Soldering technology for polypropylene pipes: preparation and process

Welding of polypropylene pipes is necessary when constructing heating or water supply systems in apartments and private houses. Correct joining of components helps to achieve strong fixation, tightness and safe use of the pipeline over a long period of time. At the same time, many novice craftsmen are interested in how to use a soldering iron for polypropylene pipes.

Soldering polypropylene products has certain features

Soldering technology

When heated, polypropylene becomes soft, resembling plasticine in consistency. Particles of liquid material mutually penetrate into the adjacent part. After cooling, it hardens and becomes resistant to tearing. The cooled seam is not inferior to the base material in technical parameters. To ensure a quality connection, it is recommended to meet the following conditions:

• polypropylene is heated with the device to a state of viscous fluidity, following the instructions in the instructions for the equipment;
• solder products from the same material, you should not connect polypropylene parts with different markings, the strength of the connection will be impaired;
• the ends and fittings are joined tightly, avoiding gaps and distortions; a tight fit is ensured by sanding the cut edge of the pipes with sandpaper;
• polypropylene hardens quickly, leveling is possible within a few seconds, after hardening it will be impossible to correct the defect.

Iron for welding pipes Source nehomesdeaf.org
Thanks to the thermoplastic characteristics of polypropylene, reliable joining of elements is ensured. A strong seam is obtained only if welding technology is followed and quality materials are selected. Let's look at how to solder polypropylene pipes below. On devices that support the installation of several nozzles, the sleeve can be installed in a convenient position. The location of the heating cartridge does not affect the quality of heating.

Which polypropylene products to choose

For low-pressure cold water supply networks, PN16 products are the most practical. They can easily withstand pressure up to 2 atmospheres at temperatures up to +40 degrees. This is quite enough to withstand the loads of a water supply system in a private home or a watering system in a greenhouse or garden.

Polypropylene pipes and fittings: types, markings, installation

Polypropylene products of the PN20 brand are more resistant to various influences, which are considered universal and can be used, among other things, for heating with a coolant temperature of up to 95 degrees.

But the most reliable pipes in any water supply system are PN25 pipes reinforced with aluminum or fiberglass.

Difficulty of welding

Test installation and connection of the first link of the system can be performed on a table or on the floor in a convenient place. Further welding on site is carried out under various technical conditions. Some areas of the system are difficult to access with an iron.

Before soldering pipes in hard-to-reach areas, it is recommended to choose a comfortable position. An inconvenient location causes delays in work and the appearance of various defects, for example:

• overheating of parts with melting of polypropylene and its spreading;
• the connection is deeper or smaller than required by the standard;
• installation with bending or rotating the element.

Installation of equipment on the platform Source static.onlinetrade.ru
When heating and connecting, synchronous actions should be observed: both parts are heated and removed from the nozzle at the same time. There is no delay before assembling heated parts. The pause occurs due to the need to place the device on the platform. Technical downtime directly depends on the experience of the technician and his speed of work. Errors in work lead to sagging, seam mixing, cracking and damage to the joint.

PPR pipe welding process

The key to success is to perform the maximum number of knots in one position on the workbench. It is better to carry out soldering work on PPR pipes with an assistant, because when installing it yourself, it is easy to make a mistake.

Preparing the soldering machine

Working pairs - mandrels and couplings - are put on the heater and tightened with special screws. Diameters are selected to suit working needs. If you intend to work with one type of pipe, then it is enough to put on one pair, located as close as possible to the end of the heater.

Important ! It is more convenient to work if the device is securely fixed on the working surface of the workbench. It’s good if the design includes a screw for fastening to the edge of the tabletop. If this is not possible, then you can screw the device to the surface with self-tapping screws. For such fixation there must be a special surface.

To work with polypropylene, you need to turn on the soldering iron temperature to 260 degrees. The temperature is the same for all pipes. Only the warm-up time changes.

Care must be taken to ensure that the operating temperature is reached. To do this, you need to view the display tools available on a specific device.

Important ! Before connecting and heating, be sure to clean the connection points from dust and dirt, and also degrease them.

Connection marking

The next step is to mark the connection. You need to measure the length of the weld belt and make a mark with a pencil or marker. This will be the place where the pipe will be inserted into the heating sleeve. Each diameter has its own indicator and must be followed. If necessary, an additional mark is applied if the relative position of the parts for mating matters.

Procedure for performing diffuse soldering

The ends are joined directly by socket soldering or using couplings. The coupling is a shaped part that is used as a connecting link. It is suitable for pipes with a diameter of up to 63 mm. Instead of a coupling, cuttings of pipes with a larger diameter than the section being welded are suitable. The section of pipe and coupling at the junction melts, providing reliable fastening.

Pipe cutting Source stroy-bloks.ru

A socket connection requires precise joining of pipe elements. The edges must be perfectly protected. Irregularities and burrs after trimming are not allowed. After the ends are melted by the apparatus, their diffuse connection occurs. If errors occur during trimming, a leak or rupture of the joint will form when water is supplied.

Alternative to welding

Sometimes it is impossible to carry out welding work in hard-to-reach places. An organic solvent can be used as an alternative to welding. It has pronounced softening properties. Moreover, the composition has high volatility.

Note! After lubricating the end of the pipe and the internal cavity of the coupling, it is possible to make the plastic softer for a short period of time. At this moment the connection is required.

Propylene pipes are very popular and are used for the construction of heating and water supply systems. To connect different elements you must use a soldering iron. To get a strong and reliable design, you must strictly follow the instructions for using this tool.

Preparation for welding

Before installing new pipes, it is recommended to draw a diagram of the pipeline on the wall. A simplified diagram represents lines drawn in accordance with the location of the future highway. Markings on the wall allow you to control the orientation of the pipeline.

In order not to adjust the pipes to size during soldering, you should measure the exact length of each pipe in advance. If the connection is made using couplings, allowance should be made for their installation. When installing end-to-end, deformation changes are taken into account. When melted, the pipe decreases by 1-2 mm.

Soldering iron attachments Source opttorg-volga.ru

For ease of welding pipes with a diameter of over 40 mm, an iron with centering is required. It can be used by craftsmen who know how to solder polypropylene. The tool comes with several different Teflon nozzles measuring 14-63 mm, which act as a heating element. There are nozzles in the form of a sleeve and a mandrel. The first type of heating element is designed to melt the outer part of the pipe, the second - from the inside.

Teflon nozzles must be clean. Do not leave particles of melted material on them. Immediately after soldering, the hot body is wiped with a coarse cloth that is resistant to high temperatures, for example, a tarpaulin. It is not recommended to clean cooled elements, otherwise the Teflon layer will be damaged, which will lead to the adhesion of molten polypropylene in the future.

Important points in assembling a piping system

Before starting welding work, it is necessary to carefully consider the entire structure and sequence of connections. It’s a good idea to prepare a sketch showing key elements, turns, tees, and expansion joints. Since the polyfusion joint is permanent, situations may arise when the manufacture of the next welding unit is impossible. This is a typical case for soldering polypropylene pipes in hard-to-reach places.

Consider temperature deformations

When installing polypropylene plumbing materials, one should take into account their special physical property - they stretch noticeably when heated. Of all types of pipes, in terms of the thermal expansion coefficient (0.15 mm/m*K), they are slightly inferior only to polyethylene. Therefore, soldering, in particular long straight lines or sections for termination, must be carried out taking into account compensation for their elongations.

When laying openly, U-shaped (1) or L-shaped (2) segments, manufactured on site or factory-made loop-shaped expansion joints for polypropylene pipes, are cut into the routes. It is also possible to compensate due to rotations in the system, and they must be able to move freely on supports

When embedding, the routes are laid in corrugations or canisters with a margin of diameter or in elastic sleeves with thick walls, such as Energoflex.

Temperature deformation in reinforced products is noticeably lower (about 3-5 times), which makes them more suitable for laying hot water supply and heating systems.

Important! The lack of temperature compensation leads to significant sinusoidal changes in pipeline geometry. The result can be torn fasteners when the installation is open, tiles or plaster torn from the wall when installed hidden.

Follow the rules for fastening the engineering structure

Reliable fixation for communications made of polymers is even more important than for their steel counterparts. The installation pitch and type of supports depend on the diameter of the polypropylene pipes, as well as on the temperature of the liquid transported through them. Violation of fastening rules can lead to sagging of pipelines, especially hot ones, their “bouncing” and knocking under the influence of pressure pulsation.

Table 2. Recommended support spacing for typical horizontal residential hot water and hot water supply lines, mm.

Water risers with a diameter of up to 32 mm can be secured less frequently. The distance between the fixing clamps is taken to be no more than 1000 mm. If the diameter of the risers is larger, then a step of up to 1500 mm is allowed.

When installing fasteners, it is necessary to ensure that they do not interfere with linear deformations of the polymer material. It is preferable to install sliding supports. Along the line of rigid fastenings, it is planned to install expansion joints on polypropylene pipes.

You should be aware that shut-off and control valves in systems with a nominal diameter of 40 mm must be firmly fixed. With smaller diameters, fastenings are also desirable to prevent the transfer of loads from the use of plumbing fixtures to the pipes.

Equipment preparation

Not all models include a stand. The soldering iron is installed on a level surface in an easily accessible place so that it does not tip over due to carelessness. Nozzles of the required diameter are placed nearby. Some types of irons allow you to simultaneously use replaceable components of different diameters.

Iron components Source teplo-online.com

See also: Catalog of companies that specialize in water supply and sewerage.

The heating element is heated evenly along its entire length to a predetermined temperature. The degree of heating is pre-set on the panel. For polypropylene, the soldering temperature of polypropylene pipes on the scale is set at 260⁰. Warming up the device lasts 10-15 minutes. A cold room takes longer to warm up than a heated room. At temperatures below 0⁰, welding is prohibited.

Common questions and answers about soldering polypropylene

Is it possible to solder pipes from one manufacturer and fittings from another?

Of course it is possible, but I would like to warn you that both couplings and pipes should be used of proper quality. You should not use parts from unnamed manufacturers. In unprofessional stores they often sell pipes from different companies, but the fittings are the same, from an unnamed manufacturer. I don't recommend using this combination. In general, nothing prevents you from soldering pipes and fittings from different manufacturers, with or without different reinforcement on different sides of the coupling.

Polypropylene sticks to the nozzles - what to do?

The first step is to check the actual temperature on the soldering iron - it is quite possible that it does not correspond to the temperature on the thermostat. Most often, melted plastic will begin to stick to scratched attachments, so they should not be cleaned with metal objects. The nozzle can be cleaned with thick paper or cardboard, but this usually does not have a long-lasting effect. If the nozzle begins to become actively dirty, then the most reasonable solution would be to purchase a new one.

However, you can temporarily get out of the situation if the nozzle is too “sticky”. To avoid damaging the weld and to keep the nozzle as clean as possible, you need to twist them a little when removing the pipe and fitting from the nozzle.

Is it possible to bend polypropylene pipes?

They cannot be bent, either during installation or after. If there is a need to bend the pipe during installation, then you should use contours or combinations of corners. To be fair, it is worth noting that the weak point of the bending pipeline is the junction of the pipe and the fitting. This mating point breaks off at some breaking force. To make sure of this, just solder a test structure from a corner and two 50 cm pipe sections, and try to break this “poker” with your hands.

Sometimes there is a need to solder a node with a non-standard angle. Let me remind you that PP corners come in only two types: 90 and 45 degrees, at least I haven’t come across any others. What to do if you need to turn the pipe to a different degree? There are two methods known to me:

Using two 45° corners, you can make any angle by changing the angle of rotation of the corners relative to each other. The disadvantage of this method is that due to the non-standard rotation, the connection will not be in the same plane.

The second way is to disrupt the alignment of the pipe and fitting at several connections. Do not forget that the straightness at the junction of the pipe and fitting should not deviate by more than 5°.

How to solder polypropylene pipes if there is no free movement?

There are various options, depending on the specific situation. This includes the use of 2 soldering irons, the use of detachable connections, and so on. However, if the installation is not carried out on the “front” section of the pipeline, then the simplest solution would be to make a bypass. In the simplest implementation, you can get by with 2 extra 90 degree angles. The whole point is that if we cannot move the pipes horizontally by soldering 2 corners, we can weld them together vertically or in another plane.

How to solder pipes if the faucet does not hold it?

It is strictly forbidden to weld if there is water in the area to be soldered. If for some reason it is not possible to completely shut off the water, you need to stop it while welding. On the Internet they advise plugging the pipe with bread crumbs, but the problem is that the crumb is immediately squeezed out by the newly created pressure in the pipe. Therefore, the method will only work when it is possible to open the area up to the soldering point for air to escape. And when the pipes are soldered, the crumb easily pops out when pressure is applied.

Advice: if during welding you could hear the hissing of water on the nozzle, it is better to cut out the assembly and redo it! It’s better to spend extra time during installation than to fix and eliminate leaks in the future, with a bunch of problems that pop up!

In this photo you can see that the plug on the filter is unscrewed and excess water flows down the cloth from there. And in the place of soldering the bread crumb is plugged. Thanks to the open filter, we had a little over a minute to do the soldering before the water squeezed out the crumb.

Actually, this is where I propose to end the presentation of information. Over time, I plan to expand the list of common questions about soldering polypropylene pipes.

Preparing pipes for welding

The edge of the pipe is cut with special scissors at a right angle. The cut area is sanded and degreased with ethyl alcohol or soap solution. The surface is thoroughly dried. Products marked PN 10-20 are welded immediately, and those with PN 25 are additionally cleaned with a shaver, removing part of the polypropylene and aluminum to the soldering depth. They are oriented according to the size of the nozzle up to the limiter.

Important! For degreasing, it is prohibited to use any solvents, gasoline, vodka, or acetone. Aggressive liquids corrode the surface of polypropylene.

When using a socket connection, it is important to adhere to the stripping depth and chamfer width. The degree of stripping must match the depth of installation of the elements.

Table for stripping pipes of different diameters

The pipes are different

Before starting to describe the installation instructions, it is necessary to define the materials, types and scope of application. Selecting pipes based on price or availability in a hardware store is unacceptable. The wrong choice can lead to difficulties after installation. These may include leaks, cracks and deformation. This leads to the need to redo the system and incur additional costs.

Hydraulic calculations determine the dimensional grid for pipes. Communications differ from each other and require different pipe diameters. The range of diameters ranges from 16 to 110 mm to cover almost all installation options and needs. Practice shows that the needs of an apartment are met by pipes with a diameter of up to 50 mm; exceptions are rare. Larger diameter main pipes. They require a special approach to installation and are rarely found in the work of a home craftsman.

Polypropylene pipes differ in color schemes. The shades and varieties of pipe colors are in no way related to performance characteristics and do not affect anything. They should not be taken into account. This is a standard solution for manufacturers, helping them make their products more catchy and bright against the general background. The only way to choose a pipe with a specific color and purpose is to purchase a white heating product. The color makes it possible to fit into any interior.

If there are colored stripes on the pipe, then they will carry an information load that is understandable to everyone. The blue stripe indicates the use of the product for cold water supply needs. The red stripe indicates the design to withstand high temperatures during operation. The color markings are approximate and carry minimal information load. Certain types of products are not burdened with even such markings. The line on the pipes helps determine the load, properties and becomes a guide when joining at seams. The line is a convenient guide during installation.

Alphanumeric markings carry the bulk of the information. You need to look for it on the outer wall of the product. Here it is worth showing special care and delving into what the manufacturer has written.

The polypropylene pipe has the designation PPR, accepted as the international marking of polypropylene. The designations PPRC, PP-B, PP-N, PP-3 and others are found when indicating the type of material. For the convenience of the user, a different marking system is provided, taking into account the type, pressure of the liquid, and pumped temperatures. In practice, four types of pipes are used: PN-10, PN-25, PN-16 and PN-20. The performance properties of the pipe and the maximum temperature of use depend on the number. PN-25 is used for heating needs and can withstand temperatures of 95 degrees.

Performance properties are directly dependent on the thickness of the pipe walls. Thick walls can withstand high temperatures and high pressure.

Polypropylene, despite its advantages, has a significant drawback - when overheated, significant linear expansion is observed. Cold water pipes located inside the building do not feel the negative influence of the expansion factor. Hot water supply pipes can feel the problem more significantly, experience deformation, the appearance of stress inside the structure, and sagging in long sections.

Reinforcement of polypropylene pipes is used to reduce the effect of thermal expansion. Reinforced with fiberglass and aluminum. The fiberglass reinforcement belt is located in the center of the pipe wall thickness and does not affect soldering.

Aluminum reinforcement is divided into two types. In the first case, the foil layer is located next to the outer wall of the product. An alternative option involves passing a layer of aluminum through the center. Both types differ in installation and design features.

Both reinforcement options make it possible to achieve a significant reduction in the level of expansion of pipes when heated. The layer of reinforcing material becomes a barrier against diffusion (oxygen penetration through the surface of the pipe inside it).

The penetration of oxygen molecules and their entry into the water inside the pipe causes a number of negative consequences: a significant increase in gas formation, the occurrence of corrosion processes, which is very dangerous for boiler equipment. A reliable reinforcing layer significantly reduces the negative impact on pipes and communications in general. Reinforced pipes are widely used in heating systems. Pipes for water supply are chosen with standard fiberglass reinforcement, which does not have a significant effect or influence on diffusion.

Pipes are sold in standard size sections of 2 m and 4 m. Retail outlets cut pipes in multiples of 1 meter. Special components are added to the pipes: threaded fittings for switching to another type of pipe, plugs, couplings, compensators, bypass loops, etc.

A variety of structural elements and consumables allows you to select options for assembling a system of any level of complexity. Consumables and parts are inexpensive, which allows you to purchase with the necessary reserves for installation and use.

Warming up polypropylene

Installation of polypropylene pipes includes two stages: heating of the joining areas and connection. The part is put on a nozzle of the appropriate diameter. The pipe is installed in the sleeve up to the limiter for the entire stripped length, and the fitting element is placed on the mandrel until it stops. It is necessary to control the heating depth; the pipe must be located in the sleeve without distortion until it stops at the limiter. Maintain the necessary time to warm up. The holding time and soldering temperature of polypropylene pipes depend on the product parameters; the table displays all the important welding parameters at a room temperature of +20⁰.

The heating time must not be exceeded, otherwise the surface will be deformed, which will lead to distortion of the geometry and the inability to join the parts without gaps. When joining molten sections inside the pipeline, polypropylene swelling appears, which hardens into large ridges. Protruding material reduces the passability of the highway.

Table of welding delay values ​​Source montagtrub.ru

Important! Temperature measurements on the iron mirror are carried out with a thermal probe.

Welding plastic pipes is impossible without a technical pause of a few seconds after heating, which is necessary to remove parts from the heating element. In a cold room, during this period the heated areas have time to cool down, which deteriorates the quality of the joining. To ensure a strong seam, it is recommended to increase the heating time by a few seconds so that the material melts more strongly. The optimal additional time is calculated by selection, taking into account :

• ambient temperature;
• nominal pipeline cross-section;
• holding time for warming up.

The temperature is set within 255-265⁰. If it exceeds 270⁰, the seam will turn out thin and unable to hold the water pressure. This occurs due to the rapid heating of the outer layer until it melts. At the same time, the material does not have time to warm up deeply, so diffuse penetration of polypropylene into adjacent areas of the parts does not occur.

Stages of pipeline welding Source svarkaspec.ru

Types of connection of polypropylene pipes

Many people are interested in how to properly use a soldering iron for plastic pipes. First you need to select the type of welding.

Socket welding

The method is simple. In this case, to fix pipes of the same diameter, a special element is used - a coupling. It has a slightly smaller diameter. During welding, the outer part of the pipe and the inner surface of the coupling heats up and melts.

A popular type of soldering is the coupling method.

Butt welding

This method is used in production conditions. In this case, the sides need to be melted and joined end-to-end. To get a good result, perfect alignment is required.

Note! The resulting connection is not very strong. Therefore, this welding method is not very common among craftsmen.

Cold welding

This method involves the use of glue. In this case, a special composition with a strong solvent is applied to the pipe. It helps soften the polypropylene, which allows the elements to be inserted into each other. In this case, the connection is not very strong. In addition, the glue takes a long time to dry.

Soldering Features

Welding of polypropylene pipes is carried out with quick movements by applying heated sections to each other so that the pipe section enters the fitting cup to the required depth. It is necessary to monitor the edge ratio to avoid distortion at the seam. Cleaning and length adjustment must be performed before welding, otherwise the system will depressurize due to static stress.

To prevent the seam from cooling down during a technical pause, the equipment is positioned so that the distance from the installation site to the installation of the device is minimal. This nuance should be provided for in advance. Time spent moving equipment and components results in heat loss. The seam is weak due to partial diffusion between the layers of polypropylene.

Welding technology for polypropylene pipes Source provodoprovod.ru

It takes 2-4 seconds to adjust the position. During this period, the elements cannot be rotated, bent or disconnected. If the seam fails, the area is cut off and the procedure is repeated. It should be remembered that such mistakes lead to a decrease in the length of the pipe and waste of material. If you have no experience or knowledge of the theory of how to properly solder polypropylene pipes, it is better to entrust welding to a professional.

Expert advice

To ensure maximum reliability of pipeline connections, experts advise adhering to the following requirements:

• it is correct to start welding work 10 minutes from the moment the soldering iron warms up;
• perform welding or soldering operations only at above-zero ambient temperatures;
• sections of pipes connected by welding must be allowed to cool, preventing them from moving relative to each other or twisting;
• For wall thicknesses greater than 6 mm, butt welding of products is performed using a double seam. With a smaller wall thickness, the joint can be sealed with one seam;
• all structural elements fixed by soldering must be from the same manufacturer, since they may differ in the composition of the ingredients in the raw materials, which will negatively affect the quality of the weld.

Sources

• https://VashPlastik.ru/kak-pajat-plastikovye-truby/
• https://dom-i-remont.info/posts/santehnika/payka-polipropilenovyih-trub-svoimi-rukami-pravila-sovetyi-oshibki/
• https://otivent.com/pajka-polipropilenovyh-trub
• https://ProUteplenie.com/otoplenie/payka-polipropilenovyh-trub-svoimi-rukami-polnaya-instruktsiya
• https://eurosantehnik.ru/pajka-polipropilenovyx-trub.html
• https://vse-otoplenie.ru/pajka-polipropilenovoj-truby-instrukcia-polzovania-utugom-tehnologiceskaa-tablica-sekrety-raboty
• https://iseptick.ru/truby-i-fitingi/polipropilenovye-truby/kak-payat-polipropilenovye-truby.html
• https://trubametr.ru/material/pp/kak-payt
• https://vseotrube.ru/montazh-i-remont/kak-payat-plastikovye-truby

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Cooling and leak testing

The seam cannot be cooled forcibly. Due to temperature changes, cracking and deformation in the melting zone is possible. The pipeline must be given time to cool naturally. You can control the temperature by touch. The cooled area is first checked for leaks by blowing. At the end of soldering, water is passed through the pipeline, gradually increasing the pressure, and the seams are inspected for leaks and permeability.

Pipeline installation Source https://i.ytimg.com/vi/qTaP9btjoP4/maxresdefault.jpg

Errors during soldering

Most often, errors occur among craftsmen who do not have practical experience in soldering, even when they know how to weld polypropylene pipes. Many people neglect the step of measuring the length of pipes, performing installation by eye with trimming after the fact, or they measure without taking into account tolerances. If the length of the pipe is incorrectly calculated, it is very difficult to install the iron for joining the elements.

Many craftsmen try to bend the pipe in place to increase the distance between the parts. This leads to an increase in static voltage in the network links and a decrease in tightness. Such errors worsen the appearance of the highway. Attention is paid to the aesthetics of the system when laying communications externally.

Sequential heating is a mistake that leads to rapid cooling of the joined areas and the impossibility of connection. While the second element is heating up, the first has time to cool down. Partial diffusion leads to rupture of the connection when pressure increases and water hammer. This is a gross violation of technology. It is absolutely impossible to operate such a highway.

Warming up parts Source https://www.malolikto.ru/wp-content/uploads/2016/12/maxresdefault-4.jpg

Kinds

Metal-plastic Polyethylene

Such communications are divided into subtypes:

1. Polyethylene - used for laying wiring inside buildings and external routes. They can be used on high-pressure pipe connections and at low ambient temperatures.
2. PVC is used to reduce the cost of repairs.
3. Metal-plastic ones are the most practical products, with a useful life of more than 50 years. Ideal option for replacing hot water supply.

The widespread use of this material is due to a number of reasons. Positive properties of such structures, in contrast to metal ones:

1. Long service life.
2. Low corrosivity.
3. Easy to install.
4. Does not require special skills.
5. Environmentally friendly material.
6. Economical and easy to use.
7. Lightweight and easy to transport.
8. Resistant to the harmful effects of microorganisms.

How to reduce the likelihood of marriage?

It is recommended that two people work together to solder elements in difficult-to-access conditions. The second specialist helps remove the second element from the nozzle and puts the soldering iron on the platform. The first master carefully joins the parts with both hands with a minimum pause. Sometimes assistance from a third party is required. His services are used when a pipe needs to be fixed in a wall in an adjacent room. Attempts to perform all operations independently in difficult areas always lead to defects and the need to perform welding again.

Planting depth marking Source files.builderclub.com

During soldering, precise movements must be observed. The correct inclination of the fitting element relative to the second part, its axial angle of rotation on the pipe, and the depth of entry into the fitting cup must be maintained. To control the depth of entry and the angle of rotation of the fitting, marks are made on the surface of both parts. In order not to measure the allowance each time on sections of the same cross-section, use a template.

The iron does not need to be turned off during the entire welding period. The technician will lose time warming up the equipment. The soldering iron is ready for use after the heating indicator goes out. A lit indicator shows that the mirror is heated to the desired temperature. If you start welding during this period, the pipe will not warm up properly. In order to comply with the technological process and holding time, it is recommended to check the parameters according to the table, which is recommended to be kept at hand.

If combined pipes are purchased, they are connected only after mandatory stripping. The chamfering depth should be 2 mm greater than the depth of the sleeve into which the element is inserted. Reinforcement reduces deformation expansion by 10 times. On products with external reinforcement, before soldering, a part of the surface is removed with a shaver to the required depth for joining. Pipes with internal reinforcement do not require stripping. Their installation is faster.

Nuances of work: how to solder plastic pipes without problems

The above instructions describe the general provisions for welding polypropylene pipes. But there are interesting points that can confuse an inexperienced master.

We work on the workbench and locally

Not all components of the future pipeline can be soldered comfortably on a prepared workbench. Of course, maximum work should be carried out there, and the point is not at all in the personal comfort of the master - this way there is less risk of incorrect connection of elements. But sometimes it is necessary to solder parts “in place”, so it is better to mark out the diagram of future communications on the wall, floor or ceiling in advance, and secure the clips that will hold the pipes in the desired position.

We fasten the welding machine

When inserting and removing heated elements, a tabletop “iron” that is not secured in any way will jerk in different directions. This leads to both problems with extracting fragments and burns (when trying to hold the falling apparatus), and its breakdown.

Therefore, it is better to fix the soldering iron on a workbench or desktop in any available way - using a “native” clamp or a clamp added to the design, self-tapping screws, and so on.

Cleaning is required!

One of the striking examples is the joining of products reinforced with aluminum not on the outside, but in the middle of the wall.

To properly solder such polypropylene pipes, it is necessary to strip the aluminum layer - but how to do this if it is between the layers of plastic and not outside?

For this, there is a special trimming tool that allows you to remove aluminum foil precisely between the layers.

The cutting edges, which “scrape out” the foil, are shifted towards the center of the product. Thanks to this, the aluminum is removed, the plastic remains in place - the pipe is ready for welding.

The photo shows what the joint looks like between prepared (right) and unprepared (left) fragments. It is clearly visible that in the first case the adhesion turned out to be dense, in the second the delamination is clearly visible. With short-term use, this defect does not matter, but for pipelines through which hot water is supplied (from a boiler or heating boiler), depressurization and failure of communications is possible.

The diagram demonstrates the consequences of a loose joint between two seemingly welded pipes, delamination of the product and swelling of the outer layer of polypropylene during operation.

Important: fiberglass reinforced pipes do not need to be stripped! This is due to the fact that the welding temperature adopted for polypropylene allows glass fiber to melt to the point of diffusion.

Correct cut

Sometimes users think that cutting the pipe obliquely - at an angle of 45 degrees - can increase the contact area and thereby strengthen the weld. This is actually true, but with this type of pruning problems arise:

• with the alignment of parts - it is difficult to correctly connect the pipe sections inside the coupling, a gap inevitably arises;
• with heating of the welded areas - an oblique cut does not allow the required fragment of the product to be completely placed on the heating element. One edge heats up less, the other more.

The last node is not welded!

This happens if an inexperienced welder inaccurately calculated the lengths and locations of pipeline fragments. When it is not possible to insert a mandrel with nozzles and a coupling between the last two elements to be welded, you can solve the problem differently - weld metal inserts into the elements to be joined.

Such a threaded pair with a union nut allows you to firmly and efficiently fasten two fragments and at the same time weld it in without any problems.

Wouldn't you, priest, chase something cheap...

An attempt to save money when purchasing pipes and fittings is fraught with leaks and swelling of pipes in the future, so it is better to purchase products from trusted manufacturers.

It is also necessary to avoid combining products from different companies - a slight difference in the composition or production technology of goods sometimes leads to critical problems in finished communications.

Other errors

Among the most “popular” errors are often found:

• excessive heating of elements. As a result, the pipe is severely deformed and closes the lumen of the coupling, thereby interfering with the free flow of water in the water supply system;

• refusal to degrease surfaces and/or clean them. In this case, diffusion does not occur over the entire surface; “islands” remain where the plastic has not fused. The result is failure of the connection when the pressure or temperature increases;
• water has not been removed (during the repair of an existing water supply system). This can be done using a rag and a warm (not hot!) stream of air from a household or construction hair dryer;
• loose connection. This happens if the pipe is not completely inserted into the fitting or the diameters do not match.

Another common mistake made by inexperienced craftsmen is not wearing protective gloves. The high heating temperature of polypropylene MUST require hand protection, and it is advisable to use gloves made of natural materials - preferably suede. They do not restrict movement and do not begin to smolder when heated, unlike cotton ones. Rubber and rubberized gloves cannot be used!

Typical mistakes are discussed in more detail in the video “How not to solder polypropylene pipes.”