Is it possible to solder the HDPE pipe and polypropylene. We solder the HDPE pipes with a soldering iron for polypropylene. How to solder pipes: tools and technology. Heating element connection

Hello dear reader! If you need to lay a cold water pipeline, you can use low-pressure polyethylene (HDPE) products - an inexpensive and practical material. Each material has its own subtleties and installation features. In this article, we will tell readers how to connect a HDPE pipe.

Polyethylene is a widely used and well-known plastic. But they began to make pipes from it not too long ago - about 50 years ago. The name "LDPE" comes from the way the polyethylene is produced and is not related to the quality of the plastic.

Pipes can be black, bright blue, black with blue and yellow stripes, gray (for sewers), rarely other colors. For plumbing drinking water blue or black products with blue stripes are intended, black products are for technical purposes. Diameters - from 16 to 1600 mm. They are made as measured products with a length of 12 m or in coils (if the diameter does not exceed 160 mm)

Scope of application

HDPE are used exclusively for cold water pipelines, as they can be operated at temperatures not exceeding 40 ° C. Operating pressure– no more than 20 MPa (2 atmospheres). They are used everywhere for laying water and sewer networks underground and water supply systems from a well with a pump.

A wider distribution is hampered by instability to ultraviolet radiation - it will not work completely to switch to HDPE.

In addition, communication or power supply cables are laid in smooth or corrugated tubes.

Advantages and disadvantages of these pipes:

Advantages

low cost;
chemical inertness - does not react with either alkalis or acids; water does not acquire an extraneous taste or smell;
corrosion resistance; resistance to aggressive environments;
durability - the first pipes have worked for more than fifty years;
smooth inner surface - such pipes do not "overgrow" with calcium salts, like metal ones;
tolerate freezing with water inside and do not burst like metal ones;
not afraid of temperature changes (in the range from -20 ° C to 40 ° C):
plastic polyethylene easily tolerates soil movements;
manufacturability - easy and quick installation;
polyethylene is environmentally friendly - its production and disposal do not lead to environmental pollution;
light weight facilitates their installation, storage, transportation.

Flaws

the most significant drawback is sensitivity to ultraviolet radiation. Water pipes left in the open sun will begin to collapse in just a couple of years. That's why water pipes from HDPE are used exclusively in underground utilities and in rooms with artificial lighting or no light at all (for example, in basements and basement floors no windows)
not designed for hot environments.

Connection methods

Pipes made of low pressure polyethylene can be connected in detachable and one-piece ways. Below we describe each of these methods.

Plug connections

This type of connection is used on diameters up to 315 mm inclusive, but it is desirable to use on diameters not exceeding 110 mm. It is just as reliable as the one-piece methods.

Its advantages:

quick and easy installation;
cost-effectiveness - no special equipment is required; couplings and other fittings are not too expensive;
accessibility - can be used in cramped conditions, under water, for example.

Connectors (fittings, couplings) are mounted in the following order:

the ends are carefully cut perpendicular to the length of the pipe; cleaned of burrs;
chamfer is removed at the ends (using a special tool or a sharp knife);
a connecting element is mounted on the ends (it enters the adapter rather tightly);
then carefully tighten the nut on the fitting.

Coupling

This is the fastest and most equipment-free way to assemble pipelines. Can be easily applied at home.

Polyethylene couplings are of several types:

connecting - connect pipes of the same diameter;
reduction - used as a transition for different diameters;
compression - designed to connect PE pipes with various shut-off equipment, steel, propylene or PVC pipes.

Couplings are straight and angular. Types of couplings are shown in the table.

Fitting connection

Compression fittings are a type of connecting parts for water pipes.

Their installation is similar to the installation of couplings.

flange connection

Applies to main pipelines large diameter(not less than 40 mm) for the installation of gate valves, valves, regulators (for their subsequent removal for repair or replacement).

To fix the flanges, special couplings are welded to the ends of the pipeline, then the flanges are screwed onto them.

Permanent connections

Only possible method connections of large diameters.

Butt welding

Such welding is desirable to connect workpieces with a wall thickness of at least 5 mm.

The ends are cleaned, chamfered, inserted into a special heater, melted, then the workpieces are joined, pressed and held motionless until completely cooled.

Electrofusion welding

The two pipes to be connected are inserted into a special sleeve, inside which there is a heating element. Then voltage is applied to it from a special apparatus, the coupling and the workpieces are heated and welded. Highly convenient way welding. And very expensive. On large diameters, the cost of the coupling will far exceed the cost of the pipeline in your area.

When performing this type of welding, special attention should be paid to the preliminary cleaning of the ends and the immobility of the joint until it cools completely.

Requirements for welded joints

there can be no depression at the place of the seam - only a protruding roller;
the displacement of the ends relative to each other should not exceed 10% of the pipe wall thickness;
with a wall thickness of up to 5 mm, the thickness of the roller should not exceed 2.5 mm; for wall thickness - no more than 5 mm.

Step-by-step instructions for connecting HDPE pipes

Necessary tools and materials

centralizer;
hydraulic unit;
heater with temperature control;
electric trimmer;
inserts for various diameters of welded products.

Work progress

HDPE pipes are clamped in a centering fixture;
trimming and chamfering;
the ends are degreased;
surfaces are heated by a welding heater and melted;
the welding heater is removed;
the ends are compressed in such a way that a seam roller is formed;
the pipes are not touched until they are completely cooled, then the centralizer is removed.

Video by connection

It is always better to see the production process of any work. Our video will help you to see all the subtleties of the process of welding PVC pipes.

It is impossible to connect pipes with a pronounced ellipse - the quality of the seam will be unsatisfactory.

After welding in without fail the unit to be welded must be in a stationary state until it has completely cooled down.

Do not neglect cleaning the ends of the earth, dust, sand, chips and degreasing - these little things significantly affect the quality of the seam.

How to connect HDPE pipe with polypropylene

Polyethylene and polypropylene are not welded. Correctly connect them together only with the help of fittings. On the ends to be connected, one should weld or put on MRV (couplings with internal thread) of the appropriate material, screw a quick-release threaded connection (“American”) onto one MRV, then connect two MRVs using a union nut.

How to join a polyethylene and steel pipe

Such docking is carried out similarly to the joining of HDPE and polypropylene. Steel pipeline, as a rule, ends with a thread. You can use the drive instead of the “American woman” - but this option has already become obsolete.

Times change, technology changes too

For many years, the most common material used for organizing water supply and heating systems was steel products. However, such negative qualities as low corrosion resistance, ability to overgrow, high cost and complexity of installation, led to the need to find alternative materials for the manufacture of pipes. The creation of polymers opened new era in pipe production. In addition, do-it-yourself welding of polypropylene pipes is possible without special professional skills and bulky equipment. However, one should follow certain rules with PVC pipes, but more on that later.

Self-welding of polypropylene products

However, before going to a building supermarket or to the market, it is worthwhile to figure out what options a wide range of plastic pipes offers us today? To begin with, it is worth saying that all pipes made of polymers are called “plastic”, and they are divided as follows: products made of polyvinyl chloride (PVC), polypropylene, polyethylene, including cross-linked, metal-plastic.

Scopes of polypropylene materials, methods of their connection

Universal Solutions

One of the most popular and widespread are polypropylene pipes. They can be used for: cold and hot water supply, organization of the heating system, including "warm floor", sewerage, wastewater disposal.

For cold water supply

To supply cold water, you can use fairly cheap products labeled PN 16, which characterizes the value of the working pressure - 1.6 MPa. For hot water supply and heating - PN 20 with a nominal pressure of 2 MPa.
If you want to purchase products of a more modern range, then you can opt for structures reinforced with aluminum foil (do not confuse with metal-plastic ones!). A feature of working with such products is the need for their end cleaning before soldering. This procedure can be carried out either using special nozzles for a perforator, or using a manual shaver designed for four main sizes - 20, 25, 32, 40 mm.

Polypropylene materials, variety of choice

Multilayer and reinforced

Recently, among reinforced pipes, the most popular are multilayer pipes with a fiberglass layer in the middle of the wall section. If you purchase just such material, then trimming the ends is not required.

Do-it-yourself welding of polypropylene pipes is carried out using diffuser soldering, for which you will have to purchase or rent a special device. His choice will be discussed later. The welding process takes place at a temperature of 260 degrees, resulting in a very strong, completely homogeneous seam. The connection of blanks is carried out using tees, angles, couplings.

With metal parts - steel assemblies, taps, filters, mixers, counters - polypropylene pipes are connected using fittings with pressed into them brass inserts. In threaded connections, the sealing materials must not form a thick layer. It is optimal to use a fum tape or linen with paste. The torque when tightening such connections should be moderate to avoid the metal element falling out of the fitting.

Do-it-yourself polypropylene welding: equipment selection

Tool shape

Soldering irons for welding polypropylene products are divided according to the shape of the working body into rod and xiphoid (flat). Based on my own experience, I can say that it is more convenient to work with a soldering iron in cramped hard-to-reach places.

Soldering iron power

The power of the tool can be approximately selected based on a simple calculation. To do this, multiply the diameter of the pipe in mm that you are going to solder by 10. For example, to weld a product with a diameter of 50 mm, a power of 500 W is sufficient.

Quality and functionality

Quality soldering irons professional range have electronic adjustment, which allows to achieve good accuracy in setting the heating temperature. The sound signaling gives the chance of control of process in all three modes: heating, connection, fixing.

Nozzles for soldering irons

There are two types of soldering iron tips: Teflon and metallized Teflon. The latter has higher strength characteristics. However, if the Teflon nozzle is handled carefully - carefully put the tool in a case, wipe pipes and fittings with alcohol or other degreaser before welding - its service life will be quite long.

Manufacturers of equipment for welding plastic materials

Do-it-yourself welding of plastic pipes, of course, will be greatly facilitated when using high-quality ones. The most desirable, but also the most an expensive option are soldering irons of Czech production. Turkish and Russian models are much cheaper, somewhat lower in performance than Czech ones, but for home use they are quite an acceptable option. Often negative feedback received models that, when carefully checked, turned out to be Chinese fakes. One thing can be said about Chinese soldering irons - the cheapest ones are suitable only for short-term, rare use.

Advantages of using polyethylene pipes

Do-it-yourself welding of polyethylene pipes differs from similar work with polypropylene materials.

Polyethylene materials have a number of significant advantages:

first of all, it is flexibility, which makes it possible to lay nodes along a curved line without joints between straight segments;
light weight, the ability to fold during transportation;
the material is completely inert, does not interact with any substances in the ground;
does not emit toxic elements;
does not break in the cold.

PND polyethylene pipes can be used for water supply and sewer systems. Such parts do not wear out, do not corrode, do not overgrow, are not afraid of contact with aggressive substances and, most importantly, can change their length by 7% without losing performance. The throughput of this type of water supply is 30% higher than that of a metal counterpart with the same cross section, due to the ideal smoothness of the walls.

Electrofusion machines for welding HDPE pipes

Do-it-yourself welding of HDPE pipes is possible using an electrofusion joint. In such welding, special fittings are used, in which heating elements are mounted during manufacture. These can be elbows, saddles, tees and plugs. To connect products with embedded heaters, special electrofusion devices of the most varied degree of complexity and equipment are required.

If you want to use polyethylene pipes and not burden yourself with finding suitable equipment, then you can purchase PE pipes. They are intended for internal and external water supply, sewerage, drainage. Small diameters of such pipes (up to 63 mm) can be assembled using brass or polypropylene fittings with rubber rings for sealing.

If you decide to independently replace or mount a new water supply or heating system using plastic products, then this will be quite within your reach. But for the successful completion of the task, it is necessary to familiarize yourself with the basic principles of connecting the selected pipes and be sure to consult with professionals.

Plastic-based pipes are an excellent replacement for steel, concrete and others in the construction of sewer and gas pipelines. Soldering polyethylene pipes is used to obtain a high-quality one-piece transport system.

Usually soldering is carried out by butt or electrofusion method. Both technologies share a common physical principle. It is based on the action of interpenetration of molecules from two surfaces of PE or PVC products to be joined. However, there are some significant differences between the two technologies. In order to reveal more widely all the features of butt and electrofusion welding, we will consider them separately.

Butt brazing technology for polyethylene pipes

Butt soldering is most in demand during the installation of pressure pipelines, sewers and gas pipelines. In order for welded joints to meet strength characteristics, at the preliminary stage, the conditions for joining welded elements should be met:

pipes can be installed if they are made of the same material;
welded pipes must have smooth and clean end surfaces;
soldering is carried out with strict alignment of PE pipes using a centralizer.

Going directly to welding, it is necessary to take into account the temperature regime of the process. At this stage of installation work, the fact that polyethylene, PVC, and other similar plastics have a significant degree of linear and volume expansion when heated is taken into account. Rapid heating leads to an uneven temperature distribution with the formation large differences pressure at adjacent points in the joint zone, which can cause undesirable stress concentrations within the joint. Further technology for soldering PE pipes is reduced to the following operations:

With the help of a heating element, which is installed between the pipes to be welded, the ends begin to heat up, taking into account the specified temperature regime: HDPE pipes - up to 220 ° C, LDPE pipes - up to 200 ° C. The ends are brought to the heater manually. Then, using a hydraulic clamp, they are securely attached to the thermoelement under a pressure of 0.6-0.8 kgf/cm².
having withstood required time, the pipes are parted to the sides, the heater is removed, and the ends of the pipes are connected under a pressure of 1.0-2.0 kgf / cm², depending on the brand of polyethylene.
The last operation - cooling the seam, occurs naturally when the pressure is maintained for a certain time.
At the end of the technology, the strength of the welded joint, its size and bead configuration are controlled. After removing the pipe from the clamps, the seam is marked by assigning a serial number to it.

Throughout the process, it is constantly monitored by pressure and time. Change and reconciliation of these parameters occurs according to the cyclogram.

The electrofusion method is used when pipes have different wall thicknesses. Scope of application: low pressure pipelines(drainage, gravity sewerage), insertion into an already laid pipeline, repair and replacement of elements. The main difference between a coupling joint and a butt joint is a better soldering of pipes with a significant difference in their diameters.

Another advantage of such soldering is speed, ease of operation and the ability to carry out them in small areas. The principle of welding using electric couplings is to melt the ends of the pipes with an embedded metal spiral, and the technology of this process looks like this:

the ends of HDPE or LDPE pipes are cleaned of dirt and degreased;
an electric coupling is put on one of the ends of the pipe and clamped with a positioner;
after aligning the ends of the pipes, the coupling is shifted back so that the junction is exactly in its middle;
operating voltage is applied to the terminals of the electric coupling, the heating process is carried out automatically;
soldering is considered complete according to the indications of the fitting holes, from which molten polyethylene should appear;
cooling of the seam should take place without forced cooling in a state of complete immobility.

Plastic PE and PVC pipes are confidently replacing metal pipes in everyday life and industry. This happens due to the fact that they often surpass the latter in such characteristics as the chemical inertness of the material, relatively easy installation, ease of maintenance, slight local resistance in the line, and a long warranty period (up to 50 years). With regard to technology, it should be noted that the soldering of PE pipes involves a significant degree of culture installation work and good knowledge of the subject. This issue can be solved by training specialists on the basis of specialized educational institutions.

Welding HDPE pipes is a very simple process. It is carried out using specialized devices, they have a different look - depending on its type. The connection of HDPE pipes can be done in two ways:

joint to joint heating element with non-stick coating;
with an electrofusion coupler.

Each method has both its advantages and disadvantages.

Soldering HDPE in both ways can easily be done by hand. Connect in both cases should be butt to butt. This will achieve the appearance of the highest quality seam that can easily withstand the pressure declared by the manufacturer.

Heating element connection

The device that performs HDPE welding, using end melting, is rather cumbersome. The reason for this is not only the equipment itself, but also the centering element. After all, one of the most important do-it-yourself welding processes is the alignment of the ends. Since the quality of HDPE welding itself directly depends on this. The process itself is carried out in the following sequence:

special centering equipment securely fixes the ends for welding;
it follows with your hands, as carefully as possible, to remove a certain amount of material from the ends of the HDPE pipe;
after chamfering with a special device, it is removed;
checked by hand mutual arrangement ends, they should be directly opposite each other.

When all the preparatory work is completed, you can proceed directly to welding pipes. It is necessary to use the welding machine as carefully as possible, because they can easily get burned. Heating muffs also require careful handling. When the ends of the pipes have melted and become liquid, you can combine them. After that, the soldering should cool down for some time, after which it is checked.

Electrofusion welding

Soldering with a special coupling with embedded heating elements is a simpler and more convenient process. Its main advantage is that the welding machine is very compact. It is easy enough to use even in places where the quantity free space extremely limited. In this case, special fittings are often used to fix a new seam, if large-diameter engineering communications are being laid.

Soldering HDPE pipes with your own hands is quite simple. It includes several stages:

pipe end surface preparation ( clean off dirt and grease);
the coupling is put on the ends with the help of auxiliary tools (special reinforcement allows you to fix them as rigidly as possible);
after a certain amount of time, the clutch is removed.

When the seam has become strong enough, the fixing reinforcement is simply removed.

The main nuances of welding

When carrying out the installation process of polyethylene, many questions arise. In order to connect HDPE pipes correctly, it is very important to always remember some of the nuances:

when soldering is carried out on its own (auxiliary fittings are not used), it is important to correctly center the connected ends- for this you can use a hard and even surface (concrete, asphalt);
if special reinforcement is used, it is necessary to be as careful as possible, since pulling the material can damage it;
using connectors, it is important to keep track of time and temperature, since overheating of the material can prevent the production of a high-quality seam;
the connection of HDPE pipes must be carried out in compliance with safety regulations - the welding machine can severely burn your hands;
before using the welding machine, it is advisable to clean it in a cold state with a special cloth;
when soldering on your own, you must remember that you need to plug the holes at the ends with rags or special plugs, since the welding equipment can cool down under the influence of a strong draft (heating couplings are especially susceptible to this);
before each new use, the equipment must be checked, a test should be taken - this will avoid damage to the material.

Many are interested in how to connect HDPE pipes in such a way as to achieve the highest quality seam. This is very easy to do, you just need to use quality equipment and take into account all possible nuances arising in the course of work. It is also important to remember about the technology for implementing the process in question. The resulting connection must meet all the necessary standards.

The modern market for sanitary products pleases consumers with the opportunity to choose the most suitable option, but at the same time requires knowledge about the properties of materials and how to install them. The quality of the pipeline largely depends on the quality of the connection of individual elements, the most reliable, durable, hermetic of which is soldering.

Soldering copper pipes is not easy, you will need a special tool

Copper pipe soldering

Copper is an expensive metal, but a pipeline made of it has competitive advantages allowing copper systems to stay at peak demand. Properly made of copper will provide a long and trouble-free service life of plumbing throughout the life of the house, exceeding half a century. The practicality of processing such products lies in the simplicity of the soldering process - it is low-temperature, easily carried out at home with a gas burner or an electric soldering iron.

Set of tools

The complete set of tools, fixtures and materials used in the process for the soldering procedure is as follows:

tools for expanding, cutting and stripping pipes: expander, pipe cutter or grinder with the most thin disk, beveler, sanding paper, metal brush;
a tool for heating metal and melting solder: a gas burner or an electric soldering iron for 250 W;
materials with which the connection takes place: flux and solder from an alloy of tin with copper, antimony, silver or other additives;
auxiliary materials - napkins for removing excess flux, stands, gloves, measuring and marking tools.

Copper tubes will be connected without fittings - the edge of one is expanded with a pipe expander, another piece is inserted into it. The connection is heated, and the seam is poured with molten tin solder - a reliable hermetic joint is obtained that can withstand quite a lot of pressure and high temperatures. You can correctly solder copper pipes by understanding the principles of the ongoing process:

after cutting the tubes, before soldering them, the ends are carefully cleaned - all burrs are removed, and the edge is polished to bright yellow. This must be done to remove oxides from copper that prevent soldering;
after stripping, it is covered with a special composition - flux, which removes oxygen, preventing oxidation during welding, helps the molten solder penetrate deep into the joint;
flux-coated segments are put on one another and heated with a torch or soldering iron. The technology of soldering with a soldering iron in this case differs from working with a burner only in the absence of an open flame;
solder is brought to the heated surface under the flame - the tin is melted, drawn into the joint, spreading evenly around the circle of the joint;
after cooling, the excess tin will fall off by itself, and the seam will be hermetically sealed.

If you do not have special skills in such soldering, it is better to entrust it to professionals.

Advice. In everyday life, it becomes necessary to connect aluminum tubes, which are more difficult to process than copper. This will require aluminum solder and aluminum soldering equipment - a torch capable of heating the metal to 400 ° C. The specificity of the procedure is that the flux is not used, and the solder is not injected into the flame, but is applied to the joint: it melts from contact with hot metal.

Soldering pipes made of polypropylene PVC (plastic)

Polymer products are soldered at lower temperatures than metal. They are afraid of an open flame, so special electric soldering irons are used for welding, called welding machines.

Welding technology for products made of polypropylene (PP) is fundamentally different from working with copper. The connection of metal sections is the insertion of one segment into another, and then the sealing of the seam with the help of a weld from a softer metal. In the case of polypropylene, both segments melt, mix, completely penetrate one into the other, and when solidified, an inseparable homogeneous connection occurs. This type of welding is called diffuse welding. Latin word diffusio, meaning mixing. Soldering propylene pipes means doing three things:

melt the ends of the segments to a soft state;
connect one to the other without unnecessary turns;
wait for cooling - as a result, a homogeneous inseparable area is formed.

Soldering pipes for heating and plumbing at home

Due to the simplicity of the do-it-yourself procedure, it is carried out at home. To do this, you need to purchase:

electric welding machine for welding polypropylene;
attachments for the device (included with the device);
trimmer;
fitting;
accessories: marker, knife, tape measure.

Soldering polypropylene is much easier than copper

Do-it-yourself soldering of propylene pipes consists in sequentially performing the following operations:

Cut pipes to predetermined dimensions, prepare fittings if necessary.
Trim the ends - remove 1–1.5 mm of the protective layer from above. This can be done with a trimmer or by sanding with sandpaper.
Prepare the welding machine - equip it with nozzles according to the diameter of the pipes and plug it into the network. Polypropylene melts at 250°C. The device has a temperature relay and a heating indicator. When the desired temperature is reached, the device gives a sound or light signal that it is ready for the welding process.
Insert the pipe and fitting into the appropriate nozzles and hold the time strictly according to the instructions, avoiding either overheating or underheating.
Remove the heated parts from the nozzles, then solder by inserting one element into another. At this stage, the actions must be confident and clear - it is forbidden to move the elements back and forth or rotate along the axis.
Let the polypropylene cool down - leave the structure for a while without mechanical influences.
Check the connection visually for defects: if the technology is followed, the seam will turn out to be uniform and durable.

Proper soldering of large HDPE pipes at normal temperature

They are of two types:

low-strength - made under high pressure and acquire a low density;
high-strength (HDPE) - are made under low pressure, but acquire a high density.

Another name for high-strength polyethylene pipes - HDPE stands for low pressure polyethylene. The words "low pressure" in the name mean the conditions under which the products were manufactured and are not related to the scope. Low pressure polyethylene (HDPE) is used in conditions of high pressure and temperatures - in main gas or water pipelines. solder correctly polypropylene pipes is not an easy task.

Since HDPE products are produced in a wide variety of diameters (20 mm to 1 m 20 cm) and wall thicknesses, there is more than one method of their connection and many types of equipment for soldering polyethylene pipes. Welding of polyethylene pipes is carried out by one of the following methods:

butt (or butt);
socket;
electrofusion.

For such soldering, you will need a special soldering iron.

PE pipe butt welding industrial environment produced by an expensive and bulky unit with a mechanical or hydraulic drive. The set of the device includes guides for centering, a trimmer for even trimming of joined edges, a heating element, drives and timers. The butt technology itself is simple, but the equipment used is not cheap: the price of a welding machine for HDPE pipes averages 250 thousand rubles, and a separate heating element costs about 50 thousand.

The scheme of soldering polyethylene pipes with a soldering iron in hard-to-reach places

Soldering of polyethylene pipes occurs according to the following scheme:

the products to be joined are inserted into the machine for welding HDPE pipes, centered;
an automatic trimmer is inserted between them, which evenly cuts the HDPE, removing chips;
opposite ends are joined, visual control of the alignment and tightness of the edges is carried out;
the ends to be welded are degreased, a heating element is installed between them;
there is heating and melting of the ends at a given temperature for a certain time;
the heating element is removed and the connection cools down for the period set by the timer;
it turns out strong connection which does not affect the flexibility of the pipeline.

At home, it happens according to the same principle, but simpler devices are used - a soldering iron for polyethylene pipes. It costs from 30 thousand rubles, it is a Teflon-coated welding mirror and can withstand high temperatures - up to 300 ° C.

Butt welding parameters for polyethylene pipes: temperature, heating and cooling time - depend on the diameter and wall thickness, they are set by welders according to a special table. To eliminate errors in many devices, the settings are automatically configured.

Electrofusion welding of HDPE pipes belongs to the industrial category and consists in melting the section of the pipeline under the coupling, to which electric current is supplied, and the temperature rises. Electrofusion fittings for polyethylene pipes consume a large amount of electricity during operation and are considered more expensive, but they help out in cases where it is impossible to use a device with large dimensions. They can be used at home.

Soldering reinforced PVC pipes

You can solder using the same apparatus that is used for welding polypropylene analogues. The walls of PVC products are thicker and more rigid, so fittings are required to connect them. Their melting point is lower, so this type is not used for hot water supply - the walls of the pipeline are deformed under the influence of high temperatures. Soldering is carried out by an electric welding machine with nozzles on which the ends of the products to be joined are melted. To properly solder pvc pipes, you need to perform several actions:

clean the edges;
reinforcement, if any, removed;
set the melting point to no more than 200°C.

Tools, fixtures, sequence of actions are the same as when working with polypropylene samples.

WATCH VIDEO

Polypropylene, polyethylene or PVC pipes in everyday life are often referred to as plastic with one common word, and the principles of their connection have much in common. Not everyone knows how to solder pipes correctly, but everyone can learn.

How to solder pipes? In the article, we have to analyze the technology for connecting pipes and fittings made of copper, polypropylene, polyethylene and PVC. We are interested in both the technology of soldering connections and the necessary tools for this.

Copper

The exceptional reliability and durability of copper is well known. It is not subject to corrosion, does not overgrow with deposits and is not afraid of heating to high temperatures. Actually, it is enough to say that the oldest copper plumbing have been in use for over a century.

However: copper is a relatively soft metal.
Accidental mechanical damage to the water supply is quite possible.

In countless videos posted on the Internet, soldering copper pipes is shown and described in sufficient detail. Let's pay attention to those moments that are often left behind the scenes.

Tools

To connect pipes by soldering, we need:

pipe cutter. A simple tool to help you cut copper tube strictly at right angles to its axis, thereby ensuring maximum reliability of the connection.
beveler. With it, burrs are removed from the inner and outer edges of the pipe.
Pipe Expander. It helps form the solder sleeve. Of course, this tool is needed only where it is not used.

Attention: the formation of a sleeve is only possible on annealed copper.
Without annealing, the metal is not ductile enough.

Burner. It can use propane or acetylene. AT living conditions the most convenient burners designed for use with disposable cylinders of small volume.

In addition, flux and solder are needed. At home, it is optimal to use the so-called soft solders tin based.

Technology

The surfaces to be soldered are cleaned of dust and, if necessary, degreased with acetone.
A sleeve is formed using a pipe expander. The diameter of the gap between the inner surface of the sleeve and outer surface the next pipe should be minimal - no more than 0.125 mm. The length of the sleeve is not less than the diameter of the tube.
A small amount of liquid flux is applied to the surface with a brush.
The sections of the water pipe combined with each other are evenly heated by the burner. When in contact with copper, the solder should melt.
With continuous heating of the joint, the solder bar is melted at the neck of the sleeve. The melt fills the cavity due to the capillary effect.

Polypropylene

How to solder propylene pipes? Of course, in this case, it is not difficult to find an appropriate video on the net - soldering propylene pipes is not too complicated and therefore is in great demand. Let's focus on the subtleties and nuances of this work.

Tools

The apparatus for soldering pipes is a low-temperature soldering iron with interchangeable nozzles for different diameters.

Useful: most of the cheap soldering irons are devoid of a temperature controller and heat the nozzles up to about 260 degrees.
It is at this temperature that PP pipes are soldered.
The regulator is necessary when it is necessary to set a lower value for working with polyethylene.

The presence of a pipe cutter is also desirable here. Outwardly, a pipe cutter for plastic pipes most of all resembles a garden pruner.
In addition, soldering PP pipes with aluminum reinforcement requires a shaver (stripping) or trimmer. The choice of one or another tool depends on the location of the reinforcing layer.

Technology

How the actual soldering of propylene pipes is performed - the video in the training courses shows more than clearly.

An appropriate nozzle is installed on the heating element of the soldering iron. corresponding to the pipe diameter.
The soldering iron is heated up to operating temperature.
Then two operations are performed simultaneously: the pipe is inserted into the socket of the nozzle and at the same time the fitting is put on its narrow part.
After 6-10 seconds (the exact time depends on the diameter), the parts are aligned with each other and held motionless for 10-15 seconds.

As always, the devil is in the details.

Pipes with an outer layer of reinforcing aluminum foil cleaned with a few turns of the shaver - nozzles with knives inside. Shavers are produced both for manual cleaning and for a drill chuck.
If the reinforcement layer is located between two layers of polypropylene, the preparation of the pipe is performed by a trimmer. The knives in it select a part of the pipe material from its end.

Explanation: stripping is needed so that all layers of the pipe are securely welded to the fitting, and aluminum does not come into contact with water.
Its electrochemical decomposition can lead to delamination of the water pipe section.

combined in a reciprocating motion. Rotation is unacceptable: the resulting wave will weaken the connection.

It is desirable to remove the outer chamfer on the cut pipe before soldering.

Polyethylene

Soldering of polyethylene pipes is carried out in two ways:

Using electrofusion fittings. Inside each fitting is a high resistance conductor. Applying 12 volts to the contact terminals leads to its heating and reliable connection of the fitting with the pipe inserted into it.

End-to-end, with preliminary melting of the ends of the parts to be combined.

The first connection method does not hold any surprises: soldering HDPE pipes (made of low-pressure polyethylene) is reduced only to assembling the water supply and short-term connections of the transformer to the terminals. Let's focus on butt soldering.

Tools

It is worth mentioning one subtlety. Normally, the butt-soldering technology for HDPE pipes is used for large (from 50 millimeters) diameters and uses rather sophisticated equipment for centering and clamping. However, the method can also be used for welding pipes in country water supply systems, irrigation systems and other pressure systems with moderate pressure.

Actually, the toolkit differs little from what is needed to connect polypropylene pipes.

Soldering iron. It is better to use temperature-controlled devices: soldering polyethylene pipes requires heating not up to 260, but only up to 220 C.
Pipe cutter. The ends must be strictly perpendicular to the axis of the pipe.

Technology

Actually, the soldering of HDPE pipes is even simpler than in the case of polypropylene.

The ends are tightly pressed against both sides of the heating element of the soldering iron and held until a burr appears - a roller from the plastic melt.
Then they are combined and held for a minute in a static position.

Attention: it is better to use a soldering iron with a Teflon-coated heating element.
Otherwise, part of the plastic will remain on its surface and, believe me, the air will not ozonize.

PVC

What does soldering PVC pipes look like?

State - no way. Generally. Both pressure and non-pressure water pipes and elements of sewer systems are connected only by sockets, using glue or rubber seals.

On the picture - pressure pipes from polyvinyl chloride. The tightness of the connections is ensured by rubber seals.

However, in some cases, soldering PVC pipes in free-flow sewers is still practiced. Typical situations are a breakdown of the siphon elbow in the late evening or the need to make a fitting of a non-standard configuration.

Like any thermoplastic, PVC can be melted and bonded relatively securely by molecular diffusion. It is clear that buying a special soldering iron will be some overkill.

How to manage improvised means?

The blanks are cut to size with a hacksaw or, which is much more convenient, with a grinder with any cutting wheel.
The edges of the mating parts are slightly melted over the stove or in the flame gas burner and hug each other.
Then the seam is melted in a circle with a table knife or any other metal object heated to a dull glow.

Often there are cases when, when manufacturing a pipeline, one has to face the problem of connecting pipes from different materials. In this article, we will look at how to connect a HDPE pipe to a polypropylene pipe.

Types of connection of a polypropylene pipe

To connect a polypropylene pipe with other types of pipes, there are special threaded fittings. One side of the fitting is welded to a polypropylene pipe, and the second side, with a thread, is connected to a thread of the same diameter on another pipe. The thread on the fitting can be internal or external. Also there are combined couplings. We will consider them later.

Another type of polypropylene pipe connection is based on a flange connection. This type of connection is used in pipes big size. For mounting flange on poly propylene pipe a sleeve is welded, on which a flange is then put on. Another mounting option is carried out with cap flanges. Their device resembles a compression clutch. The flange connection is attached to the edges of the pipe of the same diameter, and tightened with union nuts.

Types of connection HDPE pipes

The HDPE pipe has approximately the same connection devices. The most common is a push-in connection. To connect pipes, a coupling is used, in which there is a collet on one side and a thread on the other. To fasten the coupling, the clamping nut is unscrewed and put on the HDPE pipe. The collet is inserted into the pipe, the clamping nut is put on and tightly tightened.

Note! The clamping nut must not be clamped very hard, otherwise it may burst or the collet will crush the edge of the pipe.

After connecting the collet to the other end of the threaded coupling, you can wind another pipe with a thread of the same diameter.

Flange connection of HDPE pipes is carried out similarly to the connection described above. A sleeve is welded to the edge of the HDPE pipe, onto which the flange is attached. And the same device with a union flange, where the connection is installed on the edges of the pipes and pressed with union nuts.

Connection of two pipes

Using the pipe fittings discussed above, you can easily connect a HDPE pipe to a polypropylene pipe.

In the first case, you attach a threaded collet to the HDPE pipe, and a combined threaded coupling to the propylene pipe. Wrap the FUM tape for sealing on the thread and twist them.
In the second case, you connect two pipes with flanges. Insert a rubber gasket between the flanges for sealing and tighten them with bolts.

Combined couplings

If everything is clear with a collet connection for HDPE pipes, then combined couplings (fittings) for polypropylene pipes are diverse. Let's take a look at them briefly:

A coupling with an internal thread is used to connect a pipeline to another type of pipe or devices that have an external thread. It consists of a polypropylene blank with a metal sleeve pressed inside, on which a thread is cut inside.
The coupling with an external thread performs the same functions as discussed above. It differs only in that a metal sleeve with an external thread is pressed into the polypropylene blank.
A socket with a turnkey internal thread consists of a polypropylene blank, into which a metal sleeve is pressed, protruding beyond the edge of the polypropylene with metal edges. The edges are designed for open-end wrench. A thread is cut inside the face. It is convenient to wind such a sleeve with a key on another thread. There are also models of couplings with turnkey faces.
A socket with an external turnkey thread is the same as the socket described in point 3, only it has an external thread.
The split coupling with an internal thread consists of two metal parts for an open-end wrench. Moreover, one metal part is connected to a polypropylene blank. Such couplings are installed in places where it is necessary to disconnect the pipeline or remove devices. Another name for this clutch is American. It spins with two keys.
A split coupling with an external thread is similar to the previous type of American. The only difference is external thread instead of internal.
The coupling with union nut consists of a polypropylene blank into which a fitting with a turnkey union nut is pressed. It is installed in the same way as the American: in the places of the required pipeline connector.

With such combined couplings, soldered to a polypropylene pipe, it is easy to connect to a HDPE pipe, which has a collet with a similar thread.

Soldering PP fittings

Before connecting two pipes with fittings, they must be fixed to the pipe. We discussed the fastening of the collet on the HDPE pipe above. Now consider the connection of a polypropylene pipe with a fitting.

Polypropylene fittings with a pipe are connected by soldering with a special soldering iron. The soldering iron with nozzles is installed on a stand and heated to 260 ° C. The edge of the pipe is cleaned of dirt, chamfered and degreased along with inside couplings. The pipe and fitting are simultaneously put on heated nozzles. After heating, the pipe is inserted into the fitting exactly without turning and allowed to cool. This completes the soldering process.

After reading this article, you can easily connect a polypropylene pipe to a HDPE pipe. Here are all possible options correct connection. There are enthusiasts who claim on construction forums that these two pipes can be soldered with a coupling at different temperatures. But the thing is that polypropylene and HDPE consist of different materials, they have different melting points, so such a seam can burst or even melt. If you decide to save money and experiment, then do it at your own peril and risk.

Video

One example of how to replace a section of an iron pipe with a polypropylene one. By the same principle, you can connect plastic pipes from various materials:

Currently, more expensive and heavy pipes made of metals and alloys are being replaced by products made of various kinds polymers - polypropylene, polyethylene, etc. Such pipes, although they cannot completely replace metal ones, are actively used in almost all areas of industry and in urban communications. Products made of low-pressure polyethylene (HDPE) are especially popular; below we will talk about its application and how to connect HDPE pipes to each other and to products made from other materials.

Areas of application for low-density polyethylene pipes

Due to the lightness, strength and variety of ways to connect HDPE pipes, they are used in many areas, for example:

arrangement of water supply systems;
installation of sewer circuits;
as protective boxes power cables and wires when creating electrical networks;
as water-repellent shells when laying heating mains;
to prevent damage to cables of communication systems;
when digging artesian wells;
as molds for casting;
for supplying water to vegetable gardens, greenhouses, etc.

Methods for connecting HDPE pipes

If possible, both connect HDPE pipes and disconnect them back, fastening methods are divided into:

detachable- additional parts (reinforcement) are used to fix the elements; the design can be repeatedly assembled and disassembled, replace individual components;
one-piece- welding, gluing, etc. are used to fasten the elements; it is impossible to disassemble the finished circuit without damaging the components.

Advantages of the first method:

economy- Detachable connection allows you not to buy unnecessary parts, if necessary, replace only one; in addition, there is no need to purchase specific devices for welding or soldering pipes;
ease of operation- connecting HDPE pipes with fittings is quite easy to implement and does not require excessive physical effort; in addition, it is possible in conditions that do not allow the use of welding machines, for example, in the liquid column;
rapidity– with the necessary skill and quality of consumables and fittings, the work can be completed in a short time

Making a detachable pipe connection

This type of fastening of parts can be done in two ways:

in the bell. In this case, the narrower end of one pipe is inserted into the expansion - the socket - of the other and sealed with special materials. In most cases, it is used in the design of non-pressure (gravity) sewerage.
Fitting and flange connection of HDPE pipes - as the name implies, to ensure this method of fixation, special devices: flanges, couplings for HDPE pipes and others.

Couplings for plastic pipes

Like the products themselves, the couplings for HDPE pipes are made of polyethylene. When producing products, an extrusion technique is used.

Advantages of using couplings:

durability - the product can serve for decades;
reliability of pipe fixation and tightness;
resistance to temperature changes and external mechanical loads;
chemical neutrality;
versatility of use;
the ability to both connect a HDPE pipe with polypropylene, and fasten pipes from one type of plastic.

Types of couplings:

Compression. Both external and internal threads are applied to it. The fitting is usually used in the arrangement of heating and gas supply circuits. It is this type of coupling that solves the question of how to connect a HDPE pipe to a metal one: for this, a metal thread is applied at one end of the product. See also: "".
Simple coupling . Used to connect similar plastic products having the same cross section.
reduction. It is used in cases where it is required to fasten pipes of different diameters. As you might guess, the input diameters of such a coupling are also different.

Compression connectors

How to work with compression fittings:

The product is disassembled by loosening the union nut.
The surface of the pipe section is cleaned of dust, dirt, grease, etc.
At the end of the pipes, chamfers are made using special device– a beveler – or a simple sharp knife. The second method is less accurate and poses a certain danger to the health of the worker.
On the surface of the pipe, mark with a marker how far it will go inside the fitting.
Before entering, the end of the pipe is treated with liquid soap for better sliding.
The pipe (with force) is inserted into the fitting, carefully, avoiding damage, overcoming the resistance of the rubber seal.
Check the accuracy of the connection and tighten the union nut without applying excessive force to avoid damage to the fitting. See also: "".

Permanent connection of polymer pipes

Types of pipe welding:

butt;
using electrical couplings.

When using the first method, a pipe welding machine is required that heats their ends to a melting temperature. After that, the ends of the products are pressed against each other until cooling and the formation of a homogeneous mass.

pipes must be round, without deformation;
the seam must pass through the entire thickness of the wall of the product;
elements must not be displaced by more than 1/10 of the wall thickness;
the height of the welding bead for products with a wall thickness of not more than 5 mm - 2.5 mm or less, for thick-walled pipes (6-20 mm) - more than 5 mm.

When welding with an electric coupling, special polyethylene couplings with built-in electric spirals are put on the ends of the pipes. After voltage is applied, the ends of the pipes are heated, melted and welded to the coupling. Before carrying out the operation, the surface of the pipes must be cleaned, and during heating and cooling, the products must not be displaced relative to their original position.

The connection of HDPE pipes has many variations, it is quite simple in execution and, with the proper quality of work, is durable and reliable.

In modern construction, polyethylene pipes are used very actively. With their help, non-pressure and pressure pipelines are created - these are sewer networks and water supply systems, irrigation systems, and the like. The connection of HDPE pipes with fittings allows you to carry out all the work with minimal labor.

For water and sewer networks, low-pressure polyethylene is used, grades PE-100 and 80.

Polyethylene is characterized by elasticity and strength, as well as ease of installation - all work will be carried out at minimal cost.

Advantages that allow the use of HDPE pipeline in networks various types, are:

long operational period - up to 50 years;
immunity to external aggressive environments;
the possibility of creating a pipeline without digging trenches, which significantly reduces the cost of the system;
lack of tendency to corrosion;
pipes are smooth inside and do not become clogged with deposits during operation - high throughput stored regardless of the period of use;
light weight greatly facilitates installation;
ease of processing and creating connections allow you to create the most complex network configurations;
resistance to temperature fluctuations;
increased plasticity, mechanical strength- such pipelines are immune to ground movements, and therefore can be used even in regions with seismic activity.

The only limitation for such pipes is the temperature of the transported medium. It should not exceed +40°С (at +80°С polyethylene becomes soft). So for mounting heating systems other pipe types should be selected.

How are polyethylene pipes connected?

Do-it-yourself HDPE pipe connection can be done using 2 technologies and depends on the purpose of the pipeline:

Features of a detachable connection

The detachable connection can be dismantled without violating the integrity of the pipe itself. The connection of HDPE pipes with compression fittings is most often used during the installation of various water networks. The principle of joining two pipes is that the internal elements of the fitting are crimped, creating a reliable tight connection.

The compression fitting includes the following structural elements:

outer threaded body;
ribbed, easy-to-tighten union nut, which is screwed onto the body;
sealing rubber ring, with good wear resistance;
a sleeve for pressing in, which allows you to securely fix the rubber seal;
clamping ring, made of a material that is more durable than low-pressure polyethylene - polyoxymethylin;

To carry out pipeline assembly work, an open-end wrench may be required to fix the fittings (in practice, fixing is almost always done manually) and a knife for cleaning the surface of the pipes.

The technology itself, how to connect HDPE pipes with fittings, is as follows:

The upper protective layer on the pipe is removed by special stripping, or the pipe section is simply cleaned from contamination, which makes it possible to guarantee best connection. The length of the leg must match the size of the fitting. A chamfer is removed at the end.
The union nut on the fitting is untwisted, after which pipes are installed in it.
When the union nut is installed back on the connection, the pipe will be clamped by the ferrule (this process is called compression). When fixing the ring, it is very important to control the force, otherwise the body will burst from excessive pressure.

Detachable connection of HDPE pipes without welding using fittings

It is advisable to use compression fittings in pipelines with a small diameter, where the dimensions of the pipe do not exceed 63 mm (although it should be noted that maximum diameter such fittings - 110 mm). If the connection suddenly has to be disassembled for repair, then the fitting can be reused. However, before this, the integrity of the clamping ring should be checked - if necessary, it can be replaced.

If it becomes necessary to join HDPE pipes and polypropylene products, fittings can also be used. Welding in this case is impractical, since the materials have different characteristics. The connection here can be made with threaded or compression fittings.

How to connect HDPE pipes to metal - flange connections

The connection of HDPE pipes with metal is carried out using flanges. This method is best used when low-density polyethylene pipes should be connected to an existing cast iron or steel main. Structurally, the flange is a steel product with a connector for installing a HDPE pipe. These can be welded bushings or cap elements, which are best used for those pipelines where it may be required quick dismantling(for repair, cleaning, elimination of accidents).

Two mounting methods can be used − locking connection or threaded flange. With the fixed connection method, the flange is mounted on a metal pipe, after which the HDPE pipe is placed in it, and then the entire structure is fixed thanks to the clamping ring. The clamping ring is provided with a rubber seal, which provides better sealing of the connection.

The threaded flange is a threaded pipe. There is also an additional seal for tightness. It is advisable to use a flange connection when installing pipes of large diameters, as well as when connecting polyethylene pipes to steel valves and pumps.

Important: During installation, the steel flanges must be free of burrs or protrusions that could damage the pipe.

Such connection methods are classified as detachable. It is advisable to use them when welding is not economically justified or is impossible due to technical features installation of a specific pipeline. Detachable connections are characterized by low cost, because specific devices or professional equipment are not needed here. In addition, the creation of detachable connections is possible even in a limited space, and depending on the tasks, you can choose one of the methods - connecting polyethylene pipes with fittings or flanges.

Connecting HDPE pipes with fittings video

And here is a video on the topic of our article, which shows the connection of polyethylene pipes with compression fittings.

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