Plastic water pipes made of polypropylene are becoming more and more popular, including because the installation technology is very simple and accessible for independent execution.
But for this you need to know how to properly solder polypropylene pipes, because this is the main operation that determines the durability of the entire system.
Installation of plastic pipes for internal wiring is a fairly simple, but quite labor-intensive process, therefore, first of all, you need to understand how to properly solder polypropylene.
Properties of polypropylene
Water supply products are made from PPR plastic with the following characteristics:
- operating temperature range from -10 to +90 degrees;
- plastic melting begins at 149 degrees;
- nominal pressure from 1.5 to 2.5 atmospheres.
One of them is to reinforce the walls with fiberglass or aluminum. To do this, a layer of fiberglass or aluminum foil is placed on top of the finished pipe, and then another layer of polypropylene is applied.
This design makes it possible to obtain polypropylene pipes suitable even for use in heating and hot water supply systems.
The fundamental way to reinforce polypropylene products is to install a metal layer. For this, aluminum foil in the form of a strip is used.
It is wound along a helical line onto the workpiece along a layer of glue, and a second adhesive layer is applied on top of the metal foil. The outer shell is made of the same polypropylene.
Such products are suitable for use in water supply systems with high pressure up to 6 atmospheres.
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.
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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.
Equipment for installation of polypropylene
Polypropylene water pipes have their own characteristics in terms of assembly technology, determined by the properties of the source material. Before soldering polypropylene pipes, you need to purchase a special tool for this.
Its set is not very extensive, but it contains some devices that are used only for this process:
Scissors for cutting polypropylene products. They are needed to ensure a strictly perpendicular cut. If a gap is formed at the interface during soldering, there is a possibility of a violation of the tightness of the connection.
Shaver is a device for cleaning the surface of products before soldering. Without this device, soldering is generally impossible. polypropylene pipes, reinforced with any materials. The fact is that soldering polyethylene is a diffusion process in which mutual penetration of the molten material occurs.
Naturally, aluminum or fiberglass are unsuitable for this purpose. Using this tool, you can also chamfer at an angle of 45 degrees at the ends of the parts to be joined to facilitate joining during the soldering process.
There are many design solutions for this device, so when purchasing a tool, a wide choice is provided.
Soldering iron. The main tool used for soldering polypropylene water pipes. Its basis is a plate on which replaceable bushings are attached various sizes. These nozzles are paired - one for the fitting, the second for the pipe.
The parts to be connected are installed on a replaceable tool. Switching on is done on the handle of the device, where the temperature regulator is also installed. The heating time of the mating parts is 6 seconds or more.
Typically, the tool kit also includes a screwdriver for installing a replacement tool, a marker for marking, and a tape measure for taking measurements.
Preparation for installation of water supply from polypropylene pipes
It is safe to say that high-quality preparation for wiring assembly largely determines its performance and durability.
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In addition, one of the main tasks of these activities is to calculate the real need for water supply elements.
Selecting a connection diagram
Currently, two main schemes for installing pipework are common:
Tee– with it, each water consumer is connected to a central pipe connected to a riser. Tees are used for this.
The disadvantage of this scheme is the fact, that with the simultaneous opening several taps, the pressure in the supply pipe decreases sharply and the flow of water in each of them decreases. Parsing points remote from the riser are especially affected.
The second negative point is that when the need arises for current repairs the entire water supply system has to be turned off during this time.
Tee circuits are used in apartments or small private houses. The advantages include ease of installation and relatively low consumption of materials.
Collector wiring diagram. This method of formation water supply network consists in the fact that from the riser the supply pipe is led to the topographic center of the water supply system and ends with the installation of a comb.
The comb is a short pipe with threaded elbows installed on it for a ball valve. Thus, a distribution node is formed, from which distribution to points of consumption is carried out.
As a result, it is possible to shut off any water consumption point separately. The rest of the system continues to function as usual with the same water flow.
Operating temperature conditions
Manufacturers of products for water supply systems declare a maximum coolant temperature of 95 degrees. However, the physical properties of the material differ somewhat from this indicator.
Softening of polypropylene begins to appear at a temperature of about 140 degrees, melting occurs at 175. Taking these parameters into account, we can conclude that this material is suitable for any heating water pipes, with the exception of steam.
The operating temperature in the steam lines is exactly 175 degrees.
It would seem, what could be better? But the peculiarity of the material is that depending on the temperature in 135 degrees it starts to soften. The wiring begins to sag, thin out, and eventually a rupture occurs.
Manufacturers of polypropylene pipes officially declare a significantly lower permissible temperature, wanting to insure their products and make them more durable.
It should be noted that in a properly equipped home with sufficient thermal protection of the walls, this operating temperature is quite sufficient.
It should be noted that in heating systems it is advisable to use reinforced polypropylene pipes, which have a number of advantages:
- Stability of linear expansion of water supply elements under the influence of thermal and mechanical loads. They can withstand pressures of up to 10 atmospheres without noticeable changes.
- Service life of a reinforced pipeline constantly under pressure at elevated temperature is several times higher than that of non-reinforced products.
- The melting point in both products is the same, but under equal conditions, a pipe without reinforcement is destroyed, but a reinforced one is not.
How to solder polypropylene pipes with your own hands
The process of soldering polypropylene products is simple and therefore received wide use in the technology of installation of cold and hot water supply pipelines and heating systems.
However, there are some subtleties that you need to know and take into account in your work.
How to properly solder using the diffusion method - step by step instructions
The soldering process is based on melting the surface of a part to a certain depth. If in this state you connect two parts and cool them, the material returns to its original state and takes on its original structure.
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During this time, the melt has time to mix, creating a monolithic material to the depth of penetration. In physics this is called diffusion welding.
Making a joint involves performing the following technological operations:
- Use special scissors to cut the pipe to the required length.
- Bevel at a 45 degree angle on both ends.
- Clean the surfaces to be welded on the outside of the workpiece and on the inside of the fitting from any dirt and degrease.
- Install the required size nozzles on the soldering iron.
- Turn on the soldering iron and heat the mating parts for the time specified in the instructions.
- Remove the parts from the soldering iron and join them in the desired position. Hold until completely cooled.
Careful attention must be paid to maintaining the heating time. To obtain a high-quality connection, it is necessary that a solid base remains under the layer of molten plastic. This will allow the parts to fit coaxially. If the parts are overheated and the plastic softens throughout its entire thickness, it will be impossible to connect them, they will simply crumple.
From the table below you can see how much time is needed to successfully complete each stage of assembly. As you can see, the conditions are quite harsh.
When performing soldering yourself, it is important to assemble several test joints before starting work in order to feel the durability of temporary materials.
It is also necessary to pay attention to the accuracy of installation in the axial direction when mating parts. There will only be a few seconds left for control and correction.
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At what temperature to solder polypropylene pipes is established in the design of the welding machine; it is important to follow the recommendations for the heating time of the parts. This indicator depends on the power of the tool, which is different models may vary.
How to solder using the coupling (socket) method
This joining method is used to connect products to lengthen straight sections. A coupling fitting is used for this.
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It is installed on the end of the pipe by soldering, after which the second part is soldered. Soldering is carried out in accordance with the technology described above.
End soldering
It is more often called welding. The principle of operation remains the same - melting the material, compressing the two ends in a special mechanism, cooling. This joining method is used for products with a diameter of more than 63 millimeters.
End joining using this technology can be successfully used in field conditions. How to smoothly solder polypropylene pipes end-to-end?
To do this, it is necessary to carry out preliminary mechanical processing of the ends, ensuring absolute parallelism of the joined ends.
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How to properly solder reinforced polypropylene
Reinforcing layer, strengthening the structure of the polypropylene pipe. Creates a certain obstacle to the joining of individual parts. The reinforcing insert prevents the diffusion of the material, as a result of which the connection becomes unreliable.
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The only way to ensure a reliable connection is to remove the reinforced layer. Removal of the outer and reinforcing layer is carried out with a special tool - a shaver.
After cleaning the top layer, you need to carefully remove burrs and clean the surface of dirt, after which you can perform soldering using the above technology.
To understand at what temperature to solder reinforced polypropylene, you need to take into account that its structure is no different from ordinary pipes and the soldering modes are the same.
"Cold welding" in polypropylene joints
A two-component epoxy composition under this name has gained some popularity due to its effectiveness. The ease of use is attractive - just knead a lump of the composition and apply it to the surfaces to be glued. The hardening time of the mixture is about 10 minutes, complete setting is about an hour.
The physical properties of the adhesive composition do not allow its use on hot water supply or heating pipelines. It is only suitable for installing water pipes.
Connecting polypropylene pipes with electrical fittings
This installation method is widely used in industry. In this case, electrical fittings are used to make joints. A heating element is installed in the body of the part during its manufacturing process.
The system is installed without soldering, but each fitting is connected to the power supply. Only after wiring is completed is voltage applied to it.
Under the influence of current, the heating elements melt the mating parts to the required state, and shutdown occurs automatically. After the parts have cooled, the entire network or its local section is ready for operation.
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The use of this installation method significantly increases labor productivity and eliminates the personal factor when performing work. Therefore, the quality of connections is stable for the entire water supply network.
This technology allows for high-quality assembly of pipeline elements in hard-to-reach places.
Soldering pipes in difficult areas
When assembling a water supply or heating system with a complex configuration, problems may arise with access to the soldering area. How to solder polypropylene pipes in hard-to-reach places?
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During the preparation process, it is necessary to roughly break the entire network into separate nodes that can be connected on a workbench, after which the finished branches are welded into the system at two or three points. The following areas can be considered difficult to install:
- pipelines placed under the ceiling;
- in places where it is impossible to place a soldering iron.
The best way to avoid difficulties in this case is to prevent them from occurring. To do this, you need to think about the assembly order, making complex assemblies on a workbench, and not on your hands. If this is not possible, it is better to use electrical fittings.
In general, the occurrence of difficulties of this kind is a consequence of design errors. Manufacturability of installation is the main condition for the designer.
We install saddles in the water supply system
This pipeline element is used to create an additional outlet, and the need to install it usually arises when repairing existing distribution lines.
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A smaller fitting is soldered into a larger diameter pipe, allowing you to install a branch from the existing distribution at an angle of 90 degrees.
To do this you need:
- The craftsman needs to drill a hole of the required diameter in the wall of the existing pipe, remove burrs and make chamfers.
- The mating parts are heated with a soldering iron using traditional technology.
- The saddle (fitting) is tightly installed into the hole in the pipe.
This method of creating additional branches in the water supply system from polypropylene pipes makes it possible to continue the development of the network with the least amount of labor.
Knowing how to properly solder polypropylene will allow you to easily install pipelines of any length and degree of complexity.
Video on how to choose a machine for welding polypropylene
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Replacement modern systems heating and repair of water supply lines, the basis for which are plastic pipes, it is problematic to implement without the use of soldering. And therefore, the question of how to solder plastic pipes in order to connect them into a single system is relevant for many owners who decide to do the work themselves without involving craftsmen.
Selecting the necessary tools
Plastic pipes are an indispensable element both in construction and repair. They are easy to install, are chemically resistant and can withstand operating pressures of up to 2 bar at temperatures up to 95°C.
But it is impossible to perform high-quality installation of the system and correctly solder plastic pipes without using special equipment.
Due to the ease of installation and environmental friendliness of the material, plastic pipes are widely used in water supply and heating of residential buildings.
In addition to pipes and fittings of the required size, for welding work you will need:
- soldering iron with nozzles;
- building level;
- roulette;
- pipe cutting scissors;
- rags made of thick fabrics.
The soldering iron comes with attachments different diameters with non-stick Teflon coating. When heated, they melt the outer surface of the ends of the pipes and inner side connecting elements.
Advice: in order to save time on replacing nozzles during work, it is better to choose a device with the ability to install two or three heating sleeves at the same time.
For use in living conditions To solder plastic pipes with a diameter of 16-63 mm, a unit with a power of up to 1200 kW is quite suitable
When planning to solder plastic pipes yourself, you should adhere to a number of basic recommendations:
- The soldering iron is placed on the sole and secured with the legs on a flat surface. Nozzles of the required diameter are moved closer to the edge.
- They start working with the unit only after it has completely warmed up, which occurs 10 minutes after switching on. The readiness of the device will be indicated by the indicator light on the case.
- The parts to be connected are heated in parallel. Welding work can only be carried out if the temperature environment above 0°C.
- Remains of plastic from heated sleeves are removed immediately after each soldering stage, using pieces of thick fabric for this purpose. Cleaning cooled attachments is not permitted, as this may damage the Teflon coating and cause damage to the device.
You can avoid overheating by connecting plastic pipes with a soldering iron to the regulator
During operation, it is important not to exceed the heating temperature of the sleeve, the upper limit of which is 260°C. If the heating is insufficient, the plastic will not acquire viscous plasticity, which will cause an unreliable connection. And at an elevated temperature of 270°C, the material loses stability and sticks, preventing the pipe from fitting tightly into the fitting.
Tip: when working with a unit that does not have an electronic temperature control function that can control heating with an accuracy of one degree, you can use a special thermometer to measure it.
Plastic pipe soldering technology
Work on connecting plastic elements by soldering includes a number of main stages. Without experience in soldering plastic pipes, it is advisable to make two or three test connections in advance. To control the correct welding, it is advisable to cut the cooled sample along the axis, making sure that the joints are solid.
When preparing connecting elements, it should be taken into account that the inner diameter of the fitting should be slightly less than the outer diameter of the pipe combined with it
Preparing elements
Using a cutter or scissors, cut the pipes to the required length, maintaining the angle of inclination of the cuts within 35-45°. If it is necessary to solder metal-plastic pipes, the cut ends must be cleaned with a shaver.
Sections and working parts of the surface are degreased with a soap or alcohol solution. Markers are placed along the edges of the sections with a marker, which will act as a guide when joining the elements.
Performing soldering
Having heated the soldering iron with the nozzle to the required temperature, insert the end of the pipe onto the sleeve to the full welding depth, and thread the socket of the fitting onto the mandrel. The soldering operation occurs very quickly and lasts no more than 10 seconds. The countdown begins from the moment the ends are inserted.
The holding time and temperature at which plastic pipes are soldered are determined from the table
If you need to solder metal-plastic pipe with a connecting element, a fitting is first put on the heating sleeve, which takes more time to warm up the inner walls. A tight fit of the fitting on the sleeve is a prerequisite for high-quality heating.
When heating plastic elements, any rotation should be avoided. The maximum permissible rotation angle should not exceed 10°C.
Tip: for safety reasons, it is better to solder plastic pipes while wearing safety glasses and gloves.
Assembly of the structure
The melted ends of the heated elements are removed from the soldering iron and connected to each other, focusing on the marks marked with a marker. When connecting parts, no axial rotations to the full depth of the fitting socket are allowed under mechanical loads.
The process of how to solder plastic pipes is clearly presented in the video:
When plastic pipes are sealed correctly, a continuous bead is formed around the edge of the socket, which looks like a small ring.
Combining the details Special attention pay correct position taps and tees. When assembled, the faucet handle should easily rotate to any position.
The connected parts are left to cool completely, preventing them from turning. If the connecting seam turns out to be of poor quality, the knot is cut off and the operation is repeated.
Plastic water pipes and heating network They are popular in houses and apartments. Environmentally friendly, up to 50 years of impeccable service, a light weight and pleasant appearance- these are not all of their advantages. An important factor is the possibility self-installation, anyone can solder polypropylene pipes with their own hands.
PVC pipes are one of the most common materials in constructionNot required for work welding machine and specialized application knowledge. No, threading dies, vices and other devices. It will take a long time to learn. You can master the plumbing craft using PVC and learn how to professionally solder plastic in a few hours.
What equipment is required to create water supply and heating systems made of plastic
To solder, you don't need much additional equipment:
- A device for soldering plastic pipes, also known as a “soldering iron”, also known as an “iron”. Official name " ".
- Tape measure and marker. Plastic can only be soldered once; it is not suitable for reuse. Measurements must be accurate, unnecessary deflections must not be allowed, and when calculating, the distance at which the pipe enters the fitting must be taken into account.
- Alcohol, solvent or other degreasing liquid.
Theoretically, PVC pipe can be cut with a hacksaw, with a simple knife or a jigsaw. Soldering plastic water pipes requires care at all stages; an uneven cut can cause poor-quality welding, and small savings today will lead to large expenses tomorrow.
How a soldering iron works and how it works
Soldering is impossible without a special apparatus, which is a heating element with nozzles of various diameters, from 14 to 63 mm. The most expensive and high quality this moment soldering irons of Czech and German production. Soldering with such a unit can be done at a professional level. High price justified by long service life, reliability, and ease of use. Devices from China are much cheaper, the quality is lower, but do-it-yourself soldering of plastic pipes does not require frequent use, so we can fully recommend buying a Chinese product. The price starts at $20, which will pay for moving a couple of pipes in the bathroom.
The power of the device ranges from 650 W to 2 kW. In order to solder plastic at home, the optimal power consumption will be up to 1200 W; it makes no sense to use a high-power soldering iron when renovating an apartment or house. A welding machine is essentially the same iron, two heating elements of which simultaneously heat the outer part of the pipe and inner part fitting to operating temperature.
Soldering iron for PVC pipesWhen working with a soldering iron:
- Place the welding machine on a flat surface and attach the attachments to it. You can install several nozzles at the same time, while those that are necessary for installing pipes directly on the wall are placed on the edge. Install the nozzles before turning on the soldering iron. This is not a difficult matter, but on a hot surface there is a possibility of incorrect installation.
- Warm up for 5 to 15 minutes, plastic soldering occurs at a temperature of 260 0 C. A light indicator signals heating to operating temperature. Each soldering iron is equipped with a temperature regulator for greater convenience.
- Heating of the two parts being connected must be done simultaneously.
- It is recommended not to turn off the soldering iron during operation. This is due not only to the waiting time for the device to heat up, but also to the fact that plastic residues harden on the sleeves.
If you need to pause work, after turning off the power, while the soldering iron is still hot, you need to thoroughly wipe the nozzles with a rag. This must be done in compliance with all precautions when working with hot objects. Do not use a soldering iron with plastic residue on the tips. It is also strictly forbidden to clean cooled attachments. They are coated with Teflon, scratches on it will lead to failure of the device.
Installation of a water supply system using fittings
When starting to install a water supply system for the first time, it is advisable to practice and make several test connections.
Soldering plastic pipes with your own hands is not difficult, but it is a responsible task. So, by connecting a pipe with a fitting and cutting the connection, you can understand in practice how to carry out welding correctly. Professional work with polypropylene pipes consists of the following stages:
- Prepare the welding machine.
- Measure the required length of pipe and mark the cut location with a marker. Do not forget to take into account the depth to which it is inserted into the fitting.
- Use scissors to cut off the desired section.
- Clean the fitting and cut from dirt and dust, remove grease with a solvent, alcohol or other solution, and dry.
- Install the pipe into the sleeve up to the limiter. Install the fitting on the mandrel. Under no circumstances should you make rotational movements, this destroys the uniformity of the layer and makes the connection unreliable. Smooth input all the way is enough.
- Wait 6 to 25 seconds. The waiting time depends on the heater power and pipe diameter. The instructions contain a table for soldering polypropylene pipes, which gives the approximate waiting time for heating, fixing the connection and hardening. Much depends on the ambient temperature; the table gives the time based on the air temperature being 20 0 C. You can visually see that the plastic has frozen through a special hole in the sleeve. As soon as the plastic appears in it, it's time to move on to the next stage. Another sign of readiness will be the formation of an influx in the form of a roller.
- After heating, the parts are simultaneously removed from the soldering iron and connected to each other. Be sure to ensure alignment. And also no rotation, everything happens smoothly and without unnecessary effort. For pipes with a diameter of more than 40 mm, it is recommended to use special guides.
- Fix the connection for 5 – 10 seconds.
- It takes less than 10 minutes for the plastic to cool. The pipeline section is ready, you can proceed to the next one.
- At correct installation a roller of extruded PVC is formed on the outer surface.
To do it correctly, you need to avoid the following mistakes:
- alignment of parts after connection;
- the pipe and fitting are not joined all the way;
- excessive force when putting the pipe on the soldering iron and when connecting it to the fitting;
- insufficiently tight fitting of the pipe onto the heater sleeve or fitting onto the mandrel;
- repeated heating of the elements being connected, working with a soldering iron allows only one-time heating, then the plastic is deformed;
- overheating of parts is determined by the appearance of a brown tint of PVC.
It is easy to check whether the plastic has been soldered correctly with a soldering iron. By looking inside the connection or running your finger over it. There should be no significant internal sagging from excessive pressure or failure from insufficient joint density of parts.
Butt soldering of plastic
In cases where the plan provides for a pipeline with a diameter of more than 50 mm, butt soldering will be used. This connection method is more reliable, but it is only suitable for wall widths of 4 mm or more. To solder a plastic pipe end-to-end, you need the same tools and a device to maintain the alignment of the elements. The method is very similar to connecting with fittings, although there are a few differences:
- Soldering plastic pipes end-to-end requires rigid fixation of the axis; a special centering device is required.
- to solder the plastic, heat it with a disk attachment;
- The ends of the connection must be carefully aligned.
Marking of PVC pipes and their areas of application
PVC has found application not only in water supply, but also in heating systems. Each of them has its own options:
- PN 10. Thin-walled, for cold water supply, or systems where the temperature does not exceed 45 0 C. They are used in the “warm floor” system.
- PN 16. With walls of medium thickness, used in cold water supply systems with high pressure. or feeding systems hot water with low pressure.
- PN 20. Most universal option to create a water pipeline. Withstands high pressure and operating temperature up to 80 0
- PN 25. Standard for extreme conditions. Withstands high temperatures up to 95 0 C. To avoid deformation, it is reinforced with aluminum foil. Recommended for use in hot water supply and heating systems.
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The PN code is the pressure that the system can continuously withstand for 50 years, at a temperature of 20 0 C, measured in bar. At home, the rules for soldering with a soldering iron apply to all types PVC pipes. indicated by outer diameter and in the metric system. This is due to the fact that the dimensions of connecting parts and fittings are usually measured in millimeters. If you need to convert the metric system to inches, it is useful to remember that one inch is equal to 25 mm.
Self-soldering of plastic pipes for heating
In heating systems, only pipes of the PN 25 standard are used. Its peculiarity is that it is reinforced with fiberglass or aluminum foil, which avoids deformation from heating and high pressure. To properly solder a PN 25 pipe with a soldering iron, you need to remove the protective layer before work. In the event that it is located outside. If the reinforcing layer is located internally, plastic pipes must be soldered in the same way as when installing a water supply system. The protective layer is removed only in the area where the pipe enters the fitting.
With temperature changes, any material contracts and expands. If on small areas This can be neglected, then if the pipe is long, it is necessary to make compensators. It is a part of a pipe bent into a ring. It is located in an inconspicuous place and works like a coil of a spring, compensating for temperature deformation.
Polyethylene pipes, produced mainly from HDPE (low-density polyethylene), occupy a strong place in many areas of industry, construction and everyday life due to the presence of many technologically advantageous characteristics. This necessitates the need for optimal methods of connecting them, without which the process of installation and arrangement of pipeline lines is impossible.
Types of polyethylene (PE) pipe connections
Among the various types of connections between polyethylene pipes, there are detachable and permanent ones.
The detachable method allows you to disassemble the assembled structure at the end of use. Accordingly, it is optimal in cases where there is no need for its long-term use. This connection of pipes is carried out using steel flanges.
A permanent connection is more durable and more often used in practice. It is carried out by welding or soldering PE pipes, which, in turn, can be butt or coupling. Both methods are effective and reliable, allowing you to obtain monolithic, durable connections.
Butt welding of polyethylene pipes
For butt welding of polyethylene pipes, special welding equipment is required. This connection method is effective for soldering only HDPE pipes. Its versatility lies in the fact that it allows you to maintain the flexibility of the structure throughout its entire length. Be used this method can both during trench and open method pipe laying.
Butt welding of HDPE pipes is performed in the following sequence:
- Installation of the ends of the welded products in the centralizer of welding equipment.
- Alignment and tight fixation of parts.
- Cleaning the end sections from dirt, dust, grease, other debris and deposits (carried out using a cotton cloth soaked in alcohol).
- Processing of end fragments using a trimming device (trimming). The process is carried out until uniform chips appear, not exceeding 0.5 millimeters in thickness.
- Removing workpieces and checking the ends by hand for parallelism. If a significant gap is detected between the surfaces, repeat trimming until the required compliance is achieved.
- Heating the ends of the blank pipes with a heating element, the surface of which is covered with a non-stick layer.
- Upon reaching some melting of the workpieces, remove the heating element and close the ends of the pipes to be welded. The clamping pressure is increased until a complete and strong closure is achieved. The products should be kept for some time (usually 5-10 minutes) until the joint is completely hardened.
- Checking the quality of welded structures. The appearance of the welded ends, their consistency with each other and the soldering strength are assessed.
In addition to the welding process itself, it is important to pay attention increased attention preliminary work listed in the initial paragraphs. They should be carefully completed before soldering HDPE pipes, since the reliability and strength of the connection being made largely depends on this.
A prerequisite for high efficiency of butt welding is its implementation using a single seam. Only in this case is the maximum strength of the welded joint achieved, otherwise it may be insufficient.
Socket welding of HDPE pipes
The coupling method of soldering polyethylene pipes is carried out using a special device called a soldering iron and a set of special nozzles of the required diameter. During the welding process, fitting products are used: couplings, tees or angles. The ends of the workpieces to be joined are welded to fittings, which serve as connecting elements.
If you have the necessary soldering unit, you can solder HDPE pipes with your own hands. This work is not very difficult and can be done by any home craftsman.
Before you solder a HDPE pipe with your own hands, you should do some preliminary work, in particular:
- Trim the workpieces with special scissors until required sizes. The cuts must be strictly perpendicular to the longitudinal axis of the workpieces.
- Clean the end sections of the products to be joined.
- Close the ends of those pipes that are not currently being welded with plugs to avoid contamination and cooling.
- Clean the heated surfaces of the soldering unit from blockages and particles that may have remained from previous work.
- Heating the soldering iron attachment parts to the required temperature. When heating reaches the required values, the indicator on the device body gives a special signal.
- The HDPE pipe is inserted into the sleeve all the way, and the fitting is also pushed onto the mandrel all the way. This action may require some effort.
- As the pipe is inserted and the fitting is pushed onto it, excess molten material is squeezed out from the surface of the product. As a result, a kind of annular bead is formed in the area of the welded edge, called a burr.
- The parts to be connected are removed from the nozzle, after which the pipe is inserted into the fitting so that it is in tight contact with the annular roller. Read also: "".
- Wait until the welded pipes cool down without exposing them to any external influences.
Due to the fact that it is difficult to determine the exact immersion depth of the pipe during the welding process, you should measure it in advance and make a corresponding mark on the surface of the product.
Electrofusion welding
A special type of coupling welded joints of PE pipes is the electrofusion method, which makes it possible to obtain high-strength structures. To implement it, it is necessary to use a special electric coupling for HDPE, equipped with mortgages heating elements. The welding process is also carried out using welded HDPE fittings equipped with heating coils. Thanks to heating and partial melting of the fitting material, connection with the polymer pipe is achieved and the formation of a monolithic structure.
The elements and parts used in this method are quite expensive, however, the advantages of electrofusion welding are the absence of burr formation, which reduces the permeability of pipes, and the ability to weld parts in limited space where it is impossible to install large welding equipment.
Electrofusion welding between PE pipes is carried out in the following sequence:
- The pipes are cut into the required lengths using special cutting tools.
- The welded areas of the products and the electric coupling itself are cleaned of dust, dirt and grease.
- Marks are made on the pipes to control the depth of insertion into the coupling.
- Those ends of the pipes that are not currently being welded are plugged to avoid unwanted cooling.
- The electrofusion coupling is connected to the welding device via wires.
- The welding process is started using the device's start button.
- At the end of the welding process, the machine turns off automatically.
- Wait at least one hour for the welded joint to harden and become fully ready, after which it becomes suitable for use.
An important condition for obtaining a high-quality welded joint is maintaining the immobility of the parts during the soldering process and subsequent cooling. One of the indicators of the quality of the weld is the thickness of the bead, which should be from one third to half the thickness of the pipe itself. The roller should overlap the mark previously made on the pipe. The displacement of the welded pipe sections relative to each other should not exceed 10 percent of the thickness of their walls.
Choosing a method for soldering HDPE pipes
Not each of the listed options may be successfully suitable for connecting HDPE pipes in certain conditions. Various ways have their advantages and disadvantages, and along with this there are a number of factors on which the answer to the question of how to solder polyethylene pipes in a particular situation also depends.
The coupling method is optimal in cases where it is necessary to carry out soldering in hard-to-reach places. Since in such a situation the axial displacement of the products relative to each other is difficult, butt welding becomes impossible, and the only acceptable method is a sleeve connection.
In the most inaccessible areas with very limited space for work, HDPE pipes are soldered using the electrofusion method. Another significant advantage of this method is its speed, which is also sometimes important.
Finally, in cases where there is a need for a one-time connection of pipes to perform one or another short-term job, soldering is not required at all, and a temporary detachable connection can be used.
How to properly solder polypropylene (plastic) pipes
So, dear reader, you have decided to change the water pipes in your apartment with your own hands. And if your choice fell on polypropylene pipes, I will help you learn how to work with them correctly.
I won't go into too much detail technical description polypropylene pipes, a separate article will be written for this, and I’ll immediately move on to the instructions.
tool for soldering polypropylene pipes
From the tool we need:
- Alcohol marker (a marker for discs will do)
- Roulette
- Building level
- Special scissors for cutting pipes
- Soldering iron for polypropylene pipes
The last one on the list will be cheaper to rent; I don’t see the point in buying one for home, because... you will only need it once. You can rent it in the same place where you will buy plastic pipes.
This list is only necessary for soldering pipes. If you are going to lay pipes in a groove, it will be useful to read the article, in which I described the technology of wall grooves.
Instructions for using a soldering iron for polypropylene pipes
A soldering iron, also known as a welding machine for plastic pipes, has a base with heating elements inside and special holes for attaching nozzles for soldering pipes of different diameters. Attachments, as a rule, come complete with a soldering iron. The principle of operation of a soldering iron is almost the same as that of a home iron, except that in a home iron there is one heating element, and in a pipe soldering iron there are two of them and each has its own switch on the body of the soldering iron. In addition to the heater switches, there is also a thermostat on the body; we will use it to set the desired temperature.
Before turning on the heating element, you need to move the soldering iron from the traveling position to the combat position. Screw the stand to it and install the nozzles for soldering pipes in place. As a rule, the soldering iron base has two holes for nozzles; if you work with different pipe diameters, you can install two nozzles at once. Place the nozzle for smaller diameter pipes on the edge of the spout, as shown in the figure.
After this, you can plug the soldering iron into the network. Turn on both heating elements on the soldering iron body and set the temperature to 260⁰C. And be patient, the soldering iron should heat up for 10-30 minutes until the light on the case goes out. After this, wait another 5 minutes before soldering, so that the soldering nozzles heat up well.
How to connect plastic pipes
Heat the pipe and the fitting socket with a soldering iron at the same time. Below is a table showing the heating times for different pipe diameters.
Heating time for soldering polypropylene pipes
| Pipe outer diameter, mm | ||||||||||
| Distance to mark, mm | ||||||||||
| Heating time, s | ||||||||||
| Technological pause no more than s | ||||||||||
| Cooling time, min. |
