Connection of metal-plastic pipes. Connecting metal-plastic pipes - assembling a reliable pipeline Joining metal-plastic pipes

To save money when installing pipelines, the metal connection plastic pipes must be carried out in accordance with mandatory rules. Despite the fact that the price of components for this type of pipe is significantly higher than for polypropylene analogues, metal and plastic pipes today continue to be widely used in the construction of water pipelines and.

Metal-plastic pipes combine the advantages of two materials:

the metal in the composition of such a product provides it with strength;
plastic provides flexibility to the product.

So how to connect metal-plastic pipes Can different ways, then you need to understand the features of each, and our article will help with this.

Connecting metal-plastic pipes to each other

Connection using compression parts

Basic rules (the work is not difficult, so you can do it yourself):

With this connection method, it is assumed to use special crimp fittings (connectors for metal-plastic pipes) made of brass. The part, which in this case is used to connect pipes, is a prefabricated structure - a union nut, a fitting and a split ring.
A wrench is required to get the job done.
The compression fitting can be disassembled if necessary and then reused.

Operating procedure:

prepare a pipe of the required length;
align the workpiece section at a distance of 10 cm before and after the cut line,
cut the pipe according to the markings using precision scissors, which are positioned at right angles to the axis of the pipe;
check the integrity of parts and gaskets;
put on the nut and then the fitting ring;
process the end of the pipe with a reamer - the internal chamfer is removed with the calibration side, and the external chamfer - with the other side;
use fittings for connection (the pipe must be pushed onto the fitting until it stops);
screw the union nut onto the fitting by hand and then with a wrench so that 1-1.5 turns of thread remain free.

When tightening the nut, you must be very careful so that the ring does not burst.

Connection using special press fittings

There are ways to connect metal-plastic pipes that allow for high-quality installation of a heated floor system, as well as hidden communications. One of them is to ensure the connection of metal-plastic pipes using press fittings. This connection is more reliable compared to the option when compression parts are used. To perform the work you will need a special tool -.

To know how to properly connect metal-plastic pipes, you need to clearly understand the entire process of making the connection:

it is necessary to calibrate the cut edge of the pipe - remove the outer and inner chamfers;
check the pipe diameter with a calibrator;

check the presence of O-rings in the fitting, as well as the presence of a dielectric gasket;
place a crimp coupling on the edge of the pipe;
put o-rings on the fitting and insert it into the pipe;

crimp the steel coupling using press pliers (this tool should include liners for pipes of different diameters). When crimping a steel coupling, you must ensure that the side of the sleeve is in the recess of the press nozzle.

When making a press connection of metal-plastic pipes, it is not advisable to press the steel coupling twice.

If the press fitting has a coupling attached to it, then it is immediately placed on the pipe, and through the hole in the coupling, control the depth of its seating.

Connection using push-on fittings

With this method of connecting pipes, you will need, in addition to press pliers, an expander to expand the diameter of the pipe. The result is a permanent connection. It can be used when hidden installation pipelines, including when pouring concrete.

When carrying out work it is necessary:

cut the pipe;
place a coupling on the edge of the pipe;
expand the edge of the pipe using an expander;
place the fitting on the edge of the pipe;
clamp the coupling with a press;
the fitting is tightened onto the fitting, ensuring a reliable tight connection.

Application of a hybrid connection of metal and metal-plastic pipes

How are metal-plastic pipes connected to a metal riser? In this case, a hybrid connection is used.

For this job you will need a gauge as well as a compression fitting. If the products have different diameters, you should select a thread that matches the diameter of the metal pipe, and the washer with nut, collar and cone must match the metal-plastic pipe.

The work is carried out in this order:

you need to wrap tow on a metal pipe;
screw the fitting onto it;
Place a washer and nut on the metal-plastic pipe;
calibrate the edge of the pipe, put it on a cone screwed to a metal pipe;
Using an open-end wrench, carefully tighten the nut (the washer tightly squeezes the metal-plastic pipe).

You can and should make high-quality connections of metal-plastic pipes yourself. However, all work should be carried out in such a way that the connection technology is carried out accurately. Wherein Special attention will need to be given and .

Many people have a preconceived idea that the connections of metal-plastic pipes, as well as PERT and PEX pipes, with fittings are unreliable and leak. Let’s figure out where this “fame” came from and why it doesn’t correspond to reality.

How to properly connect metal-plastic and other similar pipes, and make heating and water supply pipelines from them?

Several types of metal-plastic pipe connections

Several types of fittings are used (crosses, angles, couplings...) to connect metal-plastic pipes.

Push fitting connection

Here the pipe is put on a fitting with a seal, and is crimped with a ring with antennae (a disc washer). There is an obvious click. The antennae of the ring are located opposite the direction of separation and prevent the pipe from moving back.

Push appeared relatively recently, and according to some experts, it appeared “for the sake of extorting money through advertising, since it has no usefulness.”

Indeed, manufacturers do not give the go-ahead to embed this connection in concrete. The resulting connection looks “flimsy”; the pipe rotates in the fitting, and with great force it can be undone back.

Combined with the fact that the price of such a fitting is 2 times more than the usual compression or crimp fitting, it is difficult for this connection to gain popularity without advertising.

The main difficulty of connecting with any type of fitting is preparing the metal-plastic pipe - determining its length, marking, cutting to size, shaping the cut edge, aligning the end part, chamfering, calibrating.

And not at all in the docking process itself. If you know all this, then Push-docking appears even more as the last thing needed in the household.

How should a pipe be prepared for joining?

To connect to any type of fitting, the metal-plastic pipe must be prepared.
To do this, you need to have a couple of special tools - pipe cutting scissors and a calibrator with an internal chamfering function.]

The pipe is supplied in coils. After cutting with a metal hacksaw, you get a piece of curved pipe, including one bent at the end, with a crumpled semi-oval end, with burrs along the edge and with sharp edges. Such a pipe will damage the seal on any fitting if you try to push it onto the fitting.

Needs to be cut with scissors. If this expensive tool is not available, then after using the hacksaw, you need to carefully align the end with a file and remove burrs.

It is necessary to manually align the final section of the pipe, no less than 5 diameters long.
The outlet hole must be forcefully calibrated (made exactly round) and at the same time the internal chamfer must be removed at an angle of 45 degrees.

Only after this can you begin docking.
Reducing the labor intensity of docking with Push does not have a priority value compared to its disadvantages...

Press fitting connection

The most reliable, non-separable connection of metal-plastic pipes is using a press joint.
Here the pipe slides onto a brass fitting with a pair of seals located in deep grooves.

The pipe around the fitting is crimped with a special metal sleeve, which is crushed and crimped only with a special tool - press pliers. The pipe should be pushed all the way and visible in the sleeve window.

This connection, according to manufacturers, has a reliability close to 99.99%. The connection is recommended by manufacturers of press fittings for use inside structures, including in walls and in screeds (but in heated floor loops, any joints are unacceptable).

No leaks have been recorded, except in cases where obviously counterfeit parts were used.

Connecting a metal-plastic pipeline using a Press is considered professional. It is practically impossible to do it yourself “with your own hands” due to high price on a special tool - press pliers (manual (hydraulic, electric) press for crimping sleeves on plastic pipelines).

In order to assemble heating in your home with your own hands, it is many times more profitable to use compression fittings, or in extreme cases, a push joint, but do not purchase press pliers with attachments “for fabulous money.”
Unless you can rent such an instrument at a reasonable price...

Connecting a metal-plastic pipe with a compression fitting

The oldest and most “problematic” connection is compression (or threaded...). The fittings are usually brass. A thrust ring made of fluoroplastic and steam is installed on the brass fitting rubber seals. But here the seals do not sit so deep in their grooves, so they are easier to tear out of place.

The pipe must be placed on these seals and pushed all the way into the fluoroplastic. Then, the split ring, previously placed on the pipe, under the influence of the nut, compresses the pipe at the location of the rubber seals.

To assemble this metal-plastic pipe connection with your own hands, you will need a pair of keys.
With one wrench, the installer tightens the nut that compresses the ring.
The second adjustable wrench holds the fitting itself. Assembly is very easy, cracking at the joint is normal.

The connection is dismountable - it can be tightened (increase the tightening torque), it can be disassembled, the undamaged fitting can be removed and used in another place, replacing cheap seals.

The joint cannot be walled into the wall, according to the manufacturers' recommendations.

The advantage of docking is the extreme affordability of the fitting in terms of price and complexity of installation. All you need is two keys and a little diligence.

But this connection is leaking. Why?
WITH cold water, as a rule, there is no leak, but on hot water supply or heating, dripping sometimes starts from under the nut. If you tighten the nut, the leak is eliminated for some time, then it appears again.

Leaking from a metal-plastic pipeline at a connection - why, what to do?
Additionally -

Why does a metal-plastic pipeline leak?

The compression joint is the oldest; it was assembled by tens of thousands by many craftsmen. Often the assembly proceeded like this: an oval pipe was forced onto the fitting, crushing and tearing off the seals with a sharp edge and burrs, moving them towards the thrust washer. Then the nut was tightened “conscientiously”.

The cross-linked polyethylene (PEX) was deformed and tightly crimped onto the brass pipe. So much so that without changing the temperature, this place remained leak-free throughout its entire service life. But where significant temperature expansions occurred, the elasticity of the thin-walled metal-plastic pipe was not enough.

When the connection cooled, a gap formed and liquid began to leak. After tightening the nut, the compression intensified, crushing the material, but due to heating-cooling cycles, everything repeated again. Until the next diligent tightening of the nut broke the thread.

What to do to prevent the connection with the fitting from leaking

To prevent the compression connection of a metal-plastic pipe with a fitting from leaking, you need to do the following.

Cut the pipe with scissors. If such a tool is expensive, then carefully use a round file on the file, leveling the cut and removing all burrs.
Align the final section of the pipe (from 5 diameters) manually.
Calibrate with a hand calibrator very carefully to achieve a smooth round hole. At the same time, use a high-quality calibrator to remove the internal chamfer at 45 degrees.
Lubricate the fitting and seals with liquid soap.
Place the pipe onto the fitting and onto the seals without distortion until it touches the washer.
Tighten the ring nut without applying excessive force.

As you can see, it is not very difficult to install a metal-plastic pipe with your own hands without leaks - you just need to comply simple rules connections.
And yes..... - the connection to a proprietary compression fitting, made correctly, with the pipe compressed onto the seals located in the grooves, does not leak at all, including for hot water supply and heating.

Modern technologies are several steps ahead than the inventions of ten years ago. The same goes for the plumbing system. In almost every house, old pipes are actively being replaced, or they have already been replaced with new ones made of metal-plastic. And those who have not yet had time to do this will definitely give preference to this type of material. These types of products are famous for their reliability, quality, and ease of installation. The only thing that may seem unfamiliar, especially if the installation is done with your own hands, is the connection of metal-plastic pipes.

These pipes, made from a combination of metal and plastic, are lightweight, easy-to-use products with high chemical resistance. They are an environmentally friendly product pure material, which is able to operate under a pressure of 10 bar. This material is so flexible that the number of connectors is reduced to a minimum.

Scale and corrosion can be left in the last century, and a service life of 50 years is a good achievement modern technologies. The obvious disadvantage is high coefficient in thermal expansion, lack of fire resistance, deterioration appearance and service life when exposed to ultraviolet light.

Rice. 1

Do-it-yourself methods for connecting pipes

Connecting any metal-plastic pipe requires the use of a fitting.

This connector allows you to:

turn the product in the desired direction, make a sharp turn;
branch plumbing system;
connect pipes with different diameters to each other.

Fittings (Fig. 1), connectors for metal-plastic pipes, come in different types. Depending on the type of use, the joining process is carried out using a crimp nut or a press.

It is important to note: pipes that are laid covertly require the use of only a press fitting, and access to other connection points must be free.

To connect such structures with your own hands, you will need help:

pipe cutter;
calibrator and bevel remover;
adjustable wrench or open-end wrenches;
press jaw (in case of connecting press fittings).

Before you learn how to properly connect metal-plastic pipes, you need to know how to prepare them.

The preparation process is identical for any type of connection:

Measure the required pipe length.
Cut the product only at right angles.
When taking measurements, you need to take into account the length of the entrance of the structure into the fitting.
During cutting, the product may become deformed, but the calibrator will help in achieving the original shape.
The gauge is used to remove the internal chamfer.
The chamfer remover helps in removing the outer chamfer.

Rice. 2

After carrying out the above manipulations, further actions differ from the type of connection of metal-plastic pipes.

Fittings and their varieties

The methods for connecting metal-plastic pipes differ due to the type of connector.

The fitting comes in several types, the most popular are:

compression;
press fitting;
push fitting.

Compression connector (Figure 2)

Connection using a compression fitting is convenient and simple, inexpensive, and can be used repeatedly. The disadvantages include a significant waste of time on the work process; connected elements can only be located in accessible places, and connection points need to be checked periodically.

Alignment of the product is carried out at a rate of 10 cm before and after the cut.
The required length is cut at a right angle.
The end of the pipes is cleaned using a reamer; the calibrator chamfers the entrance to 1 mm.
The nut, then the split ring are put on the product.
The fitting becomes wet.
The product is mounted on the fitting; it must be adjacent to the fitting. The union nut is screwed in completely. The wrench secures the nut, but in no case should you overdo it so as not to strip the thread.

Press fitting connector (Figure 3)

A very reliable type of connection that can be confidently used for installing pipes in concrete walls and under the floor. The downside is the need to use special tools, and the element cannot be replaced multiple times; its dismantling is possible only with part of the product. It is quite difficult to carry out the work with your own hands and without experience.

The joining process is carried out in the following sequence:

The length of the pipe is cut off.
The internal chamfer is removed by a calibrator.
The external chamfer is removed with a chamfer remover.
The calibrator helps to check the diameter from the inside.
The sleeve is removed from the fitting to check the fitting ring and its gasket.
The sleeve, after checking, is inserted back into place.
The pipe must be inserted into the fitting until it stops; it must be visible through the hole in the sleeve.
The sleeve is inserted into the fitting connector, the connection goes all the way.

Rice. 3

Push fitting connector (Figure 4)

This type connections for water supply structures have a number of advantages:

opportunity self-installation, because serious Building tools will not be needed;
installation takes place in short time;
the structure can be hidden in concrete wall or under the floor.

The disadvantages include:

high cost of the element;
The connection of the part must be maintained for at least three hours (at this time the seal takes the desired shape along the radius of the pipe).

The joining process is carried out in the following sequence:

The pipes are cut to the required length.
Using a calibrator, it is used to chamfer the ends, creating an ideal hole.
The push fitting is placed on the prepared product, inserting it all the way.
Another product is inserted on the opposite side of the fitting (connector).
Two products are fixed with a push fitting.

Connection of metal and metal-plastic pipes

In practice, craftsmen often have to deal with the task of connecting metal-plastic pipes to metal ones. Two important assistants are used in the work: a gauge and a compression fitting. You will also need a thread, a washer with a nut, and a cone.

A push-in fitting is a connector that is in a good way for connecting pipes with different diameters, where some elements fit the size metal product, and the second element is the size of the metal-plastic product.

The fitting is selected in accordance with the diameter of the metal-plastic pipe, and the thread is metal.

Connecting metal-plastic pipes to metal pipes requires the following steps:

The metal tube is wrapped in tow.
After winding, the fitting is put on.
A nut and washer are placed on the edge of the metal-plastic product.
The two products need to be connected and the nut must be tightened.

Rice. 4

For correct bending metal-plastic construction can be used following methods:

normal bending with hands;
using a spring, which is inserted inside and makes it easy to bend in the desired direction without defects;
a construction hair dryer gently heats up the product and makes it flexible, but if the part is overheated, the plastic will melt;
A pipe bender is a specially created tool for the purpose of bending a product of any diameter.

Connecting pipeline parts is not a particularly difficult task. Plumbing, underfloor heating system requires preliminary preparation, adherence to technology, understanding of how metal-plastic pipes are connected, selection of quality metal-plastic materials and connectors.

Most specialists and professionals in the field of repair and construction work in Lately It is increasingly recommended to use metal-plastic pipes when repairing and replacing plumbing pipelines.

Such pipes are quite practical and have minimal amount shortcomings. They are quite affordable in price, have a long service life (50 years), are easy and unpretentious in transportation and installation.

And, nevertheless, you should know a few points about how to properly connect metal-plastic pipes in various variations.

Proper connection of metal-plastic pipes cannot be done without the help of appropriate tools. And any competent repairman, plumbing specialist or ordinary owner of a house or apartment knows about this.

If you suddenly need to independently install plastic pipes at home, connecting them in various ways and elements, then you will need the following tools and equipment:

ring wrenches (usually they are used in twos);
sliding key;
pipe bender (usually a simple pipe bender is used);

Pipe cutter

To cut pipes into various sections, separate pieces of pipe from a coil, or other methods of cutting metal-plastic pipes, you can use a special tool - a pipe cutter, which is capable of mechanical manually cut pipes with a maximum diameter of 42 mm.

It consists of handle holders, internal blades made of durable tool steel and a locking bracket, which locks two handles in the closed non-working position.

If this tool is not available, you can use a regular hacksaw or a strong, sharp knife as a pipe cutter.

Any tool capable of cutting metal-plastic will do, but only a pipe cutter can provide a clean and accurate perpendicular cut. After all, for a hermetic connection of pipes, a perfect perpendicular cut is necessary.

Socket and adjustable wrenches

These wrenches are necessary to dismantle and assemble a metal-plastic pipeline and secure them with nuts, fittings and other threaded connections.

Photo: socket wrench adjustable wrench

open-end wrench

It is used only when necessary, but most often when connecting metal-plastic pipes with metal pipes.

Photo: open-end wrench

Caliber

Using this tool, the cutting planes are centered and chamfered from the inside of the pipe. It is thanks to the caliber that the complete tightness of the connection between the pipe sections and the ends of the fitting is ensured.

Photo: caliber

Press jaws

These tools are needed, for the most part, where couplings are used that need to be pressed with pliers.

Photo: press jaws

Pipe bender

In those places where smooth bends of metal-plastic pipes are required or where it is not possible to cut them, they can be bent using a pipe bender. This way, the pipes will remain intact and there will be no need to cut them, which will increase the service life of the pipes.

Photo: pipe bender

Expander

Using an expander, the necessary expansion of the holes inside the pipes is made for permanent connections.

Photo: expander

Connection methods

There are several ways to connect metal-plastic pipes, which are the most optimal options, ensuring complete sealing at pipeline joints, which means efficient and trouble-free water supply.

But in order to use one or another method of connecting pipes, you must first properly prepare the place for their installation and take into account everything important rules installation of metal-plastic pipes.

Preparatory work consists of planning the place where the pipeline will be installed. To do this, calculate all the dimensions and draw all the lines on the walls or floor, where exactly the sections of pipes, their corners, adapters-fittings and other components will be placed.

Important! The beginning of each pipe line should be laid from the water supply point to the faucet, cistern or radiator. The number of corners, tees or crosses should be as small as possible, otherwise their multitude will slow down the flow of water, and, accordingly, the pressure.

All connecting sections of the pipeline must be located in accessible places because they require more frequent inspections and repairs. After the preparation is completed, the assembly of the entire pipeline begins.

Connection with press fittings

In places of turns, corners and various transitions, devices such as fittings are used to connect metal-plastic pipes, which firmly secure the connected sections of the pipeline.

This device is especially convenient when you need to connect the ends of pipes of different diameters. Therefore, fittings that connect pipes with the same diameter are called straight, and those that connect the ends are called transitional.

Press fittings together with the entire piping system can be laid in concrete screed, which is much more convenient in installing heated floors, for example, compared to compression fittings. They come in the following configurations:

Nipple with female thread	Nipple with external thread (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 26×1; 32×1	coupling 16; 20; 26; 32
Elbow with internal thread (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 26×1; 32×1	Elbow with external thread (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 26×1; 32×1	Square (connection of two metal-plastic pipes) 16; 20; 26; 32
Tee with female thread (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 26×1; 32×1	Male Tee (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 26×1; 32×1	16; 20; 26; 32 Transition tee from 16–20–16 to 26–32–26
Cross 16; 20; 26; 32	Elbow (water socket) 16×1/2; 20×1/2	Double square for mounting faucets and other appliances 16×1/2; 20×1/2

Various connections with press fittings help to attach pipes to each other in such a way that the connection is then permanent - this ensures complete sealing of the installation, and hence the efficiency of water supply.

Such examples are, as a rule, press fittings with steel or brass ferrules, as well as fittings with a crimp and slide clamp.

Photo: various connections with press fittings

The connection of metal-plastic pipes with a compression press fitting usually occurs in the following sequence:

cut off the pipe the right size pipe cutter;

Photo: cutting off the pipe

we process the edges of the cut pipe with a gauge;

Photo: processed with a caliber

Photo: putting a crimp coupling on the pipe

insert the fitting using rubber O-rings (for electrocorrosion);

Photo: inserting the fitting

we crimp the coupling with electric or manual press pliers. When working with electric press jaws, do not place your fingers on the metal parts of the coupling or the tool itself. Work exclusively with rubber gloves and hold the device only by its special plastic handles;

Photo: crimping the coupling with electric or manual press pliers

Photo: the coupling should acquire the bright outlines of the rings

Connections of this kind are based on couplings that must be tightly clamped, and therefore they are considered the most reliable and can safely be used in hidden pipeline communications.

Important! The most important rule When working with press fittings, it is necessary to compress the coupling once; repeated clamping of it with press pliers will lead to cracks, thinning of the material, and then failure of the entire pipeline system.

Connection with compression fittings for metal-plastic pipes

Compression fittings are simplest mechanism, which consists of a fitting, a split ring and a union nut. That is why such a pipe connection is considered unpretentious and economical because it does not require the use of additional special tools.

It is enough to use an ordinary wrench, and if necessary, at the joints with compression fittings, the pipeline can be easily dismantled and necessary repairs pipe parts, replacing gaskets on fittings and other work.

Joins using compression fittings there are these:

Photo: connection with compression fittings for metal-plastic pipes

When choosing compression fittings, be sure to pay attention to their manufacturer. It is best to choose fittings from the same manufacturer as the metal-plastic pipes you purchased.

Because many manufacturers produce fittings that are not the correct diameters and may not fit your pipes. When installing a pipeline with compression fittings, no press jaws or any other tools are required.

It is enough to use a wrench and, if necessary, a pipe cutter.

With an already installed pipeline, the third pipe with a compression fitting is connected as follows:

Mark with a simple pencil on the existing pipeline the place where the pipes are cut where the third pipe will be inserted;

Photo: mark the place where the pipes are cut

Photo: cut the pipe at the marked places

we put corrugated insulation on the pipe (if necessary, but usually this is done so that the pipes do not fog up and condensation does not form on them);

Photo: putting corrugated insulation on the pipe

calibrate the ends of the pipe (mandatory item);

Photo: calibrate the ends of the pipe

we put union nuts and O-rings on the ends of the pipe, and then insert the fittings;

Photo: we put union nuts on the ends of the pipe

Using wrenches, we tighten the nuts that fasten the pipes with fittings.

For ease of working with compression fittings, the length of the pipe sections before and after the cut should be at least 10 cm.

Important! The pipes must be cut at right angles and then calibrated on all sides of the gauge: first, 1 mm of the lead-in chamfer is removed, and then with the other side up to the scoring mark.

Before fitting the pipe onto the fitting, lightly moisten it. When tightening the nuts, do not over-tighten them, because this can quickly strip the threads.

With push fittings

Slip-on fittings are just as easy to install as the previous types of connections. First, the pipe is cut in the right place. Then a coupling is put on its end (or two couplings are put on the two ends).

Therefore, the end of the pipe is treated with an expander to slightly widen the hole in the pipe. Next, the pipe is installed on the fitting, the coupling is clamped using press pliers and pressed onto the fitting.

Here important element and a feature of the installation is the principle of pressing a sleeve or coupling of a sliding fitting onto the end of the pipe expanded by an expander, which is put on the fitting.

When you place the compression sleeve on the end of the pipe, it is very important to press the pipe as tightly as possible to the fitting. This is what will ensure the tightness of the connection.

Such methods allow you to connect pipes without welding, glue or any questionable connections, and also to further maintain the integrity of the entire pipeline.

Connection of metal-plastic pipes with metal ones

From time to time, practice shows that when replacing plumbing fixtures in some places, it is necessary to connect metal-plastic sections of the pipeline to metal pipes.

The accuracy and precision of all execution is very important here. step-by-step recommendations. The most common method is to use a metal-plastic pipe when connecting it to a metal compression fitting.

The work should be done in the following sequence:

Using an open-end wrench, screw the fitting onto a metal pipe (cleaned of rust if the pipe is old). To avoid any leaks in the future, use old way- tow and paint. You need to saturate the tow with paint and wrap it around the pipe threads thin layer, and then screw the fitting onto its end;

Photo: screwing a fitting onto a metal pipe

Now start working on the metal-plastic pipe while the paint on the metal one dries. Place the press washer together with the nut on the end of the metal-plastic pipe and calibrate the pipe;

Photo: calibrate the pipe

next, put the end of the metal-plastic pipe on the cone screwed to the metal pipe;

Photo: place the end of a metal-plastic pipe on a cone screwed to the metal pipe

again use the open-end wrench and tighten the nut so that the washer tightly presses the metal-plastic pipe.

Photo: tighten the nut

With polypropylene pipes

In those places where there are connections to boilers, washing machines, heating geysers and other connections that do not require the installation of massive pipes are most often used polypropylene pipes(PPT).

Such pipes are also called plastic because they are made of almost the same plastic. Possible options for connecting such pipes to metal-plastic ones also include devices such as fittings.

These connecting elements perform well both in connections with metal and metal-plastic pipes.

Coupling with internal thread (transition to pipe fittings)	Coupling with external thread (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 25×1; 32×1	coupling 16; 20; 25; 32, etc.
Elbow with internal thread (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 25×1; 32×1	Elbow with external thread (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 25×1; 32×1	Square 45, 90° (connection of two polypropylene pipes) 16; 20; 25; 32, etc.
Tee with female thread (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 25×1; 32×1	Male Tee (transition to pipe fittings) 16×1/2; 20×1/2; 20×3/4; 25×1; 32×1	Tee with identical fittings 16; 20; 25; 32, etc. Transition tee transition to different diameters
Cross 16; 20; 25; 32, etc.	Elbow (water socket) for mounting faucets and other appliances 20×1/2; 25×1/2	Pipe bypass to bypass another pipe when installing in one plane

With radiator

The principle of connecting metal-plastic pipes to radiators mainly consists of using special adapters and fittings, already familiar to us.

There are also several schemes for connecting the pipeline and risers to radiators:

the “bottom-down” scheme is used for hidden piping in the floor. If there are thermostats and valves, special adapters must be used that would firmly fix everything necessary connections;

Photo: bottom-down diagram

lateral connection also requires the use of adapters, chrome-plated or brass tees with metric threads;

Photo: side connection

connection from the floor. With this connection scheme, the “spread” of the vertical front pipes is effectively ensured by a telescopic fitting;

Photo: connection with floor exit

corner connection, or “diagonal” pattern. Not only with this method, but also with others, swivel elbows are also used if necessary.

Photo: corner connection

With tap

Just as we looked at connecting metal-plastic pipes with various other pipe materials and types of plumbing fixtures, connections of metal-plastic pipes with taps are used in the same way.

Fittings are also used here, preliminary calibration of the end of the pipe and connection in this order:

you need to unscrew the connecting fitting;
remove plastic or metal lug nuts and O-rings;
put the clamping nut and sealing rings on the metal-plastic pipe;
insert the pipe tightly into the fitting;
Pull the sealing ring and tighten it with a clamping nut;
the other end of the fitting is connected to check valve, which is pre-installed to the inlet of the tap itself.

With flexible hose

Such connections are usually made where water supply to washing machine, boilers and other devices and structures. The fittings here should be used with fittings that are specifically designed for flexible hoses.

Important! Also at the end water hose There must be a nut that will secure the entire connection to the fitting.

You need to pay attention to this when you buy this or that hose for your future system.

How to disassemble

It must be said right away that not all types of connections can be disassembled without damage and replacement with new connecting elements.

This depends on what technology for connecting metal-plastic pipes was used, what, for example, fittings were used to connect certain sections of the pipeline.

If press fittings or fittings with sliding couplings were used, which were then pressed using press jaws, then such connections are considered non-separable, and therefore their replacement, if necessary, will be done by completely dismantling and cutting off this section with pieces of pipes.

Then you need new components for connecting fittings, as well as an additional piece of pipe.

If connections were used using compression fittings, then unscrewing the clamping nuts will not be difficult. And, therefore, it will be easy to disassemble the entire area where the pipes are connected.

If it flows

To eliminate leaks at the joints, you must first find and determine the cause and nature of the failure.

check that the connecting nut is not loosely screwed on and tighten it slightly until it stops, but not too much so that the thread does not burst or break;
turn off the water supply, unscrew the fitting and check whether the pipe fits tightly into the fitting or whether the pipe fits tightly when it was pressed onto the fitting. If such a problem is discovered, then the pipe must be inserted all the way, and then also screw everything in the reverse order. But this applies only to collapsible connections;
if you have a compression fitting, then check whether the ferrule fits tightly and if not, then press it again with the press pliers. Just don’t overdo it here, so as not to damage the surface of the metal and prevent it from crumbling or cracking;
if you calibrated the end of the pipe with a knife, then water will flow and seep through the rubber fittings, which cannot fit tightly and move out. This malfunction can be easily eliminated by disassembling the connection and calibrating the end of the pipe with a gauge until the end is smooth and installing everything again in the reverse order;
If the sealing rings are worn out or become unusable, then they should be replaced.

Having carefully studied and considered everything possible options connections of metal-plastic pipes using fittings and all kinds of tools, you can easily correct this or that unfavorable situation with your water supply in the house yourself or repair the pipeline yourself.

Careful preparation for work will also help you to repair or install a metal-plastic pipeline yourself and at the highest level.

Video: Secrets

The connection of metal-plastic pipes, as well as other types of polymer parts, is made using fittings Particularly popular today are metal-plastic pipes that can transport liquids with temperatures up to +120 degrees. At the same time, when installing a pipeline, the main issue remains the choice of a reliable and tight connection. How you can connect metal-plastic pipes, and what features the installation of a metal-polymer pipeline has - read below.

- Do-it-yourself installation of metal-plastic pipes for water supply
- How to properly install metal-plastic pipes
- Compression connection of metal-plastic pipes
- How to connect metal-plastic pipes using press fittings
- Push-in connection of metal-plastic pipes with fittings
- Do-it-yourself heating from metal-plastic pipes
- DIY installation of metal-plastic pipes (video)

Installation of metal-plastic pipes may be necessary in the case of laying a new water supply system and organizing a water heating system, replacing an old pipeline, or if it is necessary to extend pipes or change the wiring.

Installing a metal-plastic water pipe can be done by yourself

Today, the following methods of pipeline installation are distinguished:

By welding;
Using special fittings;
Flange connection.

Joining metal-plastic pipes using welding is one of the most difficult methods that takes up a lot of a large number of time: welding is performed in several seams.

The simplest and quick way pipe connections accessible to everyone - using fittings.

Depending on the method of attachment to pipes, fittings can be crimp, flange, threaded or welded. There are fittings different forms, sizes and types. But what they all have in common is that they make it possible to quickly and reliably connect one pipe to another.

There are also tap fittings that allow you to shut off the water supply. Assembly water pipes with flanges is rarely used in everyday life due to its bulky appearance.

How to properly install metal-plastic pipes

When installing a pipeline, various connectors are used: coupling, cross, corners. This allows you to do any wiring: make pipeline turns, branch lines, connect pipes with different diameters. A special spring is used to bend the pipes. Do-it-yourself installation of a metal-plastic pipeline has its own nuances.

In order to install a water supply system, it is not at all necessary to always resort to the expensive services of specialists

So that the pipeline is sealed and reliable, the installation should be carried out taking into account the following recommendations:

Metal-plastic should be installed only in places with limited access to sunlight (no direct UV rays).
Care should be taken to ensure that the pipeline is not exposed to mechanical and thermal external influences.
Hidden laying of a metal-plastic pipeline requires the presence of inspection hatches at the points where the pipes are connected with compression fittings.
The pipes should be secured to the wall using hangers and supports.
Installation of the pipeline through the walls of buildings is carried out using special sleeves with a diameter exceeding inner diameter the pipes themselves by 5-10 mm.

In addition, you need to ensure that during the installation process, scratches, dents and other defects do not form on the pipes. Metal-propylene pipes should only be unpacked with blunt objects, and a soft pencil or marker should be used for marking.

Compression connection of metal-plastic pipes

In private construction and agriculture Most often, a compression connection is used. This is done using special PE fittings with a press-fit sleeve.

The main advantage of this connection is that no special equipment is required during installation, and if necessary, it is possible to dismantle any connection

You don't need a special tool to make the connection.

Fittings with a diameter of 2-5 cm are installed manually. For larger sizes, a chain wrench is used. Wrenches can also be used to tighten fittings.

The compression technology for connecting pipes involves:

Pipe cutting. You need to cut at a right angle using plumbing shears for metal, technical scissors for cutting polymer pipes.
Cleaning pipes, removing burrs and rounding edges. The surface that will be inserted into the fitting must be clean and free from defects. Otherwise, the pipe may, over time, begin to leak. Installing the blue nut. Nut of blue color remove from the fitting and put on the pipe.
Installing the white clamp ring. Installation is carried out with the thickened end of the part towards the long end of the pipe.
Fitting installation. The element is put on the pipe and the metal crimp ring is pushed until it stops.
Tightening the blue nut. It is better to tighten the nut first by hand and then using a tool.

The disadvantages of compression connections include the fact that after some time they have to be pulled. At the same time, stretching fittings can be very difficult. Especially if communications are located under the floor. Otherwise, the base will have to be dismantled to carry out the work. To avoid broaching, press fittings should be used for connections.

How to connect metal-plastic pipes using press fittings

Press fittings are special devices for connecting plastic pipes, which differ high strength and durability comparable to the service life of the water supply system itself. A press fitting consists of a body with a fitting and seals that isolate the ring and ferrule. Thanks to this design, the fitting does not leak. Today there are a large number of press models that allow you to implement any pipe layout.

Compression type brass compression fittings consist of components such as a fitting, a split ring and a union nut.

Press fittings are installed quickly and easily using special tool– crimping pliers.

Pincers can be either manual or hydraulic. Before you go shopping for a tool, you should determine the diameter of the pipes.

In order to connect two metal-plastic pipes with a press fitting correctly, you need to:

Cut the pipe at the desired location at a right angle.
Adjust the diameter of the pipe and remove the chamfer using a chamfer tool.
Place a stainless steel sleeve on the end of the pipe.
Insert the fitting into the fitting pipe.
Grab the tension sleeve with pliers and bring the tool handles together until they stop.

You should work carefully, as it will be impossible to re-crimp the fitting, and due to a poor-quality connection, the pipe may begin to leak. Then you will need to repair the metal pipe.

Push-in connection of metal-plastic pipes with fittings

Push-in fittings are special connecting devices that have two rubber seals in their design. This ensures a tight connection. These connectors are made of brass, which makes the fittings resistant to corrosion.

Fittings differ not only in design, but also in purpose, it becomes quite obvious that knowledge is necessary to select the appropriate material

Push-in fittings have a special dielectric gasket in their design, which makes them electrically non-conductive.

Even beginners can install the devices. The design of collet fittings requires the presence of a special ferrule, which allows the clamp to be made evenly without deforming the structure. After all, it is quite difficult to straighten such a pipe with defects.

There are several types of collet connectors:

Angle for metal-plastic pipes (internal - B type and external - H type);
Straight fitting (allows you to connect pipes in series);
Tee (can connect three pipes together either in series or at right angles).

The push-in connection is made using clamping pliers. You can also use a special press for fittings. In this case, the pipes should be well flared before joining.

Do-it-yourself heating from metal-plastic pipes

Organization heating system from metal-plastic pipes - this is quite labor-intensive work. In order to make the connection and further connection of pipes, you will need to stock up wrenches, flaring machine and springs for bending pipes. Before you start assembling the system, you should clearly determine the location of the boiler, pump, safety group, expansion tank, shut-off equipment, radiators. It should be taken into account that attaching any shut-off valves between the boiler and the set of safety elements is strictly prohibited.

It’s quite easy to install heating from metal-plastic pipes with your own hands.

A mechanical filter must be installed in front of the forced circulation pump.

This will protect the working elements of the pump from rapid wear. The filter, like the pump, should be installed on horizontal section systems.

Today there are several heating pipe layout schemes:

Single-pipe;
Collector;
Two-pipe.

The first scheme assumes the presence of fewer pipes. But the further the pipes are from the boiler, the lower the temperature in them will be. Two-pipe system suggests how wall mounting, and installation of pipes in the floor. It is more efficient, just like the collector one, in which there will be significantly more pipes in the distribution than in the first option.

DIY installation of metal-plastic pipes (video)

Plumbing is something without which it is impossible to imagine a comfortable life. Today, metal-plastic pipes are used to transport liquids, which can be connected in various ways. You can install a metal-plastic pipeline for water supply and heating yourself. The main thing is to follow the advice of professionals and pipe connection technology!

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Zaporozhye National Technical University (ZNTU)