The question often arises, what kind of material is polypropylene and how to solder polypropylene pipes. Today, to install plumbing, heating or sewerage systems, the popular method of soldering polypropylene pipes is used. This material is characterized by durability and high technical performance. Therefore, many are interested in how to properly solder polypropylene pipes to get an effective result. As with any installation, this process requires care and patience.
Soldering polypropylene pipes carried out using a soldering iron with special nozzles for heating pipes.
Technical characteristics of pipes
Before you start work, you should know what type of pipes are needed for a certain process, and how to properly perform it with a special tool for this. Their assembly is carried out using a soldering iron and fittings, which include couplings, angles, tees, etc.
This type of pipe is used when installing any type of pipeline. Moreover, they can be mounted in either open form, and closed, for example, when grooved in a wall. To solder them, connecting fittings are used, which provide a cast connection, and threaded ones, in which it is detachable.
Polypropylene pipes are divided into 4 types. The first PN10 includes pipes, operating pressure of which 1 MPa. They have thin walls and are used when installing heated floors and for supplying cold water up to +20 °C. PN16 grade material is used for conducting cold water, as well as for heating systems with low pressure. Pipes of the PN20 type are universal and have a working pressure of 2 MPa. They are installed when laying any water supply, both for cold and hot water. The last type PN25 includes pipes with an operating pressure of 2.5 MPa. This material is reinforced with aluminum foil and is intended for installation of any heating system, as well as for hot water supply.
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Rules for soldering polypropylene pipes
Required:
- soldering apparatus;
- special keys.
Polypropylene pipes are connected to each other using a soldering iron with special nozzles. These include a sleeve, designed to melt the surface from the outside, and a mandrel, necessary to melt the surface of the bell directly at the connecting part from the inside. These nozzles are coated with Teflon and have diameters ranging from 16 to 40 mm. After each welding, the non-stick material must be cleaned hot with a tarpaulin rag or wooden scrapers.
Before work, the welding machine is installed on a horizontal surface for stability so that it does not fall. And replaceable nozzles of the size required for the job are fixed onto it using keys designed for this purpose. Their location depends on convenience during the installation process.
So, for example, to install a pipeline branch located on the wall, they are placed closer to the end. When performing work in a vertical position and in inconvenient places, another person is needed for soldering. To obtain a better joining of polypropylene pipes, all elements of the future pipeline are assembled separately.
Polypropylene pipes should be soldered while observing the temperature conditions. The heating of the soldering iron directly depends on the temperature environment and lasts for 10-15 minutes. In hot weather, the welding time should be reduced, and in cold air, on the contrary, increased. If the temperature is below 0 °C, connecting polypropylene pipes and fittings using a soldering iron is prohibited. The soldering process of this material is ensured only at 260°C. You also need to choose the right time interval for soldering and cooling, which depends on the diameter of the pipes, i.e. the larger it is, the more time is spent.
The device's readiness for operation is indicated by an indicator. To obtain a strong and reliable seam, the soldering iron must be fully heated. Otherwise, the parts will not reach the temperature of viscous plasticity, so diffusion of the material will not occur. If the soldering iron is overheated, excessive adhesion of polypropylene may occur and, as a result, loss of shape stability. During the entire soldering process, the device must be turned on at all times.
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Required:
- polypropylene pipes;
- welding machine;
- plastic cutter;
- shaver;
- welded seat.
Soldering of polypropylene pipes can be done using a coupling, socket or butt method. With a coupling connection, two parts are fastened together using a special coupling, and for threaded joints, fittings with a socket are used. This type of soldering is used for polypropylene pipes with a diameter of less than 63 mm. Butt welding is carried out without additional details and is performed for pipes with a diameter over 63 mm. The socket method of soldering pipes with a small diameter is carried out either with a manual welding machine or with centering devices.
To perform socket soldering, first use scissors or a plastic cutter to cut the pipe to the required length at a right angle. If the product is reinforced, then the ends must be cleaned. To do this, the top two layers are removed with a shaver: polypropylene and aluminum. Stripping is performed to a depth along the tool stop, which determines the welding depth. Next, the surface of the parts is cleaned and degreased. After this you can start soldering. First you need to heat the soldering iron to the required temperature and after 5 minutes you can start the first welding.
Soldering of connections must be done quickly, otherwise deformation may occur.
When heating, a rotation angle not exceeding 100° is allowed. To avoid unnecessary movements during the welding process, you must first mark the corresponding landmarks on the pipes. Once soldering is completed, allow the time required for cooling, especially for thin-walled material. In this case, during the cooling process, under no circumstances should the elements be rotated or bent. If the fittings were connected incorrectly, the connecting fitting must be cut to correct the error. When welding elements such as angles, tees and ball valves, their location is taken into account, in which the handle must move freely to any position. At the end of the work, all welded elements are fixed together and are not subjected to any loads. Use a tool with clean attachments.
If there is a need to install an additional outlet on an existing pipeline, then welded saddles are used. In this case, the work will require a special apparatus with a drill and special welding tool attachments for them. First, a hole is drilled in the pipe wall at a temperature of 260°C. A heating fitting is inserted into it so that the tool completely reaches the pipe wall from the outside. After this, the seat fitting is installed in the heating sleeve, and the surface of the welded seat should be completely close to the arch of the tool. All elements should heat up within 30 seconds. Then you need to remove the welding device and quickly insert the fitting into the heated hole.
The welded seat is pressed tightly against the outer surface of the pipe and fixed in a stationary position for about 15 seconds. It takes 10 minutes for the connections to cool, and after that you can subject them to any load.
If you decide to install water pipes in your house or apartment yourself, you will have to learn how to solder polypropylene pipes.
But first, it’s worth understanding the difference between polypropylene pipes for cold and hot water. Let's not talk about cost (here the difference is not so significant), what is more important to us is the material from which they are made.
Kinds
So, cold water pipes are made only from polypropylene. But pipes for hot water supply and heating have an additional layer - foil. It serves as a kind of insulation and, at the same time, a frame that protects polypropylene from the harmful effects of high temperature. And, of course, pipes can be of different diameters.
Simple pipes
- carefully read the instructions for the soldering iron, paying special attention to the temperature-time tables;
- correctly measure and cut pipes.
Reinforced pipes
Typically, the reinforcing foil is located inside the thickness of the polypropylene from which the pipe is made, in this case the soldering process is identical to the soldering of conventional (non-reinforced) pipes. The situation is different with a polypropylene pipe having an outer reinforced layer.
Note! To solder a reinforced polypropylene pipe with a fitting, the foil will have to be removed.
To remove the foil, you need to use a special sharpening tool (shaver). After the foil has been removed from the section of the pipe that is heated by the soldering iron nozzle, you can proceed to normal soldering of polypropylene pipes with your own hands, but it is first recommended to remove a small chamfer from the outside and inside of the pipe.
If you are trying to solder polypropylene pipes with your own hands for the first time, you will most likely need an assistant to hold the soldering iron.
Note! If there is no need to solder pipes directly “on the wall,” it is better to choose a separate place for soldering (for example, a table), where you can do the work without bending or squatting.
Do not forget that the soldering iron gets very hot during operation and you only need to hold it by the handle.
Assembly
After the main elements of the pipe distribution have been soldered, they need to be assembled into one system and connected to the existing water supply outlets. To do this, you will have to solder polypropylene pipes with your own hands directly “on the wall”. Since heated polypropylene cools quite quickly, the soldering iron will have to be kept in a canopy and closer to the soldering site.
Video
This video shows in detail the process of soldering polypropylene pipes:
Photo
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 labor-intensive and fairly complex installation VGP steel pipes. They are expensive in themselves, require considerable additional costs for transportation, and their processing and connection are associated with specific operations that not everyone can do - cutting, bending, electric or gas welding, thread cutting, etc. Plus, a special approach is required to “packing” each threaded connection so that the connecting unit turns out to be of high quality, 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 you start considering the installation instructions for polypropylene pipes, it makes sense to give at least general concept 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 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 installation features, 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 is provided by 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, you can give 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 water-heated floor circuits, 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 nuances installation, 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, among which the main ones are increased gas formation and activation of corrosion processes, which is especially dangerous for metal parts 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 /˚СOxygen diffusion indicators,
mg/m²× 24 hoursSingle 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 inner layer does not take part in it.
3 – standard pipe dimensional coefficient, equal to the ratio of the outer diameter to the 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 of international standards to which the product complies.
Pipes are usually sold in standard lengths of 4 or 2 meters. Most retail outlets practice selling with cuts in multiples of 1 meter.
Numerous components are available for sale for all pipes - threaded fittings, for switching to another type of pipe, from external or internal thread or with an American union nut, couplings, tees, diameter transitions, floor bends at 90 and 45 degrees, plugs, bypass loops, compensators and others necessary details. 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 for joining polypropylene pipes are based - 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 - this is the pipe itself and the coupling, the internal diameter of which is slightly smaller than outside diameter pipes. That is, in a normal, “cold” form, the parts cannot be paired. A coupling can be not only, excuse the tautology, the coupling itself, but also the installation section of a tee, bend, 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 is pre-installed coaxially on the working heater itself required diameter, 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. In the end it turns out 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 under various diameters– to ensure the alignment of the connection, removable or tilting end trimmer and heater, a mechanism for creating the required compression – manual, hydraulic, electric, etc.
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 useful article, and also check out the varieties and selection criteria on our portal.
We will dwell on this point in more detail when considering 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, gas is released with pungent odor. 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. A detailed diagram-drawing must be prepared, 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 work surface 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, then it is set to approximately 260 °C - this is 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 in such a way that it center channel located at an angle to the outlet 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 time which should be followed.
- Once the time has expired, both parts are removed from 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 welded thin-walled pipes type PN10, then 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 regarding some slight increase, the masters do not have a unified view. 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 collar will also be formed on the outside, which will not spoil appearance connections.
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. It is often almost impossible to make such a welded joint without an assistant. 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
Soldering polypropylene pipes is remarkably simple to perform and forgives many mistakes without compromising the reliability of the pipeline. Our recommendations will help you do the work yourself.
In recent decades, metal-polymer pipes have become widespread for the manufacture of pipelines. They do not rust, do not become overgrown with internal deposits, have little resistance to fluid flow, and are easy to install.
Polypropylene pipes quickly gained popularity after their introduction. According to their characteristics, they are comparable to any other metal-polymer pipes, but have huge advantage: polypropylene fittings from any manufacturer are fully compatible with each other.
Which pipes to choose
An ordinary polypropylene pipe has a significant drawback that limits its scope of application: it greatly elongates when heated. To compensate for this thermal expansion, special compensators in the form of a loop are installed on the pipelines.
Reinforced polypropylene has a multilayer wall: the outer and inner layers are polypropylene, and between them is a layer of aluminum or fiberglass. For such products, the thermal elongation is approximately 10 times less. They can be walled into walls and therefore it is worth choosing them for plumbing, although they are more expensive.
The marking of polypropylene indicates maximum pressure COLD water for which they are designed. For household plumbing, you should buy materials designated PN20 and PN25, which means a pressure of 20 and 25 atmospheres, respectively. The diameter of the plastic pipeline is usually chosen to be 20 mm (outer diameter), which is equivalent to ½ inch steel pipe (inner diameter). Don’t be confused by the fact that the flow area of plastic pipes is sometimes chosen to be slightly smaller than that of steel pipelines: the exceptionally smooth inner surface offers almost no resistance to the flow of water and the performance of the pipe does not suffer.
Soldering tools
The main tool for soldering polypropylene pipes with your own hands – welding machine with nozzles of the required diameter. For a one-time job, you can buy the cheapest soldering iron. The price and design of the soldering iron determine only the ease of use, but not the quality of the connections obtained with its help.
You will definitely need a special cutter in the form of scissors, since there is a lot of cutting to be done.
Of course, you will need standard plumbing tools: adjustable and gas wrenches, flax, sealing paste. Polypropylene parts are connected to traditional steel parts using threaded combination couplings.
How to solder polypropylene
The principle of making welded polypropylene joints is simple: two parts are heated with a soldering iron until the material melts, then they are inserted into one another; After cooling, we obtain a solid monolithic part.
By combining pipe sections of different lengths and connecting elements With various configurations, you can assemble a pipeline of any complexity and branching.
Unacceptable mistakes when soldering pipes
The reliability of the resulting connection when soldering polypropylene pipes with your own hands depends on the temperature to which the parts are heated. The plastic must be softened so that the welded elements are connected with some effort and fit into each other to the required depth.
- If the parts are not heated enough, the plastic will begin to harden before you fully connect them. Such a connection may not leak immediately, but risks breaking before installation is completed.
- Overheated plastic is too soft and when connecting, the hot surfaces of the parts will not press against each other with sufficient force: “under-soldered” places will appear and almost certainly such a connection will immediately begin to leak. Another problem may arise. If you overheat the parts and then move them too hard, the molten mass of plastic will be squeezed into the pipe and completely block its lumen.
Sometimes there are recommendations to heat the elements to be welded for a few seconds. This is not always effective, since the heating time depends on many factors: the temperature of the soldering iron nozzle and the ambient temperature, the massiveness of the part and the diameter of the pipe, the refractoriness of a particular batch of polypropylene. If you don't have any welding experience, it's wise to take some time to practice.
There are several dozen places for soldering plastic pipes when installing a water supply system of medium complexity. And this is not surprising: each pipeline bend requires soldering twice, the branch consists of three welded joints.
And this is precisely where the main difficulty of the whole work lies. In most cases, welding has to be done “on site”. The configuration of the pipeline and the sequence of connecting its parts must be thought out taking into account the fact that the connections are made with a very bulky soldering iron, which is also heated to a temperature of 300 degrees.
Safety precautions
If you become familiar with the question of how to properly solder polypropylene pipes with your own hands, then you need to familiarize yourself with safety precautions, here are the basic rules:
- Use caution when handling a hot soldering iron to avoid burns.
- Hot polypropylene evaporates rapidly. It is necessary to provide sufficient ventilation to inhale as little of its vapors as possible.
- Remember about fire safety: Do not leave a working soldering iron unattended and always place it on a special stand.
- Fill the finished pipeline with water under pressure and check the connections for leaks.
Video
To clearly show how to properly solder polypropylene pipes, there is a video below to familiarize yourself with this process.
Surely it will not be a secret to you that modern high-quality repairs with the replacement of the heating system or plumbing it is not possible without the use of polypropylene, i.e. plastic products. This material quickly appeared on the market building materials, revolutionized the water supply system and firmly took a leading position. In this article we will talk about how to solder polypropylene pipes with your own hands and how to save on calling specialists. This is a kind of instruction for carrying out work.
Advantages of the material
In the life of a modern person, plastic is used in almost all spheres of his life. They have become simply indispensable components for repairs and construction of any scale: for heating, water supply, sewerage, etc. All because similar pipes for utility networkshave undeniable advantages over other materials:
- Do not corrode;
- They are highly resistant to chemicals;
- Excellent resistance to various types of microorganisms;
- They have low sound and thermal conductivity;
- Lightweight for easy transportation;
- Environmentally friendly;
- Not difficult installation;
- Can be laid in both open and hidden ways;
- Long service life - with proper operation up to 50 years of service.
Please pay attention! The optimal operating mode under which polypropylene pipes should be soldered by hand is: operating pressure up to 15 bar at a temperature of 0-10°C and up to 2 bar at a high temperature of up to 95°C.
It is thanks to its environmental properties that polypropylene is widely used in home water supply and heating. Wide choose fittings with various kinds of chrome or brass inserts makes it possible to use them with existing parts of engineering structures or plumbing items.
Necessary equipment
Let's look at how to solder polypropylene pipes with your own hands. For the installation of heating or water supply lines, products with an outer diameter of 16-63 mm are used. To connect them, socket or, as it is also called, sleeve welding is used. In order to solder you will need the following:
1. A soldering iron having a set of nozzles with different diameters. Well, how can you choose the appropriate soldering iron so that it is of high quality and allows for quick installation. The choice of tools is now really great, as are their price policy. A link to the selection rules will be after the article.
- The power of the tool plays a leading role. If you plan to use it at home to solder diameters 16-63 mm, then 1200 W will be enough for you. If you have to solder polypropylene pipes in hard-to-reach places and at a professional level, then you will need 1800 W or more. But let’s say right away that a novice installer will not necessarily need such professional devices at home.
- The included nozzles act as heating elements. They consist of a sleeve that melts outer part products and mandrel, which melts the inside of the socket of the connecting part. The nozzles must have a non-stick Teflon coating. Most often, a soldering iron kit comes with 6 nozzles of different diameters.
- The most convenient will be a soldering iron that allows you to install not one, but three nozzles. This design provides serious time savings, because you will spend much less of it in the process of replacing a nozzle of one size with another. After all, do not forget that to replace the nozzle you will need to cool it, replace it, and then warm it up again.
- A soldering iron that allows you to professionally solder products usually has electronic temperature control. It allows you to control heating with an accuracy of 1-5°C. Of course, you can do without this adjustment and simply buy a thermometer to measure the temperature of the working part.
Please pay attention! When you work, the soldering temperature of polypropylene pipes must be observed. It is important not to exceed the operating temperature of the nozzle of 260°C, at which polypropylene can be soldered. Already at 270°C, the plastic will lose its stability, will stick too much, and will not fit into the fitting. But if the working part is underheated, polypropylene will not reach the required viscosity and, as a result, the necessary diffusion of the material will not occur. The consequence will be an unreliable connection.
2. The next tool that you will need when you decide to figure out how to properly solder polypropylene pipes will be plastic scissors.
3. In addition, you will need a pencil, tape measure, tarpaulin rags, and, of course, polypropylene pipelines and the necessary fittings.
What types of fittings are there?
To understand what can be soldered and how to solder different sections, you need to understand what additional connecting elements there are.
- Solder couplings.
- Angles 45° and 90°. Used for both different and the same sizes.
- Tee or triple square.
- Crosses.
- Welded seat.
- Plugs.
- Soldering for polypropylene.
- Transition having outdoor type plastic thread DG.
- Combined couplings (with external, internal thread or union nuts).
- Combined tees (with external, internal threads or union nuts).
- Combined angles (with external, internal thread or union nuts).
- Combination angles for installation various types appliances (for example, mixer).
- Ball valves, straight or angled with American type.
- Walk-through water socket.
How to use a soldering iron
To understand how to solder polypropylene pipes, you need to understand the technology of the soldering iron. So, let's begin.
- The soldering iron must be placed on a flat surface. The nozzles are installed to the required diameter and tightened with special wrenches. A nozzle should be installed closer to the edge, which will be required in order to solder directly on the wall. It will be more convenient to assemble all separately located parts of the pipeline on a permanently located soldering iron, which you can do yourself. But you will need to assemble the parts into a chain on the wall with an assistant.
- Proper soldering should begin only after the tool has warmed up to operating temperature, approximately 10-15 minutes after it is turned on. Remember the nominal operating temperature in order to carry out soldering efficiently.
- The soldering iron must not be unplugged during the entire operation, i.e. while you solder everything.
- Two parts need to be heated at the same time.
- The plastic remaining on the nozzles must be removed with a tarpaulin rag after installing each fragment. It is not allowed to clean cooled attachments.
Soldering technology for polypropylene pipes
1. Using special scissors, cut the desired piece perpendicular to the axis.
2. Choose the right size fitting. Please note here that the unheated fitting must have an internal diameter that will be slightly smaller than the outer diameter of the pipeline.
3. Clean the end of the pipe and the socket of the fitting from dirt, degrease it with alcohol or soapy water and dry it.
4. Place the parts to be connected on the corresponding nozzle on the soldering iron. The product must be inserted to the full welding depth into the sleeve, and the fitting socket must be placed on the mandrel.
5. After placing the parts in the nozzles, it is necessary to maintain the heating time. Here you need to act in accordance with the data in the table below. Let us explain that the table indicates the time required to heat the parts. However, the data applies to an air temperature of 20°C. If you work at a lower temperature, then you need to heat the parts longer, and if at a higher temperature, then reduce it. The following table shows the soldering time for polypropylene pipes.
6. After heating, remove the parts from the soldering iron and connect them together. Here we draw attention to the fact that the connection must be made without rotation along its axis and to the entire depth of the fitting socket. The operation must be performed quickly while maintaining alignment.
7. If you did everything correctly, then after connecting, a continuous influx of plastic should appear along the edge of the socket. You can see an example below.
8. Next, allow time for the parts to cool. During this period, various types of deformations (bends or rotations along the axis) are unacceptable. Here we draw attention to the fact that if a connection has occurred and the alignment or angle of relative position is shifted, then the part must be cut out and reinstalled. You need to solder tees, angles and taps with special attention. For example, the faucet handle should move easily.
If you do not know how to properly solder polypropylene pipes, then it is advisable to perform test soldering. To check the quality of the soldering, you can cut the prototype along its axis. The result should be a monolithic structure.
Do not forget that the technology for soldering polypropylene pipes requires compliance with safety precautions, because... you will carry it out using high temperatures, power tools and plastic, which will emit harmful fumes when heated.
