Sequence of soldering plastic pipes.
Pipe connection
After waiting a sufficient amount of time, the pipe and fitting are removed from the nozzles. It is important to immediately connect them, installing them in the correct position relative to the axis of the pipeline. Complete hardening of the polymer material occurs in 2-3 minutes. However, closer to the end of this period of time, it is no longer possible to adjust the position of the pipe and fitting relative to each other. This will lead to the destruction of the formed molecular bonds. As a result, the quality of the connection will decrease.
Cleaning and cooling connections
Connecting the pipeline to the fitting.
After connecting to the fitting, the pipeline section is left in a stationary position. Wait until the temperature of the material decreases to +40°C (a change of 1-2°C is allowed). After this, it is necessary to partially remove the sagging. Under such conditions, the polymer material manages to gain strength, but still retains sufficient ductility. This makes it easy to remove beads without deforming the seam joint.
The pipeline section must not be subjected to artificial cooling. It should cool down outdoors. It is prohibited to use special means (blowing, low temperature sources or cold water) for this.
Checking the connection quality
The appearance of the pipe section is assessed. So, there should be no cracks in the seam. The material here should be uniform, without leaks, and the structure should not be porous. A connection without defects and with an influx of 2-4 mm is considered to be of high quality. If the pipe wall thickness is less than 10 mm, then leave a bead on the seam up to 2 mm high. When communications are welded bigger size, the overlap must be at least 4 mm.
Common mistakes
Inadmissible actions that can lead to a decrease in the quality of the seam joint:
- violation temperature regime when heating pipes: insufficient thermal effect or, conversely, overheating;
- complete removal of beads or cutting off excess material from the seam before it cools;
- applying excessive force when connecting pipes, which will lead to deterioration in the quality of the joint;
- if welding is carried out without preliminary treatment of communications, the seam will not last long, because dust and dirt remain on the pipes, which reduces the adhesion of materials.
If you do not have enough experience in performing welding work, you can study the recommendations of the masters.
Soldering in hard-to-reach places and corners
When work is carried out in areas where it is difficult to reach, it is permissible to heat the pipeline elements sequentially. First, you need to install a flange on the soldering iron nozzle, then a section of pipe. To prevent the first element from cooling down, it should be heated more strongly. To transition from difficult sections to the main pipeline line, angle fittings are used.
Connecting plastic pipes without soldering
If there is no welding machine, consider other methods:
- Cold soldering. In this case, it is assumed that a special adhesive composition must be applied to the inner walls of the pipe and the outer surface of the fitting. The material can be pre-treated with sandpaper, then the pipeline elements are degreased and connected.
- Application compression fitting: a connecting element is used, which is fixed with a nut.
Welding large diameter plastic pipes
If there is a need to install larger communications, use the butt connection method. In this case, fittings are not used. A minimum gap is left between the pipes; they are fixed with special equipment. After alignment is completed, proceed to soldering.
The ability to assemble pipelines yourself is a definite plus of polypropylene products. Using convenient and lightweight material, you can build a sewer system yourself, repair and modernize the water supply system.
The main thing is to understand the specifics of connecting prefabricated elements to each other. Agree, this is an important part of the work, responsible for the tightness of the highway and its trouble-free operation.
We offer you detailed information about how polypropylene pipes are soldered, what equipment is used in the work, and also list the most common mistakes made by novice welders.
The information we offer will help you build trouble-free communications. For clarity, the article is supplemented with graphic applications and a video guide.
The soldering process is carried out due to the pronounced thermoplastic properties of the material. Polypropylene softens when heated - it acquires a state similar to plasticine.
Image gallery
This is what a soldering iron (“iron”) for polypropylene pipes looks like. A simple electrical device, semi-automatic, thanks to which plastic soldering is done
The designs of soldering machines for butt welding are characterized by increased complexity. Typically, such equipment contains not only a heating element, but also a system for centering the parts being welded.
As a rule, direct welding equipment, like the technology itself, is rarely used in the domestic sphere. Priority of use is industry.
A more complex device, with the help of which precise alignment of the parts to be welded is carried out with the further process of heating and soldering. Used with direct welding technology
In addition to soldering irons, the master will also need:
- scissors - ;
- construction tape;
- bench square;
- shaver for pipes with reinforcement;
- marker or pencil;
- surface degreasing agent.
Since the work is performed on high-temperature equipment, you should definitely wear thick work gloves.
Polypropylene Welding Procedure
Important warning! Welding work polymer materials must be carried out in conditions of good ventilation of the room. When polymers are heated and melted, toxic substances are released, which in a certain concentration have a serious impact on human health.
The procedure for welding polypropylene is simple, but it requires precision and accuracy in work. You should also avoid common mistakes, such as insufficient or excessive heating
The first thing you need to do is prepare for work:
- Install blanks of the required diameter on the heater plateau.
- Set the regulator to 260ºС.
- Prepare the mating parts - mark, chamfer, degrease.
- Turn on the soldering station.
- Wait for the operating temperature to reach – the green indicator turns on.
Place the mating parts (pipe - coupling) on the soldering station blanks at the same time. In this case, the polypropylene pipe is inserted into inner area one blank, and the coupling (or socket of a shaped part) on the outer surface of another blank.
Typically, the ends of the pipe are inserted along the border of the previously marked line, and the coupling is pushed in until it stops. When curing polypropylene parts on heated blanks, you should remember an important nuance of the technology - the holding time.
Image gallery
Conclusions and useful video on the topic
There is always something to learn from professionals. You can see how to work with polypropylene in the following video:
Installing pipelines made of polymers by hot soldering is a convenient and popular technique. It is successfully used in the installation of communications, including at the household level.
People without extensive experience can use this welding method. The main thing is to correctly understand the technology and ensure its execution exactly. And technological equipment can be purchased or rented.
Do you have experience soldering polypropylene pipes? Please share information with our readers. You can leave comments and ask questions on the topic in the form below.
Any modern housing, be it a private mansion or city apartment, must be equipped with a variety of engineering communications. And if so, then either during the construction process, or during repairs or reconstruction, sooner or later the owners will have to face the problem of installing or replacing pipes and a heating system. Few people are now seduced by the labor-intensive and rather complex installation of steel VGP pipes. They are expensive in themselves, require considerable additional costs for transportation, and their processing and connection are associated with specific operations that not everyone can do - cutting, bending, electric or gas welding, thread cutting, etc. Plus, to the “packing” of everyone threaded connection A special approach is required to ensure that the connecting unit is of high quality and without leaks.
It’s good that modern technologies make it possible to avoid all this hassle by using polypropylene pipes. With the right choice of material and high-quality installation, plumbing and heating circuits are practically in no way inferior to steel ones, and in many respects they are far superior to them. In addition, the soldering of polypropylene pipes itself is not so complicated; instructions for its implementation will be discussed in this publication.
Not all polypropylene pipes are the same
Before starting to consider the installation instructions for polypropylene pipes, it makes sense to give at least a general idea about this material, in particular about its varieties and areas of application. Choosing pipes based on the principles of “which ones are cheaper” or “which ones were available” is completely unacceptable. The consequences for an unscrupulous home craftsman can be very sad - from deformation of the laid pipeline to its rupture or the appearance of leaks in connecting nodes.
There is no need to explain the difference in diameter - different systems and their different sections use their own dimensions, which are predetermined by hydraulic calculations. The range of diameters, from 16 to 110 mm, allows you to almost completely provide everything possible options. Moreover, practice shows that for a house or apartment, an assortment of up to 40 mm is usually sufficient, much less often – up to 50 ÷ 63 mm. Larger diameter pipes are, rather, main pipes, and they have specific features installation, but face it home handyman- it’s unlikely that you’ll have to.
The difference in color between some types of pipes may immediately be apparent. This is what you should pay least attention to - white, green, grayish and other walls - they don’t say anything. Apparently, this is simply a decision by manufacturers to somehow distinguish their products from the general background. By the way, for heating circuits White color will definitely be preferable, since the pipeline will unobtrusively fit into any interior without creating a disharmonious color “spot”.
But colored stripes, if they exist, already carry an informative load that is intuitively understandable to everyone. The blue stripe means the pipe is designed exclusively for cold water supply, the red stripe means it can withstand elevated temperatures. However, such color marking (which, by the way, very often does not exist at all) is only very approximate and does not fully reveal the operational capabilities of a particular pipe. It helps you simply not to make mistakes during the installation of the system. By the way, the longitudinal line is also good because it becomes a good guide when joining mating parts during soldering.
Much more information gives alphanumeric markings, which are usually printed on the outer wall. This is where it’s worth being more careful.
The international abbreviation for polypropylene is PPR. There are several types of material, and you can find the designations PPRC, PP-N, PP-B, PP-3 and others. But in order not to completely confuse the consumer, there is a clearer gradation of pipes - by type, depending on the permissible pressure of the pumped liquid and its temperature. There are four such types in total: PN-10, PN-16, PN-20, PN-25. In order not to talk at length about each of them, we can provide a plate that characterizes the operational capabilities and scope of application of the pipes.
polypropylene pipes
| Type of polypropylene pipes | Working pressure (nominal) | Pipe Applications | |
|---|---|---|---|
| MPa | technical atmospheres, bar | ||
| PN-10 | 1.0 | 10.2 | Cold water supply. As an exception - supply lines to the circuits of the water-heated floor, with a maximum operating coolant temperature of up to 45 °C. The material is the most affordable - due to its not particularly outstanding physical, technical and operational parameters. |
| PN-16 | 1.6 | 16.3 | The most popular option for autonomous cold and hot water supply systems, with an operating temperature of no more than 60˚C, a pressure of no higher than 1.6 MPa. |
| PN-20 | 2.0 | 20.4 | Cold and hot autonomous or central water supply. Can be used in autonomous systems heating, where there is guaranteed to be no water hammer. The coolant temperature should not exceed 80 ˚С. |
| PN-25 | 2.5 | 25.5 | Hot centralized water supply, heating systems with a coolant temperature of up to 90÷95˚С, including central ones. The most durable, but also the most expensive type of pipe. |
Of course, in order for a pipe to withstand elevated pressures and temperatures, it must have thicker walls. The value of the wall thickness and, accordingly, the nominal diameter of polypropylene pipes of various types is in the table below:
| Pipe outer diameter, mm | Type of polypropylene pipes | |||||||
|---|---|---|---|---|---|---|---|---|
| PN-10 | PN-16 | PN-20 | PN-25 | |||||
| Passage diameter, mm | Wall thickness, mm | Passage diameter, mm | Wall thickness, mm | Passage diameter, mm | Wall thickness, mm | Passage diameter, mm | Wall thickness, mm | |
| 16 | - | - | 11.6 | 2.2 | 10.6 | 2.7 | - | - |
| 20 | 16.2 | 1.9 | 14.4 | 2.8 | 13.2 | 3.4 | 13.2 | 3.4 |
| 25 | 20.5 | 2.3 | 18 | 3.5 | 16.6 | 4.2 | 16.6 | 4.2 |
| 32 | 26 | 3 | 23 | 4.4 | 21.2 | 5.4 | 21.2 | 3 |
| 40 | 32.6 | 3.7 | 28.8 | 5.5 | 26.6 | 6.7 | 26.6 | 3.7 |
| 50 | 40.8 | 4.6 | 36.2 | 6.9 | 33.2 | 8.4 | 33.2 | 4.6 |
| 63 | 51.4 | 5.8 | 45.6 | 8.4 | 42 | 10.5 | 42 | 5.8 |
| 75 | 61.2 | 6.9 | 54.2 | 10.3 | 50 | 12.5 | 50 | 6.9 |
| 90 | 73.6 | 8.2 | 65 | 12.3 | 60 | 15 | - | - |
| 110 | 90 | 10 | 79.6 | 15.1 | 73.2 | 18.4 | - | - |
With all the advantages of polypropylene, it also has a rather significant drawback - very significant linear expansion when heated. If for cold pipelines located inside a building this is not so significant, then for hot water supply pipes or heating circuits this feature can lead to sagging, sagging of long sections, deformation of complex junctions, and the occurrence of internal stresses in the body of the pipe, shortening its service life.
To minimize the effect of thermal expansion, pipe reinforcement is used. It can be aluminum or fiberglass.
The fiberglass reinforcing belt is always located approximately in the center of the pipe wall thickness, and does not in any way affect the soldering technology.
But with aluminum it’s a little more complicated. There are two types of such reinforcement. In one case, the foil layer is located in close proximity to the outer wall of the pipe (in the illustration - bottom left). Another option is that the reinforcing belt runs approximately in the center of the wall. For each type of such reinforcement, there are special technological installation nuances, which will be discussed below.
Both fiberglass and aluminum reinforcement significantly reduce the thermal linear expansion of polypropylene pipes. In addition, the aluminum layer performs another function: it becomes a barrier against oxygen diffusion - the penetration of oxygen molecules from the air through the walls of the pipe into the coolant.
The penetration of oxygen into the liquid coolant medium can cause a number of negative consequences, the main ones being increased gas formation and activation of corrosion processes, which is especially dangerous for metal parts of boiler equipment. The reinforcing layer can greatly reduce this effect, which is why such pipes are most often used specifically for heating circuits. In plumbing systems, it is quite possible to get by with fiberglass reinforcement, which does not have a significant effect on diffusion.
| Types of polypropylene pipes | Designation | Thermal expansion coefficient, m×10 ⁻⁴ /˚С | Oxygen diffusion indicators, mg/m²× 24 hours |
|---|---|---|---|
| Single layer pipes: | |||
| PPR | 1.8 | 900 | |
| Multilayer pipes: | |||
| Polypropylene, glass fiber reinforced. | PPR-GF-PPR | 0.35 | 900 |
| Polypropylene, reinforced with aluminum. | PPR-AL-PPR | 0.26 | 0 |
The illustration below shows an example of marking a polypropylene pipe:
1 – in the first place is usually the name of the manufacturer, the name of the pipe model or its article number.
2 – material of manufacture and structure of the pipe. In this case, it is single-layer polypropylene. Pipes with fiberglass reinforcement usually marked PPR-FG-PPR, with aluminum - PPR-AL-PPR.
Reinforced pipes with an outer polypropylene layer and an inner wall made of cross-linked polyethylene may be found. They will have a designation such as PPR-AL-PEX or PPR-AL-PERT. This does not affect the soldering technology, since the inner layer does not take part in it.
3 – standard pipe dimensional coefficient, equal to ratio outer diameter to wall thickness.
4 – nominal values of outer diameter and wall thickness.
5 – the type of pipe mentioned above according to the nominal operating pressure.
6 – list international standards, to which the product corresponds.
Pipes are usually sold in standard lengths of 4 or 2 meters. Most retail outlets practice selling with cuts in multiples of 1 meter.
Numerous components are available for sale for all pipes - threaded fittings for transition to another type of pipe, with external or internal threads or with an American union nut, couplings, tees, diameter transitions, bends at 90 and 45 degree angles, plugs, bypass loops , compensators and other necessary parts. In addition, it is possible to purchase taps, valves, manifolds, and “oblique” coarse water filters designed for direct soldering into polypropylene pipework.
In a word, such diversity allows you to choose the most convenient scheme for assembling a system of almost any degree of complexity. The cost of most of these parts is very low, which allows you to purchase them with a certain reserve, at least in order to conduct a small training session before starting practical installation - so to speak, “get your hands on it.”
Methods for connecting polypropylene pipes
Polypropylene is a thermoplastic polymer - when heated, its structure begins to soften, and when two fragments uniformly heated to a certain temperature are connected, mutual diffusion occurs, or rather, even polyfusion, that is, interpenetration of the material. When cooling, the properties of polypropylene do not change, and with a high-quality connection - ensuring optimal heating and the required degree of compression, after reverse polymerization there should be no boundary as such - a completely monolithic assembly is obtained.
It is on this property that the main technological methods connections of polypropylene pipes - this method is often called polyfusion welding.
Such welding (soldering) can be carried out using a socket or butt method.
- Sleeve welding is precisely the technology that is most often used when installing water pipes or heating circuits in a house or apartment. It is designed for small and medium diameter pipes, up to 63 mm.
Its meaning is that any connecting unit involves the use of two parts - the pipe itself and the coupling, the inner diameter of which is slightly smaller than the outer diameter of the pipe. That is, in a normal, “cold” form, the parts cannot be paired. The coupling can be not only, forgive the tautology, the coupling itself, but also installation area tee, elbow, tap, threaded fitting and other components.
The principle of such welding is shown in the diagrams below.
The pipe (item 1) and the coupling or any other connecting element (item 2) are simultaneously placed on the heating elements of the welding machine.
A pair of the required diameter is pre-installed coaxially on the working heater itself, consisting of a metal coupling (item 4), into which the pipe will be inserted, and a mandrel (item 5), onto which the necessary connecting element is placed.
During the heating period, a belt of molten polypropylene of approximately the same width and depth is formed along the outer surface of the pipe and the inner coupling (item 6). It is important to choose the right heating time so that the melting process does not penetrate the entire pipe wall.
Both parts are simultaneously removed from the heater and coaxially, with force, connected to each other. The melted plastic outer layer of polypropylene will allow the pipe to fit tightly into the coupling until it stops, the length of the heated section.
At this stage, the process of polyfusion, cooling and polymerization occurs. The result is a reliable connection, which, although shown in the diagram as a shaded area (item 7), in reality, if you look at the section, it is not visible at all - it is practically a monolithic wall.
- Butt welding is performed slightly differently.
One of the main differences is that the parts that are joined must be the same in inner and outer diameter.
The first step is to fine-tune the ends to ensure they fit perfectly together.
The pipes are pressed on both sides against a trimmer - a rotating disk (pos. 2) with precisely aligned knives (pos. 3)
The pipes are again pressed towards the center, and at the ends, over the entire wall thickness, areas of polypropylene melting are formed (item 5).
And, by analogy with the previous case, as the weld cools, it polymerizes, creating a reliable connection between the two pipes.
The principle seems simple, but this is only at first glance. With this welding technology, precise alignment of the mating parts is of decisive importance. In addition, during sleeve welding, the required degree of compression of the mating molten sections is ensured to a greater extent by the difference in the diameters of the parts. In this case, a significant external force is required, directed strictly along the axis of the connected pipes. All these conditions can only be met when using a special, rather complex machine-type apparatus.
There are many machines for butt welding, but almost all of them have a powerful frame with guides and clamps for clamping pipes of various diameters - to ensure joint alignment, a removable or folding end cap and heater, a mechanism for creating the required compression - manual, hydraulic, electric, etc. .P.
This technology is used, as a rule, only by professionals when laying main pipes, and the likelihood of encountering it at the household level is almost zero.
There is also a “cold” welding method - using glue based on a strong organic solvent. The point is that when treated with this composition, the surface layers of the polymer soften. The parts can be connected in the desired position at this time, and since solvents are usually highly volatile, they evaporate quickly. then the reverse polymerization process begins quite quickly.
This technology is more suitable for polyvinyl chloride (PVC) pipes that do not have proper thermoplasticity. In addition, this type of connection method has, perhaps, more disadvantages and limitations in use than advantages, so it is not in particular demand, especially since there is a simple and accessible technology for sleeve polyfusion welding.
What is required for installation work
So, in the future we will consider exclusively socket polyfusion welding (soldering). To cope with this task yourself, you need to prepare a number of tools and accessories.
- First of all, this is, of course, a machine for welding polypropylene pipes. Such a tool is not so expensive, and many zealous owners already have it in their home “arsenal”.
The welding machine must be supplied with coupling-mandrel kits of the required diameters. Most devices allow you to simultaneously place two, and sometimes three pairs of working nozzles on their heating element, which allows you to install a system that uses pipes of different diameters without interruptions for replacement.
If you don’t have your own device, and circumstances currently do not allow you to purchase one, then many stores practice short-term rental with a daily fee - you can take advantage of this opportunity.
If you decide to buy a machine for welding polypropylene pipes...
All welding machines are designed approximately the same and operate on a similar principle, but they also have certain differences in layout and functionality. Helpful information for those who have decided to make such a purchase, it is posted in an article on our portal, specifically dedicated.
In the text you may find the definition of a pipe soldering machine - but this is just a “play on words”. There is no difference between these concepts in this case.
- To cut the pipe, special scissors are required. Moreover, they must be sharpened, with a working ratchet mechanism that ensures a smooth cut. The blade should not be jagged or bent.
Of course, you can cut the pipe with a hacksaw, just a metal blade, or even a grinder, but this is absolutely not a professional approach, since the required accuracy and evenness of the cut cannot be achieved with such tools.
machine for welding polypropylene pipes
- It is necessary to prepare a marking tool - a tape measure, a ruler, a construction square, a marker or a pencil. To correctly place the pipes, you have to resort to a level.
- If you plan to solder polypropylene pipes with aluminum reinforcement, then additional tools are required.
- if the pipe has external reinforcement, then a shaver will be required to clean the aluminum layer at the weld penetration site.
- if the aluminum reinforced layer is located deep in the thickness of the wall, then the pipe still requires preliminary preparation, but in this case a trimmer is already used.
A trimmer is often similar in appearance to a shaver, but there is a difference between them - it lies in the arrangement of the knives. With a shaver, the cut goes tangentially parallel to the axis of the pipe, and with a trimmer, as even their names make clear, the knife processes the end and removes a small chamfer.
Read a useful article, and also familiarize yourself with the varieties and selection criteria on our portal.
We will dwell on this point in more detail when considering pipe soldering technology.
- Many people overlook this, but the welded sections of pipes and couplings must be cleaned of dirt, dust, moisture, and then degreased. This means you need to prepare a clean rag and an alcohol-containing solvent (for example, regular ethyl or isopropyl alcohol).
But use acetone-based solvents, esters, hydrocarbons - should not be used, since polypropylene is not resistant to them, and the walls may float
- It is also necessary to take care of protecting your hands. They will have to work in close proximity to the heating element of the device, and getting a serious burn is as easy as shelling pears.
Suede work gloves are best suited for this task - they practically do not restrict movement, will not begin to smolder from contact with a hot heater, and will reliably protect your hands.
And one more important warning. Most installation work can very often be carried out not locally, but, for example, on a workbench in a workshop - some devices even have special brackets with clamps for secure fixation on the table. This is convenient in the sense that the assembled unit is then quickly installed, for example, in cramped and uncomfortable conditions of a bathtub or toilet.
In any case, wherever soldering is carried out, it is necessary to provide highly effective ventilation. When polypropylene is heated, a gas with a pungent odor is released. The smell is not the worst thing - with prolonged inhalation, serious intoxication can occur. Believe me, I tested it on my own skin. The author of these lines spent a day with a temperature of 39° after seven hours of work in a fairly spacious combined bathroom, with a ventilation vent that seemed to work well. Don't repeat the mistakes!
How to solder polypropylene pipes
General technological methods for welding polypropylene pipes
- First of all, a novice master must have a clear idea of what he is going to mount. Must be prepared detailed diagram-drawing, with dimensions and specific details indicated - this same “document” will become the basis for the purchase required quantity pipes and components.
- If conditions permit, for example, there is no finishing in the room where the installation will be carried out, then it is best to transfer the diagram directly to the walls - it will be more clear, and you can measure the required lengths of pipes literally on the spot.
The key to success is to try to complete the maximum possible number of knots in a comfortable working position, on a workbench. Working with a soldering machine directly on site, and even alone, without an assistant, is an extremely difficult task, and it is very easy to make an error. It is clear that such operations cannot be completely avoided, but their number should be reduced to the possible minimum.
- The soldering machine is getting ready for use. Working pairs - couplings and mandrels of the required diameters for operation - are put on its heater and tightened with a screw. If you plan to work with one type of pipe, then there is no need to be clever - put on one pair, as close as possible to the end of the heater.
There are welding machines with a cylindrical heating element - it has a slightly different fastening of the working elements, like a clamp. But figuring this out is not difficult.
- It will be much more convenient to work if the device is rigidly fixed to the working surface of the workbench. It’s great if the design provides a clamp-type screw for fastening to the edge of the tabletop. But even with a conventional device, you can try to come up with some kind of fixation. For example, if the surface allows, the legs of the stand are screwed to the workbench with self-tapping screws.
Even with the stand fixed, the device can “wiggle” in it - there will definitely be some play. Here, too, you can provide your own fastening - drill a hole and screw in a self-tapping screw. When you need a soldering iron for remote work, removing this mount is a matter of a few seconds.
- The soldering iron is connected to the network. If it has temperature control, it is set to approximately 260 °C - this is the optimal temperature for working with polypropylene. You should not listen to anyone that for the 20th pipe you need 260 degrees, for the 25th - already 270, and so on - increasing. The temperature is the same, the heating time of the mating parts simply changes. In any case, those tables that the manufacturer provides in the product data sheet, and which will be posted below in this article, are designed for exactly this level of heating.
- Usually the soldering iron has a light indicator. A lit red light indicates that the heating element is working. Green – the device has reached operating mode.
However, many models have their own display features. Some devices even have a digital display with temperature indication. In any case, the device will “let you know” that it has warmed up to the required level.
- The mating parts are prepared for work - the required piece of pipe is cut off, the connecting element is selected according to the installation diagram.
- Not many people do this, and yet the technology requires mandatory cleaning of the connection area from possible dirt and dust, and degreasing. In addition, even the slightest drops of water or a wet surface are completely unacceptable - water vapor can enter the melt layer, create a porous structure there, and this connecting unit risks leaking sooner or later.
- The next step is to mark the connection. On the pipe it is necessary to measure from the end and mark the length of the penetration belt with a pencil (marker). It is up to this mark that the pipe will be inserted into the heating coupling, and then into the connecting piece. Each diameter has its own value - it will be indicated in the table below.
The second mark is applied if the relative position of the mating parts is important. For example, on one side of a pipe section a 90° bend has already been welded, and on the other side it is necessary to mount, say, a tee, but so that its central channel is located at an angle to the bend relative to the axis. To do this, first accurately determine the position of the parts, and then apply a mark across the border, along both sides.
There won’t be much time spent choosing the correct position during soldering, and such a “trick” will help accurately position the mating parts.
- The next step is directly soldering the connection. It, in turn, also includes several phases:
— From both sides, the pipe is simultaneously inserted into the soldering iron coupling, and the connecting element is put on the mandrel. The pipe must go up to the mark made, the connecting element - all the way.
— After the pipe and connecting element are inserted completely, the warm-up time begins. Each diameter has its own optimal period, which should be followed.
— Once the time has expired, both parts are removed from the heating elements. The master has literally a few seconds to give the parts the correct position and, of course, alignment, insert one into the other with force and bring it to the same mark. Light adjustments, without turning relative to the axis, are allowed only for one to two seconds.
— In this position, the parts must be held, without the slightest displacement, for the specified fixation period.
— After this, the assembled unit should not experience any load during the established period of cooling and polymerization of polypropylene. And only then can it be considered ready
Now - about the main parameters that must be adhered to during installation. For ease of perception, they are summarized in a table:
| The name of indicators | Pipe diameter, mm | ||||||
|---|---|---|---|---|---|---|---|
| 16 | 20 | 25 | 32 | 40 | 50 | 63 | |
| Length of the pipe section to be welded, mm | 13 | 14 | 16 | 18 | 20 | 23 | 26 |
| Heating time, seconds | 5 | 5 | 7 | 8 | 12 | 12 | 24 |
| Time for rearrangement and connection, seconds | 4 | 4 | 4 | 6 | 6 | 6 | 8 |
| Time to fix the connection, seconds | 6 | 6 | 10 | 10 | 20 | 20 | 30 |
| Time for cooling and polymerization of the unit, minutes | 2 | 2 | 2 | 4 | 4 | 4 | 6 |
| Notes: - If thin-walled PN10 type pipes are welded, the heating period of the pipe itself is halved, but the heating time of the connecting part remains the same as indicated in the table. - If work is carried out outdoors or in a cold room at a temperature below +5°C, then the warm-up period is increased by 50%. |
|||||||
There is no question of reducing the set warm-up time (except for the case mentioned in the note to the table) - a high-quality connection will not work, and the unit will definitely leak over time. But about some slight increase- the masters have no unity of views. The motivation here is that pipes from different manufacturers may differ slightly in material, that is, harder or, conversely, soft polypropylene is found. But the masters have accumulated experience and precise knowledge of the material used, but for a beginner, the recommended indicators should still be taken as a basis.
Good advice - when buying pipes and components - take a small supply of the cheapest connecting elements and conduct an experiment - training. You can prepare a few pieces of pipe and perform test soldering.
With high-quality soldering, a neat collar about 1 mm high is created inside the connecting node around the circumference, which will not interfere with the free passage of water. A neat bead will also be formed on the outside, which will not spoil the appearance of the connection.
pipe cutters
But overheating can already lead to a defective connection. When the parts are combined, molten polypropylene begins to be pressed inward, where a “skirt” is formed and hardens, largely covering the passage. The water pressure in such a water supply may be reduced, and in addition, such a defect often becomes a place for blockages to form over time.
Conducting such a practical lesson will help you accurately determine all soldering parameters and avoid mistakes.
Features of working with pipes with aluminum reinforcement
As mentioned above, there are two options here - the reinforcement layer is located near the surface of the pipe, or deep in the wall. Accordingly, the methods of preparing the pipe for welding also differ.
- It is clear that the layer of aluminum located near the surface simply will not allow for complete heating and connection of the assembly. In addition, such pipes always have a slightly higher diameter and simply will not fit into either the heating coupling or the connecting element. This means that it is necessary to peel off this layer to “pure” polypropylene.
For this, a special tool is used - a shaver. A piece of pipe is inserted into it and they begin to turn - the installed knives carefully cut off the top polymer coating and the aluminum underneath.
Processing is carried out until the pipe stops at the bottom of the tool - the dimensions of the shaver are such that it will cut the foil exactly in the strip that is required for the welded joint at a given diameter, that is, you don’t even have to carry out the appropriate markings.
When soldering, the entire cleaned area must be heated and then completely inserted into the connecting piece. Leaving even a thin strip of protected pipe outside is prohibited.
- If aluminum foil is hidden in the bottom of the material, then it would seem that it does not allow for high-quality soldering. But there is already another nuance here.
If the pipe is not protected at the end, then water passing under pressure will try to delaminate it and find a way out between the aluminum layer and the outer polypropylene sheath. Aluminum, in addition, can begin to corrode and lose its strength. The result of such delamination first becomes “blisters” on the pipe body, which then inevitably end in a major accident.
The solution is to create conditions such that during welding the end of the pipe and the aluminum layer are completely covered with molten polypropylene. And this can be achieved by processing with a special tool, which was mentioned above - a trimmer.
Outwardly, it may be similar to a shaver, but its knives are located differently - they precisely align the end, cut a chamfer and remove a thin, about 1.5 - 2 mm from the edge, strip of aluminum foil around the circumference. During heating and during the mating of parts, the created bead of molten polypropylene will completely cover the end of the pipe, and the assembly will receive the necessary reliability.
Pipes with fiberglass reinforcement do not have any installation features.
- The soldering process, as stated, is best carried out on a comfortable, spacious work site, assembling ready-made water supply (heating circuit) units as much as possible, and only then installing and connecting them in place.
Working “next to the wall” is always more complex, time-consuming and nerve-wracking, since you have to hold a fairly heavy apparatus with one hand, while simultaneously providing heating to both mating parts. Often without an assistant this welded joint almost impossible to accomplish. Therefore, it is worth reducing the number of such operations to a minimum.
But it is important to avoid mistakes. To connect the assembly, it is necessary to provide a certain degree of freedom to the mating parts - they need to be moved apart to install a welding machine between them (plus the heating pair also has a certain width), then carefully, without distortion, insert it into the mandrel and coupling, after warming up, ensure progressive removal and then connection. It is necessary to foresee this point in advance - whether the available play is enough to perform all these manipulations.
- It happens that inexperienced craftsmen, having not foreseen this nuance, are faced with the fact that there is only one weld left, and there is no way to complete it. What to do?
The solution may be to weld a dismountable connecting pair into the cut pipe - a threaded fitting and a coupling with an American union nut. The connection turns out to be reliable, and soldering such elements even in such difficult circumstances is no longer difficult.
- If at least some component during installation raises even the slightest doubt, without any regret it should be cut out and other parts welded. Believe me, it won’t take much time and won’t entail serious expenses. But if, over time, such a dubious area suddenly leaks, the consequences can be very sad.
- The next group of errors has already been mentioned above - a violation of pipe soldering technology. This may include insufficient or excessive heating. The force applied to the parts during connection should be moderate. Compressing too hard will cause an inner “skirt” to form. No less dangerous is the insufficient application of force - the pipe does not fully enter the socket of the connecting part, there remains a small area with an increased diameter and a thinned wall - a potential place for a breakthrough!
- Do not forget to clean the welded parts from dirt and grease. This may seem unimportant, but in practice there are quite a few cases where such neglect subsequently resulted in a weak connection and the formation of a leak.
- It is very dangerous to try to change the position of parts during the setting and cooling of the connection. This may not appear outwardly, but microcracks appear in the connecting seam, which subsequently lead to accidents. If you don’t like the connected node, throw it away and make a new one, but don’t try to change it!
- When stripping a reinforced pipe, not even a tiny fragment of foil should remain in the cleaned area - this can become a potential site for a future leak.
- One more recommendation. It is clear that the material must be of high quality - you should not chase cheapness, since you can lose a lot more, especially since even branded polypropylene pipes and components for them are not so expensive. But there are cases when, during the installation of high-quality pipes, carried out in strict compliance with the technology, the connecting nodes nevertheless began to fail over time. And the reason is simple - it was really used quality material, but from different manufacturers. Seemingly insignificant differences in chemical composition and the physical and technical characteristics of polypropylene gave such an unexpected result - full diffusion of melts was not achieved.
Therefore, one final piece of advice: use high-quality pipes from one manufacturer. It’s probably clear that all components should also be of the same brand.
At the end of the publication, there is an educational video about soldering polypropylene pipes:
Video: a master shares the secrets of high-quality soldering of polypropylene pipes
Polypropylene is a popular material that is widely used in many construction and installation areas. And the water supply was no exception. Polypropylene lines are characterized by corrosion resistance, long service life, good thermal conductivity and tightness. The last criterion depends entirely on how correctly the soldering of plastic pipes is carried out. And you heard right. Polypropylene, unlike polyvinyl chloride, is necessary and can simply be soldered into a single structure using a special welding machine for polymers.
On how to use an iron (as a soldering iron for plastic is called in craftsman circles) and how to properly solder a plumbing system, see our material below with detailed video instructions.
Important: before deciding to install a water supply system made of polypropylene pipes, you should know that this material is prone to stretching when exposed to high temperatures. That is, if you use polypropylene pipes for the hot water supply line, then such communication may simply sag over time. Therefore for hot water Only aluminum-reinforced polypropylene pipes should be used.
In order to, following the instructions, solder the entire water supply system with its long-term operation, it is advisable to understand what type of pipes the master is working with. After all, polypropylene is divided into four categories, each of which is intended for use in certain conditions. Failure to follow operating instructions will negate all the efforts of the technician, and the water supply will ultimately fail.
So, polypropylene pipes come in four types:
- Tubes marked PN 10. Thin-walled material of small diameter, intended for use at temperatures up to 45 degrees. Can be used in a cold water system or underfloor heating.
- Tubes marked PN 16. You should be extremely careful here. Polypropylene of this category can be used either in conditions high pressure in communication, but for cold water, or at low pressure in the hot water network.
- The PN 20 marking allows the use of plastic pipes for the construction of any pipeline operating at a temperature not exceeding +80 degrees.
- PN 25 tubes are those tubes reinforced with aluminum or fiberglass, suitable for installing a hot water supply system. Here the material can be used at temperatures up to 95 degrees Celsius.
In addition, it is worth understanding that all polypropylene pipes of any category can be sold different color. Color doesn't matter, other than black. This color of the pipes indicates that the PP tube is highly protected from UV radiation.
Important: all polypropylene pipes will be properly operated only if the operating pressure and temperature ranges in the network are observed. The higher the water temperature in the water supply, the lower the pressure should be, and vice versa.
Pipe soldering machine
Plastic pipes can only be soldered using special tool- soldering iron. The household unit is shaped like a kind of iron on a stand. Its heating base (mirror) is capable of warming up to temperatures above 260 degrees, which allows you to melt (solder) the polymer for a high-quality connection.
The heating base has places for attaching attachments. As a rule, in household appliance You can attach 2-3 attachments to the sole at the same time. Their diameter depends on the configuration that the purchased tool originally had. But most often these are nozzles with a diameter of 16-32 mm.
Important: you can only solder pipes with your own hands at home, the diameter of which does not exceed 63 mm. In this case, they are connected exclusively using couplings and fittings. Larger diameter pipes are soldered onto professional equipment and most often end-to-end.
You can solder plastic pipes with your own hands using either a sword-shaped apparatus or a cylindrical one. The quality of soldering will be unchanged and equally good if you follow the instructions.
Important: DIY work with a soldering iron should only be carried out in a room heated to above-zero temperatures. It is important to know that the cooler it is in the room, the longer the heating time for plastic and metal-plastic (in the case of a reinforced pipe) should be.
Preparatory stage
- First of all, you should prepare a pipe cutter, a marker and a tape measure. Using such tools, the tube will be marked and cut into individual elements.
- After all the metal-plastic and PVC parts of the future system have been cut, it is necessary to thoroughly clean with alcohol all places of intended connections, including couplings and fittings.
Important: aluminum-reinforced pipe is cut using a shaver. In this case, before soldering, you should first remove the top layer of polypropylene and aluminum. This will improve the quality of the connection. Fiberglass reinforced tubes are soldered in the same way as standard polypropylene.
For those who do not know how to properly solder plastic pipes (metal-plastic/PVC) at home with their own hands, you should adhere to the following recommendations when performing work:
- The soldering process begins no earlier than 5-10 minutes after turning on the soldering iron. It should warm up to the set temperature.
- Polypropylene pipes with a diameter of up to 40 mm can be successfully soldered using a sword-shaped apparatus. For larger diameter tubes it is better to use a more professional centering unit.
- After heating the polymer (PVC or metal-plastic), pieces will remain on the Teflon coating of the nozzles soft plastic. It is advisable to remove them immediately with a wooden spatula. It is impossible to clean off polymer residues on a cooled nozzle or using metal devices. There is a risk of damaging the Teflon coating and, as a result, damaging the part.
Important: timely cleaning of the nozzle from polymer residues allows you to obtain a guaranteed even and smooth connection.
Soldering process
So, solder polypropylene (PVC) elements of the water supply system with your own hands in several stages:
- A soldering iron is installed on the platform and securely fixed. The device is asked desired temperature. For polypropylene it is 260 degrees, for polyethylene - 220.
- Before turning on the soldering iron, attach nozzles of the required diameter to the platform.
- As soon as the device warms up, you can take a piece of tube and a fitting under it and put it on the nozzle. We maintain the parts in accordance with the diameter of the elements (see recommendations below).
- As soon as all parts of the pipeline are thoroughly heated, stand firmly and slowly join the parts until they fit tightly. Leave the communication section until it cools completely. All parts of the communication need to be soldered in this way.
Important: after the pipe is inserted into the fitting, it is prohibited to move it or rotate it in any way. The polymer (PVC) in the lumen of the pipe may shrink and the connection will depressurize.
After the pipes are soldered and cooled, you can blow water or air through them to check the tightness of the connection.
- For tubes with a cross-section of 16 mm - hold for 5 s;
- For tubes with a diameter of 20 mm - heating for 6 seconds;
- Pipes 25 mm - heat for 7 seconds;
- Elements 32 mm - solder 8 sec;
- Pipes with a diameter of 40 mm - heating for 12 seconds;
- Tubes diameter 50 mm - 24 sec;
- Pipe 63 mm - 40 sec.
Important advice: if the master is soldering polypropylene (PVC) pipes with his own hands for the first time, you can first practice on unnecessary pieces of polypropylene elements. In addition, if flaws were made in the connection during the soldering process, then you can simply cut off this section of the pipeline and solder a new one.
Advice: buying a soldering iron for a one-time DIY job is not financially feasible. In this case, it is better to rent a PVC pipe machine from a specialized hardware store.