With the invention of the vinyl polymerization method in 1957, the era of use began polypropylene pipes. Due to excellent technical characteristics and low cost, they have replaced classic metal pipelines from many domestic and industrial buildings. Cold and hot water supply, heating and heating systems are assembled from them. The only difficulty is the soldering of polypropylene pipes required to connect them.
Property of polypropylene
Polypropylene is a colorless material obtained by polymerization of propylene monomer with the addition of catalysts. It is characterized by chemical resistance to various inorganic solutions of hydrochloric, acid or alkaline type. The material does not absorb liquid and has dielectric properties.
Its melting point is about 170 degrees Celsius, and its hardness is approximately 55 MPa. It can withstand exposure to cold down to -15 degrees without changing its properties, however, at temperatures below this temperature it becomes brittle.
Due to its characteristics, polypropylene has found wide application as a material for manufacturing water pipes. The polymer used for their manufacture does not harm the environment and does not require special disposal. Its excellent adhesion to metal allows the production of various types of fittings by pressing with threaded nickel-plated brass inserts.
When heated above 160 degrees polymer material softens and becomes viscous. And when it cools, it regains its hardness. This property is used when connecting various parts pipeline made of plastic. To make a permanent connection, a soldering iron (iron) is used. At the same time, to use a soldering iron for polypropylene pipes, you do not need any special knowledge.
Polypropylene
Types of pipes
Both cold and hot water can be transmitted through polypropylene pipes (PPR). Depending on the requirements for the water supply system, solid or reinforced structures are used. Reinforcement helps reduce thermal expansion.
It can be done in the following ways:
- aluminum coating on the outside of the pipe;
- adding aluminum mesh to the middle of the structure;
- reinforced using fiberglass;
- fusion of composite material with fiber fibers.
Depending on the type of reinforcement, the instructions for soldering polypropylene pipes also change slightly.
IN to a greater extent this applies to devices using aluminum. Plastic pipes are marked with the Latin letters PN and a number after them. These numbers indicate the highest pressure that a structure assembled from them can withstand. Thus, PN 20 means that the pressure in the middle of the water pipeline can reach 2 MPa.
For clarity, the technical characteristics of the types of PPR used and the features of their connection are conveniently summarized in a table:
Thus, the scope of application of polypropylene water conduits is extensive. And their resistance to corrosion and external influences, mechanical hardness, durability, ease of installation and low price make them popular. This is greatly facilitated by the ease of connecting parts of the structure, which ensures a reliable permanent connection. For comparison, installing the entire system with your own hands takes five to six times less time than using metal.
Polypropylene pipes. Types of pipes and their differences
Features of the soldering tool
In order to solder polypropylene pipes, it is not necessary to invite a professional; all operations can be performed independently. But it’s worth noting that working together is much more convenient. The tool used for making connections is called a soldering iron or iron. It is classified according to two criteria: design and power.
Despite the design differences and many brands, the operating principle of the devices is the same. Just like an ordinary iron, they have two main elements: heater and thermostat. In addition, nozzles are a mandatory attribute of soldering. They are considered consumables and are sold both together with a soldering iron and separately at retail. The nozzles are made of heat-conducting material coated with a Teflon layer on top. The nozzle consists of two elements: one with a recess, and the second with a collar. With their help, the internal and external surfaces of the pipe and fitting are heated.
The thermocouple is located in the middle of the body, to which the nozzles are screwed. For uniform heating and ease of use, their location relative to each other is coaxial. When the device is connected to a 220-volt network, the thermoelement heats up, transferring its heat to the body of the soldering iron. And he, in turn, heats the nozzles. Using a thermostat, the required heating temperature is set and maintained.
As soon as the temperature sensor detects the desired temperature, the thermal relay is activated and the voltage supply to the heater is stopped. When the temperature drops by two to three degrees, the heater is reconnected to the network.
Connection technique
In order to properly connect a polypropylene pipe, buying a soldering iron will not be enough. As in any business, experience is required, so professionals recommend that beginners first practice on samples, and then move on to welding the main structure.
Before starting work a number of preparatory operations should be carried out. This applies to both the parts being connected and the soldering device. The principle of welding is based on the melting of two parts and their subsequent physical joining with each other until crystallization. To ensure a reliable weld, one of the parts to be welded is inserted into the other to a depth of 13 to 32 millimeters, depending on the diameter of the parts. Welding of two pipes occurs through a fitting. They come in different types and sizes. Each fitting is designed for a specific pipe diameter, so you should be careful when soldering.
When using a reinforced pipe with aluminum foil, the inserted end into the nozzle must be cleared of its layer. Cleaning occurs mechanically using a special tool. But since this device is quite expensive, a hacksaw blade is often used. They use it to saw the pipe in a circle to the depth of the reinforcing layer, and then cut it off with a knife. This approach requires skill and experience.
Before welding, parts should be cut to the required length, cleaned of dirt and degreased. For this, it is allowed to use isopropyl, isobutyl or ethyl alcohol. The use of acetone, white spirit, gasoline or vodka is not allowed due to loosening of polypropylene after exposure to them.
The bushings should also be cleaned with a rag before work. Attention should be paid to the integrity of the Teflon layer; nozzles with damaged coating should not be used. Therefore, cleaning with metal objects or abrasives is prohibited. In case of severe burning, wooden scrapers are used. For ease of cleaning, it is recommended to pre-heat the nozzles a little using a soldering iron.
At the last stage of preparation, a line is marked along the entire diameter of the pipe, indicating the depth of the welded zone. This size must correspond to the depth of the fitting. Then you can start welding directly.
How to solder polypropylene pipes
Welding process
After all the preparatory operations have been completed, you can proceed to soldering. To do this, you will need to screw the nozzles of the required diameter to the soldering iron using a screwdriver. It doesn’t matter which side to place the outer part or the inner part, the main thing is to withstand their bearability.
The iron for soldering polypropylene pipes is installed on a flat surface, turned on and warmed up for 10-15 minutes. In order to solder the connection correctly, you can use the following instructions for soldering polypropylene pipes:
- 1. A table with data is studied, from which the required duration of various technological processes is taken:
- 2. Using the thermostat, the required temperature is set. This value is at least 260 0 C and largely depends on the diameter of the parts.
- 3. The parts to be welded are simultaneously put on the heated nozzles. The pipe is inserted into the groove of the inner part up to the line marked on it, and the fitting is put on the mandrel.
- 4. After a certain time, in accordance with the table above, the parts are removed from the nozzles and smoothly inserted into each other to a given depth. Once the elements are connected, they must not be rotated or bent. They should be held motionless until they harden. When joining, excess molten material is squeezed out, forming a ring around the seam.
- 5. As soon as the seam hardens, the resulting part can be released, and after the cooling time has expired, it can be used.
Common installation mistakes can be divided into several types:
- 1. Insufficiently thorough cleaning of the surfaces of the parts being soldered.
- 2. Water entering the weld.
- 3. When cutting the pipe to the required length, the cutting angle exceeds 90 degrees.
- 4. Insufficient length of pipe insertion into the fitting.
- 5. Overheating or insufficient heating of the parts being welded.
- 6. Incomplete removal of the reinforcing layer.
- 7. Failure to observe the correct joining of parts and actions associated with the subsequent attempt to correct them.
Installation tricks
Professionals achieve high quality soldered seams by impeccably following welding rules. To do this they use little tricks. First of all, when docking, it is important to maintain tolerance. It's not difficult to do this. The secret to an even axis is to apply parallel line using a thin marker or pencil on both the surface of the pipe and fitting. After melting, you just need to carefully align these lines.
To fix the soldering iron in its structure a weighted foot is used. But due to the poor quality of the nozzles or their insufficient heating, pulling the molten pipeline elements out of them can lead to the device overturning. Therefore, it is recommended to carry out welding with an assistant, whose task will be to hold the soldering iron motionless.
To ensure an even cut, special scissors are used. With their help, plastic pipes are cut accurately and effortlessly. If the cut turns out to be uneven, it can be leveled using a file. In this case, after leveling is completed, the pipe should be blown out and, if necessary, the chamfer should be removed.
When choosing nozzles, preference should be given to those made of metallized Teflon. They heat evenly and are easy to clean. For household needs A device with a power of 1.2 kW is suitable. It will be quite sufficient for welding pipes with a diameter of up to 50 mm.
Thus, you don’t need any special knowledge to solder pipes; the main thing is to follow the soldering process and follow the recommendations. At the same time, since the temperature of the soldering iron reaches high values, it is worth observing safety precautions to prevent the possibility of burns.
Polypropylene pipes- pipes assembled by diffusion welding using fittings: couplings, angles, tees, etc. The estimated service life of polypropylene pipes is more than 50 years.
It should also be noted that the service life of polypropylene pipes declared by the manufacturer is 50 years, which implies that the pipeline will be operated at normal pressure and normal temperature. That is, pipes can withstand long-term significant pressures, but the temperature of the transported liquid must be low, or, conversely, the temperature of the liquid can be very high, but the pressure must be low. At high pressure and high temperature, the service life of the pipe is sharply reduced and can reach 1-5 years. To determine the service life of pipes operating in extreme conditions, there is a special table. We will not present it in this book, since at the household level such long-term loads do not occur in home pipelines, but short-term ones emergency situations associated with a sharp rise in pressure or a sharp jump in the temperature of the transported liquid, the pipe will withstand.
Polypropylene pipes come in gray, white, black and green. Color other than black does not mean any restrictions on the use of pipes. The black color of the pipe indicates that it is most protected from ultraviolet radiation.
IN polypropylene water pipes Permanent connections are used, pipes are assembled on welded fittings once and for all.
Polypropylene pipes can be used for:
Water supply to houses: installation of risers, installation of pipes, connection of pipes to water supply networks from metal pipes
Heating a house: installing heating risers. Installation of heating pipes, connections to the boiler installation, connection to metal radiators.
The long service life of polypropylene pipes allows them to be used for laying all types of pipelines:
open gasket;
wall gaskets;
in a closed gasket;
- PN 10- thin-walled version, for cold water supply (up to +20°C), nominal operating pressure 1 MPa (10.2 kg/cm/2);
- PN 16- wiring cold water high pressure and pipelines central heating low blood pressure;
- PN 20- a universal pipe is used for cold and hot water supply (temperature up to +80°C), nominal pressure 2 MPa (20.4 kg/cm2);
- PN 25- reinforced with aluminum foil, for hot water supply and central heating (up to +95°C), nominal pressure 2.5 MPa (25.49 kg/cm-).
Unlike metal-plastic pipes, the aluminum layer in these pipes is closer to outside and, most often, there is perforation on it, which makes it possible not to use glue to fasten the layers of the pipe. The connection of the outer and inner layers of polypropylene to each other or to the aluminum layer occurs through perforated holes, which, in turn, can be through-hole or superficial from different manufacturers. The direct connection of polypropylene with aluminum significantly increases the stability and strength of the pipes.
Thanks to this connection, PN 25 pipes have thinner walls than conventional polypropylene coarse pipes and allow for greater fluid flow.
Designed for special use - mainly in heating pipelines, as well as in hot water supply pipelines, but can also be used for cold water supply systems.
They also allow you to connect a polypropylene pipeline to a metal one. The pipes are environmentally friendly and are successfully used in cold and hot water supply and heating pipelines. Thanks to fittings with chrome and brass inserts, pipes can be easily combined with existing steel fittings and plumbing fixtures.
Fittings used for connecting polypropylene pipes
Connection fittings
Used to connect 2 or more polypropylene pipes.
Main sizes: 20 x 1/2, 20 x 3/4, 25 x 1, 32 x 1, etc.
Fig.1. Coupling for connecting polypropylene pipes of the same diameter;
Fig.2. Coupling for connecting polypropylene pipes of 2 diameters;
Fig.3. Angle 45°;
Fig.4. Square 90°
Fig.5. 45° elbow for connecting pipes different diameters;
Fig.6. 90° elbow for connecting pipes of different diameters;
Fig.7. Triple square;
Fig.8. Tee with identical fittings (connection of pipes of the same diameter);
Fig.9. Transition tee (connection of pipes of the same diameter);
Fig. 10. Crosspiece;
Fig. 11. Plug for polypropylene pipes;
Fig. 12. Thermal expansion compensator;
Threaded fittings for polypropylene pipes
Rice. 1. Transition (coupling) with internal thread;
Fig.2. Transition (coupling) with external thread; 
Fig.3. Transition (coupling) with transfer nut; 
Fig.4. Transition (coupling) with a transfer nut and a metal insert; 
Fig.5. Transition with external plastic thread type “DG” 
Fig.6. 90° elbow with internal thread; 
Fig.7. 90° elbow with external thread; 
Fig.8. 90° elbow with changeover nut;
Rice. 9. Tee with internal thread; 
Fig. 10. Tee with external thread; 
Fig. 11. Tee with switch nut; 
Fig. 12. Water socket angle for fastening the mixer and other appliances: 20 x 1/2, 25 x1/2; 
Fig. 13. Set of water sockets for mixer: 20 x 1/2, 25 x1/2; 
Fig. 14. Fitting with transfer nut; 
Fig. 15. Welded seat with internal thread; 
Fig. 16. Welded seat with external thread; 
Fig. 17. Collapsible connection; 
Fig. 18. Dismountable connection with internal thread; 
Fig. 19. Dismountable connection with external thread;
Welding (soldering) of polypropylene pipes
For welding pipes with a diameter of up to 63 mm, the preferred type of connection is socket or socket welding. In this case, the connection of two pipes occurs using a third part - a coupling, and the creation of threaded and other connecting units occurs using fittings with a socket.
For welding pipes with a diameter above 63 mm, butt welding is recommended as it does not require additional parts and is the most reliable. If there are fittings of the appropriate diameter, sleeve welding is allowed. The recommended type of collapsible connection for diameters greater than 63 is a flange joint. It's more difficult option connecting polypropylene pipes requires professional equipment and skill, so this option is omitted in this article.
Socket welding
When welding pipes with diameters up to 40 mm, you can use a manual welding machine; when welding pipes with diameters over 40 mm, it is recommended to use machines with centering devices. When using centering devices, follow the instructions for their use.
To connect polypropylene pipeline parts, welding machines with special nozzles are used.
Fig.1. Welding machine for welding polypropylene pipes.
The heating elements (nozzles) are a sleeve for melting the outer surface of the pipe end and a mandrel for melting the inner surface of the socket of the connecting part.
Standard nozzles are coated with non-stick material - Teflon, and have diameters from 16 to 40 mm. During operation, it is necessary to monitor the cleanliness and integrity of the Teflon coating. After each welding episode, while they are still hot, the nozzles are cleaned with a canvas rag or wooden scrapers. In a cold state, cleaning the nozzles from the adhering layer of plastic is unacceptable.
Fig.2. Nozzles for welding polypropylene pipes with a diameter of 20, 40, 32, 40, 50, 63.
The welding machine is installed on a flat surface and replaceable heaters of the required size are secured to it using special keys. It is advisable to install the entire required set of nozzles (see Fig. 3) on the device’s seats before heating the device.
Fig.3. Welding machine before heating with installed nozzles for welding polypropylene pipes.
From the point of view of heating uniformity, the location of the nozzle on the heater does not matter. Therefore, the nozzles are placed in a way that is convenient for installation. Closer to the end, place the nozzles necessary for working on the wall, that is, on the pipeline branch being mounted.
The quality of connections directly depends on the convenience of performing technological methods, therefore, it is better to assemble all pipeline fragments that can be mounted on a permanently installed device (on a stand) separately.
It is advisable to carry out welding “on the wall”, especially in inconvenient places, with an assistant.
The welding temperature for polypropylene pipes is set on the machine - 260 ° C and 220 ° C for polyethylene and PERT pipelines).
Depending on the temperature environment heating lasts 10-15 minutes.
The operating temperature on the surface of the heating plates is achieved automatically.
Welding of polypropylene pipes and fittings is prohibited at temperatures below 0°C. The air temperature during welding is very important. So the welding time must be increased at low air temperatures and reduced in hot conditions.
General rule for socket welding
The inner diameter of the unheated fitting should be slightly smaller than the outer diameter of the pipe.
Socket welding of plastic parts to each other is carried out as follows.
1. Use scissors or a pipe cutter to cut the pipe at a right angle.
2. If necessary, clean the end of the pipe and the socket of the fitting from dust and dirt, degrease with alcohol or soapy water and then dry.
When welding PN 10 and PN 20 pipes, nothing else needs to be done at this stage.
When welding reinforced pipes PN 25 with a special tool using a shaver, the two top layers of polypropylene and aluminum are removed from the pipe. The size of the fitting socket is made in such a way that only a pipe with the top layers removed can fit into it. The depth of stripping is carried out according to the stop of the tool, which determines the depth of welding.
Fig.5. Shaver
Fig.6. Processing the pipe with a shaver.
3. Apply a mark to the pipe at a distance equal to the depth of the socket plus 2 mm. If you use rough parts, fittings and tools from the same manufacturer, then, most often, you don’t need to do any calculations. The shaver (Fig. 2) removes the upper layers of the pipe exactly to the welding depth, and the dimensions of the heating nozzles are such that it is impossible to insert a pipe into them to a depth greater than required.
4. Place the parts to be joined on the appropriate nozzles: insert the pipe into the sleeve up to the mark indicating the welding depth, and put the socket of the fitting on the mandrel.
5. Maintain the heating time (see Table 1), then remove the parts from the device and connect them to each other without turning the parts along the axis. Welding fittings must be connected to the pipe with a quick, confident movement, maintaining the alignment of the pipe and coupling. The connection between the pipe and the fitting must occur to the depth determined by the boundary inside the fitting socket.
6. After welding, it is necessary to maintain a cooling time, especially for thin-walled pipes. Rotation and bending (deformation) during cooling are not permitted. Connection with poor alignment or angle relative position fittings are subject to only one method of correction - the incorrectly connected fitting is cut out. You must be especially careful when welding elements for which position is important - angles, tees, ball valves. The latter must be welded so that the handle can move freely to all positions.
If you are soldering (welding) polypropylene pipes for the first time, you can cut the first connection to check, it should look like this:
The welding machine must be constantly switched on during the entire welding process. Heating begins simultaneously for two parts.
If underheating occurs, there is a possibility that the parts will not reach the temperature of viscous plasticity. In this case, the connection will be unreliable and diffusion of the material may not occur.
When overheated, there is a possibility of loss of shape stability, the adhesion (stickiness) of the material will be excessive. It will be impossible to insert the pipe into the fitting, and as the force increases, the edges of the pipe will bend inward or become wrinkled. The connection will be narrowed.
The outer surface of the connecting part welded to the pipe should not have cracks, folds or other defects caused by overheating;
At the edge of the socket of the connecting part welded to the pipe, a continuous bead of melted material should be visible around the entire circumference, protruding beyond the end surface of the connecting part.
Instructions for welding welded seats
Welded saddles are used for installation of subsequent branches from the pipeline during the repair of existing systems.
First you need to drill the wall plastic pipe Fusiotherm drill.
When using combined Stabi pipes, remove any remaining drilled hole aluminum using the Fusiotherm chamfering tool.
Fig.1. Drilling a hole in the pipe wall.
The welding device/saddle welding tool must achieve the required operating temperature 260°C.
The surfaces to be welded must be clean and dry.
Fig.2. Installation welding machine;
The heating connection of the weld-in saddle tool is inserted into the hole in the wall of the plastic pipe until the tool reaches completely outer wall pipes. The welded seat fitting is then inserted into the heating sleeve until the surface of the seat reaches the crown of the tool. The heating time of the elements is 30 seconds.
Fig.3. Heating of the pipe and seat.
After removing the welding tool, the welded seat fitting is quickly inserted into the heated hole. Then the seat should be pressed accurately and tightly, without rotating, onto the heated outer surface of the plastic pipe.
Fig.4. Installation of a welded seat;
The welded seat is fixed motionless on the pipe for 15 seconds. After 10 minutes of cooling, the connection can be subjected to full load. The corresponding branch pipe is welded into the coupling in the usual way.
Fig.5. Finished welded seat.
Examples of finished polypropylene pipelines welded by socket welding
The simplest example of polypropylene pipes in a bathroom:
The simplest example of polypropylene pipes from a toilet to a bathroom) Please note that the polypropylene pipeline is removable).
Piping made of polypropylene (a more complex option), all pipes are wrapped in thermal insulation to prevent the formation of condensation for cold water and reduce heat loss for hot water).
In conclusion, I would also like to indicate the thermal expansion coefficients of metal-plastic pipes and polypropylene pipes:
For metal-plastic pipes (PEX-AL-PEX) = 2.6 *10 -5
For metal-plastic pipes with a reinforcing layer of ethylene vinyl alcohol (PEX-EVOH-PEX) = 2.1 * 10 -5
For polypropylene pipes, without reinforcement (PP) = 15 * 10 -5
For polypropylene pipes with an aluminum reinforcing layer = (PP ALL-PP) = 3*10 -5
Well, a little clarity in these numbers:When the ambient air temperature, or the temperature of the liquid inside the pipe, changes by 10 degrees Celsius, each meter of pipe will lengthen or shorten, respectively:
PEX-AL-PEX = by 0.26 mm
PEX-EVON-PEX = 0.21 mm
PP-ALL-PP = n 0.3 mm
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.
Species
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 attention special attention on 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 that has an outer reinforced layer.
Pay attention! 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.
Pay attention! 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
Welding polypropylene is one of the ways to connect water and sewer lines. In this case, hermetic joints are obtained, since the products are cross-linked at the molecular level. If soldering of polypropylene pipes is done correctly, the service life of the water supply or drainage system increases many times over.
Specifics of soldering polypropylene pipes
Welding of polymer products is carried out using technology, which is realized through the use of material properties. Polypropylene is flexible. However, PP products acquire this property when the temperature changes. Its increase to a certain level helps to soften the material.
Cooling of a heated pipe joint also occurs quickly. For this reason, soldering/adhering time is reduced. If you perform actions to connect communications slowly, the quality of the connection decreases. In this case, it is difficult to ensure the tightness of the seam.
Welding of polypropylene pipes is possible due to the properties of this material. Melting point – from +149°С. Soldering irons are used for soldering polypropylene. They provide heating of PP products to a level of +320°C, but at home a less intensive operating mode is used (up to +300°C).
PP pipes must not be exposed to a heat source heated to critical temperatures. It is also not recommended to use a soldering iron on the pipe for too long. Under such conditions, the material loses its properties, and the product will become wrinkled as a result.
General description of technology
The process of welding PPR pipes is called polyfusion.There are 2 methods of recording communications:
- coupling;
- butt.
The first technology for welding polypropylene pipes with your own hands is more suitable for beginners, because it requires less skill. The work can be completed even if the pipeline has not been installed in this way before.
Coupling soldering: 1 – polypropylene pipe, 2 – coupling, 3 – heated part of the soldering iron, 4 and 5 – nozzles (blanks) The coupling method is based on the need to use special connecting elements that completely encircle the end part of the communications. Inside the coupling there is a connecting seam of 2 products. For water supply in living conditions This installation method is more suitable.
If it is not possible to use a shaped part, you can make a semblance of it. To do this, use a straight section of communications and trim it. Take into account that products are inserted into the fitting from 2 sides to a certain depth. The coupling method is used for joining communications with a diameter of up to 63 mm.
Direct soldering: 4 – heated soldering iron pancake, 5 – area of the plastic pipe undergoing melting. The direct fixation method requires heating only the end sections of the pipes. In this case, a fitting is not used, the seam connection is not closed with anything. This technology is used for welding large-diameter polypropylene pipes; it is rarely used in everyday life.
The disadvantage of this option is the difficulty of correctly positioning communications in accordance with the axis. Even small deviations to the sides can slow down the flow of fluid through the pipeline. For direct installation, a centering system is additionally used.
Tool for installing polypropylene pipes
| Photo of the instrument | Name |
|---|---|
| welding machine, for work at home it is recommended to use units designed for welding PP pipes of small and medium diameter - up to 63 mm. |
| The pipe cutter is an ideal device for cutting polypropylene. |
| Shaver - designed to remove a layer of reinforcement. |
| A trimmer is needed for high-quality pipe joining |
| Marker for marking pipes. |
| Using a building level and a pencil, draw the direction of the pipes on the wall |
| A tape measure is one of the main tools in construction. |
| A degreaser is needed to remove impurities from the surfaces of welding joints. |
A soldering iron can be purchased or rented. You don’t always have a trimmer or shaver at hand. However, these tools will be needed to work with reinforced pipes. So, the shaver is designed to remove reinforcement. Its knives are located parallel to the axis of the pipe. Thanks to this, the middle layer of communications is removed. The trimmer is used to prepare pipes and remove the reinforcement layer. Such a tool processes the end; in addition, it creates a chamfer.
When studying information on how to properly solder polypropylene pipes, you need to take into account what is first compiled in an apartment or private house. This must be done to calculate the amount of materials and determine the exact length of communications.
A marker and tape measure are used to mark. Moreover, it is necessary to determine not only the places for cutting products, but also the areas that will be inserted into the nozzles of the welding machine
Soldering machines for pipe welding
Such devices are designed quite simply. Main nodes:
- temperature regulation and control unit;
- handle for fixing the device;
- support to avoid direct contact between the surface on which the welding machine is installed and the heating element.
The kit includes nozzles that differ in diameter, as well as gloves and small tools. The equipment varies depending on the model of the device. The wider it is, the higher the price.
Types of soldering irons for polypropylene
There are manual and mechanical soldering irons. However, in everyday conditions the first option is used. This is due to the simplicity of the design, ease of operation, and small dimensions.
Do-it-yourself soldering of polypropylene pipes is done using 2 types of devices:
- sword-shaped soldering iron;
- cylindrical.
Soldering irons differ in the shape of the heating element. There are several holes on the plate of sword-shaped devices, which allows the installation of various attachments, which consist of 2 parts: a mandrel and a sleeve. They are designed to heat the end sections of communications. So, a connecting element is mounted on the mandrel; the sleeve is designed to heat the end section of the pipe.
Heating of products using nozzles must be carried out simultaneously. When studying the question of how to weld polypropylene pipes, it is necessary to use devices that include Teflon-coated nozzles. This prevents the molten material from sticking to the metal.
Cylindrical devices differ in design from sword-shaped ones, which is due to the presence of a heating element in the shape of a cylinder. In this case, crimp-type nozzles are used. They are put on a metal cylinder and firmly fixed. On both sides of such nozzles there is a mandrel and a sleeve. The soldering principle is the same as in the case of the sword-shaped analogue.
Criteria for selecting welding machines
- Power. To work with communications with a diameter of no more than 75 mm, you should purchase a device with a power of up to 1000 W. Its capabilities are sufficient to ensure high quality seams. However, in everyday life, the soldering method is more often used to fix pipes with a diameter of up to 50 mm. In this case, units with a power of up to 700 W can be used. Moreover, you need to remember that the starting currents when turned on are much higher, so a power reserve (20-30%) must be provided.
- Type of heating element: plate, cylinder. In everyday life they use the first option; it is easier to work with. This is important if you have no experience in installation work of this type.
- Number, type and size of nozzles. Determine which products need to be soldered. The diameter of communications is taken into account. The simplest models provide the ability to simultaneously solder 2-3 pipes and even more, the same number of fittings. In this case, the heating element has 2-3 holes.
- Manufacturer.
On construction market production equipment can be found different countries: Russia, China, Turkey, Czech Republic. The latter option is more expensive; such devices are distinguished by high build quality and reliability. Welding machines may have errors when measuring temperature. As a result, the actual indicator often does not correspond to the target one.
Czech technology wins according to this criterion; the error of such soldering irons is minimal. However, in everyday life, beginners should use Russian or Chinese models, since they are cheaper, although they have a significant error, which for some models is 10°.
How to solder polypropylene correctly - instructions
You need to act consistently, in this case the likelihood that a mistake will be made is reduced.
Step by step instructions for soldering polypropylene pipes Soldering instructions:- Preparing the room. Considering that during soldering they are released toxic substances, ensure efficient air circulation.
- After cutting, the edges of the communications are processed with a trimmer or chamfer. They make chamfers, this makes it easier to join the pipes.
- The materials are degreased: cleaned of dust, treated with white spirit. You need to continue working when the surface is completely dry.
- Turn on the soldering iron, having previously set the temperature to the required level (+260°C).
- When the green light on the body of the soldering iron lights up, you can proceed to soldering. A pipe is installed in the sleeve nozzle, and a fitting is placed on the mandrel.
- At the same time, 2 elements of the future pipeline are heated: a fitting, a pipe.
- After waiting the time indicated in the table above, the pipe and the shaped element are removed from the nozzles and joined to each other. In this case, the parts must be held motionless. Communications are connected to a previously drawn longitudinal line. The slightest displacement of polypropylene that has not yet hardened will lead to the destruction of molecular bonds. This may cause a leak in the future.
Soldering table for polypropylene pipes
The heating and holding time of PP pipes at a given soldering iron temperature allows us to ensure high quality seam connection. Low heating will not allow softening of communications. In this case, it will be impossible to join the pipes.
Connecting pipes by soldering with reinforcement
The operating temperature of communications for cold water supply varies within -10…+90°C. Under the influence of the coolant, the pipeline bends, as intense linear expansion occurs. This means that for heating you need to use pipes that have more suitable characteristics.
1 – cut off the required length of pipe. 2 – remove the reinforcement with a seamstress. 3 – direction marking. 4 – heating of the pipe and fitting. 5, 6 – connecting the pipe with the fitting and fixing it. So, under conditions of influence high temperatures Products reinforced with fiberglass or aluminum are used. Such pipes are multilayer products: a thin layer of fiberglass is applied on top of the polymer product and covered with a layer of PP. Advantages:
- relative stability of linear expansion, even under the influence of high temperatures the geometry of the product changes slightly;
- ability to withstand pressure up to 10 atm, for comparison, in apartment buildings communications are subject to less intense influence (6-8 atm);
- due to the presence of a reinforcement layer, the service life of the pipeline increases;
- pipes with internal reinforcement are resistant to high temperatures, at which the classic version of communications begins to melt.
The technology for soldering reinforced pipes does not differ from the method of joining unreinforced communications with the only exception: on preparatory stage The ends of the products must be cleaned of the reinforcing layer, for which a trimmer or shaver is used. After preparation, the pipes are degreased, then heated with a soldering iron and connected.
Rules for soldering PCB to avoid mistakes
- The diameter of the polypropylene pipe is selected;
- before work, prepare everything necessary, since welding is performed quickly, there will be no time for preparation during the installation process, the soldering iron is turned on when the communications are already cut;
- The welding machine must be securely fixed to horizontal surface, the quality of the seam will depend on this, such units are equipped with special stands, but some models are not installed firmly, so they need to be additionally secured;
- The melting point of polypropylene is much less than value, which is set in the settings of the welding machine, this difference is due to the need to quickly soften the pipe; a temperature of +260°C is considered sufficient;
- should not be changed temperature regime when using larger products, when soldering PP pipes, the heating temperature does not change with increasing diameter of communications; from the table above you can find out that the dimensions of the products only determine the duration of heating of the material;
- you need to navigate by the indication: a red light indicates that it has turned on heating element, green – indicates that the set temperature value has been reached;
- Often users skip the stage of degreasing the material, however, the presence of dust or drops of water in the cut area can cause the seam to weaken, since in this case the structure of the material becomes more porous;
- when installing a pipeline of complex configuration, it is necessary to connect the pipes at different angles, they are also rotated relative to each other; in order not to disturb the alignment of the products, it is recommended to first determine the exact position of the communications, then perform their preliminary installation (without using a soldering iron), at this stage you need to draw a marking strip along the center line through the 2 parts being connected.
It should be taken into account that thin-walled pipes warm up faster. This means that the period of operation of the soldering iron is reduced by 2 times. If you are studying the question at what temperature to solder such pipes, you need to remember that the value of this parameter does not depend on the dimensions of the product. Thin-walled communications are connected to each other at the same temperature as thick-walled ones.
Impact of errors on welding quality
This is what happens if you solder PP pipes incorrectly! The most common violations technological process rations:
- surfaces are not degreased, resulting in a decrease in the quality of the seam joint;
- The cut angle of the pipe and fitting does not correspond to 90°;
- insufficient deepening of the pipe into the fitting or, conversely, communications are brought into the shaped element all the way, as a result, a large seam is formed inside, which impedes the flow of liquid;
- violation of the heating technology: the pipes were on the nozzles for too little or, conversely, a lot of time, in both cases the quality of the seam joint will be low;
- when connecting reinforced pipes, the reinforcement layer at the end section was not completely removed, as a result, this material will prevent the melting of polypropylene, such a seam will be weak, or it will not be possible to make it at all;
- after joining, the position of the parts was adjusted, which led to a decrease in the reliability of the seam; To avoid such consequences, you should wait a while after connecting the pipe and fitting, ensuring that the parts remain stationary. Method with gas burner less preferable.
If a torch is used, it will not be possible to heat the polypropylene evenly. As a result, the seam joint will look sloppy, in which case the reliability of the seam is reduced. Over time, a leak may appear in this area. This method can be used as a last resort and only when installing cold water supply systems.
Connecting a pp pipe with a compression coupling The compression coupling provides a reliable connection of communications and is used as a complete replacement for a welding machine. However, the cost of such an element is high. As a result, costs will increase, since pipes throughout the entire room will need large number compression fittings.
Method for gluing polypropylene pipes. Method cold welding also effective. In this case, a two-component epoxy composition is used. This material allows you to obtain a reliable connection without special equipment.
To fix the communications, you need to apply an adhesive substance to the cleaned and degreased surfaces of the products. Then the pipe and fitting are joined, holding tightly. The glue sets within 10 minutes. It takes 1 hour to completely harden. This option can only be used when installing a cold water supply system.
Conclusion and useful video about soldering polypropylene
When soldering polypropylene communications, you need to properly prepare the material (mark it, cut it), and tools. Work is performed sequentially. For example, if you skip the degreasing step, the seam will not be reliable enough.
Video instructions for soldering polypropylene pipes:
It is important to follow the rules for heating and joining pipes, otherwise, after putting the pipeline into operation, it may be necessary to repair it. You can learn about the intricacies of soldering from the video.
Plastic pipes, due to their affordable cost and ease of connection, have taken a leading place in the installation of water supply and heating networks. Despite the fact that such structures are less strong and not as durable as metal ones, many people prefer them when they plan to change engineering communications your home. First of all, everyone is attracted by the speed of installation work, since soldering polypropylene pipes provides an excellent opportunity to make a fairly strong and strong connection in a short period of time.
Classification of polypropylene pipes
A fairly durable plastic that is used for the production of pipes that are resistant to corrosion. They are resistant to salt deposition and accumulation limescale. Polypropylene structures are used for long-term use. The service life is at least 50 years. This is actually a very realistic period, provided that such pipes are used directly in places corresponding to their conditions of use. All parts are designed to withstand long-term exposure to high pressure at low temperatures. All pipes of this type are available in four colors. But their color does not in any way affect their scope of application and quality of work. Polypropylene pipes are primarily intended for water supply and heating systems. In some cases, it is possible to combine them with metal structures. Use is possible in pipelines of any type - open, closed and wall.
Advantages of polypropylene pipes
Polypropylene pipes have an unlimited number positive points, compared to other types of materials. They are not subject to corrosion and the appearance of fungus. They have a long service life. For these reasons, plastic products have a wide range of applications, both in industrial, household, and repair work.
To install polypropylene pipes, a special soldering apparatus is required. Any connection of a plastic pipe with water supply elements is carried out using special connecting parts. Let's take a closer look at how to professionally solder plastic pipes.
Heat resistance of polypropylene pipes
In order to thoroughly master the instructions and rules for working with any material, you need to be well aware of all its characteristics and properties. The first thing you should pay attention to about plastic pipes is its heat resistance. Any plastic product loses all its abilities at temperatures of 140 degrees and above. Therefore, the manufacturer always indicates the maximum temperature range. For unreinforced pipes, this figure averages 95 degrees.
First of all, you should pay attention to the type of pipes purchased for heating systems and water supply systems hot water. Reinforced pipes, which combine the qualities of metal and plastic structures, have high heat resistance.
There is another important point that is worth paying attention to - this is the maximum permissible pressure in the pipe. All numbers are always indicated by the manufacturer.
Thermal elongation process of polypropylene pipes
Thermal elongation is a measure of change linear size during heating. During strong heating, a long and straight section of pipe will begin to become covered with waves and sag. It is not recommended to use one section of pipe to install a heating system or supply hot water from floor to floor. Otherwise, tension may form, which will subsequently lead to deformation of the pipe and major problems.
Instructions: how to solder heating pipes correctly to avoid troubles
1. First of all, you need to use pipes with a reinforcing coating. The pressure coefficient of this material is five times lower compared to reinforced pipes. Also the permissible pressure value is higher.
2. Use expansion joints in such a way that the pipe is bent in the shape of the letter “P”. Since in this case the legs of the bend will begin to move closer together, the elastic plastic will remain straight when extended.
Experts advise using both methods for installation work on the heating system.
Reinforced polypropylene pipes
Reinforced pipes are products with a rigid frame made of fiberglass or aluminum. The aluminum reinforcing layer is located either at the top or between the plastic layers. Layers hold together special glue. In this case, the size of the aluminum layer varies from 0.1 to 0.5 mm. Fiberglass reinforcement is done differently. In this case, the layer is located directly in the center, and the pipe itself has the appearance of a monolith, where the layers are firmly welded to each other.
The reinforcing layer affects not only the characteristics of the pipe, but also the method of soldering it. The installation work of a reinforced pipe is practically no different from the installation of unreinforced structures. But there is still a slight difference - a pipe with an external reinforcing layer of aluminum must be protected with a special tool - a shaver. Interior The product is protected by a trimmer.
Without coating, reinforced pipes are much more expensive, so it is not wise to use them for installing cold water supply. For cold water lines, standard polypropylene pipes are quite suitable.
Types of pipes and fittings
Polypropylene pipes are usually divided into 4 main categories:
1. Thin wall part PN10 is used for heated floor and cold water supply system. In this case, the pressure indicator has a value of 1 MPa, the permissible temperature varies from -45 to 20 degrees.
2. Product PN16 is intended for installation work in heating systems with low pressure and cold water supply systems. In this case, the pressure indicator has a value of 2 MPa, the maximum permissible temperature level is 80 degrees.
3. The universal product PN20 is used for installing cold and hot water supply. The pressure indicator is 2 MPa, the maximum permissible temperature is 80 degrees.
4. The product for installing cold and hot water supply PN25, is equipped with internal aluminum reinforcement, the pressure indicator is 2.5 MPa, the maximum permissible temperature is 95 degrees.
To connect polypropylene pipes with other steel products, it is customary to use fittings with brass or chrome inserts. There are several main types of fittings:
1.For products of the same size, but different diameters, solder couplings are used.
2.For products of different and identical diameters, angles of 45 and 0 degrees are used.
3. For products with the same diameter, a tee and a triple angle are used.
4.Plug.
5. Soldering made of polypropylene.
6. Cross
7.Combination couplings with different types threads.
Required set of tools
To solder plastic pipes, it is customary to use special soldering equipment. Such a machine can be bought at any hardware store. The most simple models have a power of up to 800 W. This power is enough to install the necessary communications in a private house or apartment. As for professional soldering irons, they have temperature regulators. The power of the device does not have any effect on the quality of soldering; it is only intended to determine the rate of heating of the material to the desired temperature.
The set includes a standard soldering iron, for polypropylene pipes included, nozzles have a diameter of 20, 25 and 32 mm. These sizes are suitable for couplings, various connections and standard pipes. All attachments are an integral part of the heating component. The nozzles have a sleeve that promotes melting of the outer part of the pipe and a mandrel designed for the internal surfaces of the materials being joined. It would be ideal if the nozzles were Teflon coated. This coating serves as excellent protection against the negative effects of molten plastic. It also greatly facilitates the process of removing the molten pipe and improves the quality of welding.
The soldering iron is necessary tool, which is designed for laying polypropylene pipes, but in addition to the soldering iron, you will need another set of tools:
1. To measure the required pipe size, you need a tape measure.
2.To mark walls and pipes you need a pencil.
3. A hacksaw for metal if there is no knife for a plastic pipe.
4. Sharp knife.
5.For reinforcement inside the pipes - a trimmer.
6. For reinforcing the outer part of the pipes - a shamer.
Much attention is paid to installation work pipe cutting The best tool in this case is considered to be specialized scissors made of durable steel. Using them you can cut pipes exactly at an angle of 90 degrees. This will help save a lot of time and make the cutting process easy and simple. Recently, manufacturers have begun to include such scissors in soldering kits, so when purchasing equipment you need to pay attention to its contents.
Rules for using a soldering iron
2. On an installed soldering iron, assemble individual parts of the pipeline. For ease of work, it is advisable to involve an assistant in the work.
3. Work begins only after the soldering iron has heated to the desired temperature. It only takes 10-15 minutes for it to heat up to 260 degrees.
4.During soldering work The soldering iron is not disconnected from the network.
5. The parts to be joined must be heated at the same time.
6. Remains of plastic are removed using a tarpaulin rag.
Before starting work, turn on the soldering machine. Standard mechanisms have two main indicators - the device is turned on and the thermostat. The indicators do not go out while the device is heating up. After 10-15 minutes the thermostat indicator will go out. This indicates that the soldering iron has heated up to the desired temperature and is ready for use. Considering that during operation, the soldering iron consumes a lot of electricity, in this case it is better to wait restart soldering iron, and after that you can start working. A pipe is taken and the required length is measured. The length should be taken with a margin, since you need to take into account the depth of the nozzle and fitting. The designated pipe size is cut with scissors or a hacksaw. After this, you need to select the fitting size. Its internal diameter in an unheated state should be greater than the diameter of the pipe. The fitting and the outer part of the pipe are cleaned of dust and rendered harmless with a soap solution, and then thoroughly dried. All parts are installed on the required soldering iron attachments. The pipe is inserted inside the sleeve, and the fitting is put on the mandrel. All diameter values are determined according to the table below:
|
Pipe diameter, mm |
Belt width, mm |
Heating time, sec |
Connection time, sec |
Time for solder cooling, min |
Then all the necessary parts are removed from the soldering iron and connected to each other without turning along their axis. This needs to be done with little pressure. The pipe is inserted into the fitting to its entire depth. After the plastic has completely hardened, all connections become reliable and durable.
If a continuous bead appears at the edges of the bell along the entire circumference, this indicates that the connection has been completed correctly. Do not turn the pipes while maintaining the cooling time. If the connection has formed an angle or is misaligned, it must be cut off and all the work done again.
Distinctive points of soldering reinforced pipes:
1. The outer side is chamfered and the reinforcement is protected using a shaver.
2. If the pipe is reinforced with aluminum in the upper part, then it is simply installed in the stripper and made several turns.
3. If the reinforcement was internal, then the reinforcing layer is strongly pressed against the facing tool and rotated.
To determine exactly how to professionally solder polypropylene pipes, it is necessary to indicate that in this work the most important thing is to act confidently and quickly, and also to monitor the correct ratio of parts. If you are soldering pipes for the first time, it is better to first make several test connections. This will allow you to control the quality of the work performed. To do this, the control sample must be cut lengthwise. During work, great attention should be paid to corners, taps and tees. The faucet handles must move without obstacles to any position and in no case rest against the pipe. In addition, safety precautions must be observed, since the work is carried out at high temperatures. Chamfering the pipe is simply necessary. Otherwise, the softened plastic will be pulled up during soldering and, as a result, the connection will be less strong. The pipe must be inserted into the fitting until it stops. Then a pipe is welded to it along the entire length at the end. This point is very important, first of all, for products with an internal reinforcing layer.
Teflon nozzles must not be cleaned of plastic residues using metal objects. Residues are removed with a rough cloth.
Thus, we have considered the entire process of soldering polypropylene pipes and all important points in this process. After reading this article, you can try yourself in this matter.