Installation of metal-plastic pipes. How to connect and install metal-plastic pipes Working with metal-plastic pipes

Metal-plastic pipes are polymer products that are widely used in the installation of plumbing communications. They are an excellent alternative to steel counterparts; they are superior to them in most respects performance characteristics, including cost and durability.

This article discusses installation metal-plastic pipes. You will learn what methods of connecting metal-polymer products exist, how to install them yourself and what tools are needed for this.

Contents of the article

Design Features

Metal-plastic pipes have a multilayer structure, which consists of 5 separate layers that perform different functional tasks:

outer and inner layer of polyethylene;
intermediate reinforcing layer of aluminum foil;
shells made of aluminum and PE are connected by two layers of adhesive, resistant to high temperatures.

For the manufacture of metal-plastic products, two types of polyethylene can be used - PEX (cross-linked polyethylene) and PE-RT (thermal stabilized polyethylene). These modifications of PE differ in manufacturing technology; in practice, the differences between them are that PEX is more resistant to deformation during long-term heating, which makes PEX pipes the preferred choice when installing underfloor heating and hot water supply systems.

The foil sheath lying between the inner and outer PE layer ensures zero vapor permeability of the pipes, which in turn minimizes corrosion problems heating devices(boilers, radiators) due to the penetration of oxygen into the coolant.

Metal-plastic pipes can be used in the following systems:

cold and hot water supply;
radiator heating;
warm floor;
pipelines for gas supply.

The operating temperature maximum for metal-plastic products is +90 degrees, they can withstand working medium pressure up to 20 mPa.

Metal-polymer pipes are produced in the diameter range of 16-53 mm. Products with a diameter of more than 40 mm are practically never found in household use, while segments up to 32 mm are most in demand. The cheapest and most commonly used are 16 and 20 mm metal-plastic pipes, the cost of which is minimal.

The wall thickness can be from 2 to 3.5 mm, the maximum bending radius is 80 mm (when bending manually) and 40 mm (using a pipe bender).

Advantages of metal-plastic pipes

The advantages of metal-plastic products that distinguish them from polymer analogues include:

Ideally smooth walls (roughness coefficient 0.006), which guarantees quiet water supply and no problems with passage even after long time operation.
Full resistance to corrosion and chemically aggressive substances.
High mechanical strength, resistance to bending and tensile loads, crack resistance.
Minimum weight, low cost of the pipes and connecting elements themselves, the pipeline is extremely easy to install with your own hands.
The products bend easily and, due to the aluminum layer, perfectly hold the given shape.
Durability – product lifespan exceeds 50 years, and maintainability.
Aesthetic appearance– after installation, the pipeline does not need to be painted.

Among the disadvantages, we note the tendency of the material to linear expansion. To prevent problems associated with it, the installation of metal-plastic pipes must be carried out in compliance with a number of rules, namely:

For fixation, you cannot use rigid fasteners, since when clamping an expanding line, the tension in the material increases greatly; sliding clips must be used;
It is important to observe a step between clips of 40-60 cm, which does not allow the pipeline to sag between the fasteners.

In general, in terms of overall performance qualities, metal-plastic pipes are superior not only to metal ones, but also to most polymer analogues.

Do-it-yourself installation of metal-plastic pipes (video)

Installation of metal-plastic pipes

Installation of metal-polymer products is carried out using two types of fittings – compression (threaded) and press, high-temperature welding is not used to connect them, since only composite pipes can be properly soldered together.

The main advantage of fitting connections is extremely quick and easy installation, which does not require special skills. We also note that using fittings, metal-plastic pipes can be connected to other types, including steel, copper, etc.

Installation with compression fittings

The compression fitting allows, if necessary, to be dismantled, which is why its cost is higher than that of its press counterpart. The design of the compression fitting consists of three parts:

fitting (metal or);
ferrule ring;
union nut.

This fitting is not required for installation. special tool– the union nut of the fitting has a thread, which allows it to be tightened using a universal wrench or an open-end wrench of the appropriate size.

Compression fittings are available in a wide range of standard sizes; you can purchase angles, adapters, crosses, etc.

Note that compression fittings require periodic repair and maintenance, since due to the tendency of metal-plastic to linear expansion, leaks may appear at the junction of individual parts of the pipeline, which are eliminated by tightening the fitting. This places a limitation on the possibility hidden installation pipelines, which involve concreting pipes inside walls and floors.

To connect the segments using compression fittings you will need the following tools:

(can be replaced with a hacksaw or grinder);
fine-grained sandpaper, file;
calibrator

Do-it-yourself installation of metal-plastic pipes is carried out according to the following instructions:

The pipe is straightened, measured and the required cut location is marked.
According to preliminary markings, the pipe is cut at a right angle.
Burrs are removed from the end part of the cut using a file or sandpaper, then the product is given round shape through a calibrator;
A union nut and a ferrule ring are placed on the segment, which is placed at a distance of 1 cm from the cut.
The pipe is put on the fitting fitting, after which the union nut is manually tightened. When the nut slows down, it is pulled out 3-4 turns using open-end wrenches.

When tightening the fitting, it is important not to overdo it - after assembly and, if necessary, problematic connections are tightened.

Installation using press fittings

Press fittings give permanent connection, which does not require repair or maintenance, which allows for hidden installation of pipelines. Such fittings can withstand a pressure of 10 bar, and their service life reaches 30 years.

To use press fittings, in addition to a pipe cutter, calibrator and sandpaper, you will need press pliers. This is a tool used to compress the fitting sleeve around the pipe. The cost of press jaws varies between 1-3 thousand rubles; the tool is offered in the range of all companies that sell metal-polymer products.

The technology for installing metal-plastic pipelines is as follows:

The pipe is marked and cut at right angles into sections of the required length.
Using a reamer or sandpaper, the cut area is cleared of burrs.
The calibrator eliminates ovality that occurs during cutting.
The segment is inserted into the fitting all the way so that it is placed between the fitting and the crimp sleeve.
Using press pliers, the sleeve is pressed until the tool makes a characteristic click. If the compression is performed correctly, two rings of equal size are formed on the surface of the sleeve.

There are fittings in which the ferrule and fitting come separately. In this case, you will need to first put a sleeve on the pipe, then fix it on the fitting, move the sleeve to its extreme position and crimp it with pliers.

Pipes made from a symbiosis of metal and plastic are produced for the construction of intra-house highways. The new products made it possible to assemble a water supply and heating system yourself, without involving plumbers. Pipelines serve for a long time, are installed extremely simply and quickly, without creating problems even for inexperienced craftsmen.

We will tell you everything about the specifics of using metal-plastic products and methods of connecting pipelines assembled from them. The article describes in detail the negative and positive aspects their use. Here you will learn how to install trouble-free systems.

Metal-plastic (metal-polymer pipes) are composite products for the production of which they are used various types materials. Such elements have an attractive appearance, good wear resistance, elasticity, and strength.

Metal-plastic pipes are distinguished by high consumer qualities (strength, flexibility, resistance to high temperatures and aggressive substances), as well as an aesthetic appearance

Typically, a pipe consists of five layers. A durable polymer, usually cross-linked polyethylene, is used as a supporting base. It gives smoothness inner surface, protecting it from blockages, and also contributes to the strength of the product.

An adhesive is applied to the core, on which aluminum foil that stabilizes the pipe is attached (it also prevents the ingress of oxygen). The connection is secured by butt or overlap welding.

The design of the metal-plastic pipe involves the use of five layers various materials: two layers of polyethylene, two layers of glue, a layer of aluminum foil

The fourth layer is also applied with glue, to which the outer covering – polyethylene – is connected. white, providing protection to the product and giving it an aesthetic appearance.

Technical characteristics of pipes D 16-20 mm

Here are the data typical for metal-plastic pipes of common diameters (16 and 20 mm):

The wall thickness is 2 and 2.25 millimeters, respectively; The thickness of the aluminum layer is 0.2 and 0.24 mm.
One running meter weighs 115 and 170 grams and holds a volume of liquid equal to 1.113 and 0.201 liters.
The thermal conductivity coefficient is 0.43 W/m K, the expansion rate of metal-plastic is 0.26x10 4 per 1 degree Celsius, the roughness coefficient is 0.07.
When the material breaks transversely, the strength coefficient is 2880 N.
The strength of the connection between the adhesive layer and the foil is 70 N/10 sq. mm, the strength coefficient of the aluminum welded layer is 57 N/sq. mm.
Metal-plastic pipes can operate even at +95 o C, briefly withstanding temperatures of +110-130 o C.
Within the temperature range from 0 to +25 o C, the system operates at a pressure of up to 25 bar, and at +95 o C it can withstand a pressure of 10 bar.
The tightness and integrity of the metal-plastic pipe is broken under a load of 94 bar (at +20 o C).

At correct installation and compliance with operating rules, products made of metal-polymers can last 50 years or more.

Advantages and disadvantages of metal polymers

The advantages of such products include:

ease of installation: connections various categories metal-plastic pipes are carried out quickly and easily;
high heat resistance (water heated to 100°C can be transported);
reasonable price (metal-polymer pipes are cheaper than metal and most plastic analogues);
high strength and ring stiffness;
resistance to corrosion and aggressive environments;
reluctance to form deposits and blockages;
aesthetic appearance;
high throughput;
low thermal conductivity;
sufficient plasticity;
possibility of easy repair;
durability.

The main disadvantage of such products lies in the fact that the metal and plastic from which the pipes are made have different expansion rates. Regular temperature changes of the agent in the pipes can lead to weakening of the fastenings, which causes leaks in the structure.

To avoid this, experts advise, when performing installation, to always provide a certain margin at pipe joints. It will also be useful because metal-plastic systems do not withstand water hammer well.

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What materials will be needed?

To lay the pipeline, it is important to stock up on the following components:

pipes (coils, measured sections);
various fitting options (bends, tees, corners), with the help of which individual sections of pipes are transformed into a single system;
fastening elements - collapsible clamps and clips, with the help of which metal-plastic structures are fixed on supporting surfaces, most often on the wall.

It is important to choose everything in advance necessary materials and tools to then carry out all the work smoothly.

He will introduce you to the range of metal-plastic products for pipeline assembly.

Pipe line marking

Before starting work, it is important to think about how the pipes will be placed.

When developing a circuit, it is advisable to:

Draw pipeline lines directly on the walls of the room where it is planned to be laid, which helps visualize the structure.
As a starting point, use the connection point of the pipe to the tap or radiator, which must already be installed before installation begins.
Minimize the number of tees and crosses that affect pressure stability, and also minimize the number of other fittings.
For corner laying of metal-plastic pipes, you can use a pipe bender or corner fittings.
All connecting elements should be provided with free access, since threaded fasteners need periodic tightening to avoid leaks.

The installation of connecting elements must be carried out after completion of calculations and marking of the structure.

Overview of fittings for metal-plastic systems

To prepare for work, it is important to cut the pipes into sections of the required length, and all cuts must be made strictly at right angles. If the pipe becomes deformed during the cutting process, it must be leveled with a gauge (it will also help remove the internal chamfer).

To connect metal-plastic pipes of different categories into a single structure, connecting elements are used - fittings that differ in design, size and fastening methods

Various are used for installation of the structure; we will dwell on them separately.

Option #1: collet

Push-in fittings consisting of a body, a ferrule, rubber gasket, have a detachable design, so they can be used several times. The thread of the parts allows them to be combined with household appliances.

To connect the connecting elements to the pipe, you need to put a nut and a ring in series. Insert the resulting structure into the fitting and tighten the nut. To make it easier for the pipe to pass into the connecting element, it is advisable to wet it.

Option #2: compression

Widely used for connecting pipes are parts that can be called conditionally detachable. Before installation, it is important to ensure the presence of o-rings and dielectric gaskets, which should be located on the shank of the part.

Installation of metal-plastic pipes is not difficult even for non-professionals. You don’t have to be a plumber to lay water supply pipes with your own hands: just carefully read the laying rules.

Choosing an installation option for a metal-plastic system

If you are determined to install and install metal-plastic pipes yourself, decide in advance on the option for laying the pipeline. It happens:

hidden (the system is “hidden” in the wall);
open (it runs along its surface);
combined (combining both options).

The required method is selected taking into account:

purpose of the premises;
the need to have access to the structure.

Metal-plastic pipes are fastened to walls using special clips. For plumbing, single ones are usually used, for heating - double ones (for two-pipe systems). We select them taking into account the diameter of the product and fasten them to the wall with dowels or self-tapping screws.

To prevent the pipeline from sagging, the distance between the fasteners is 1 m or less. For heating installation, a step of no more than 0.5 m is recommended (so that the circulation of the coolant is not disrupted). The bends are fixed on both sides.

Hidden

This is an aesthetic, but labor-intensive option, usually used in bathrooms, as well as in rooms where the possibility of damage to the surface of the structure is expected. To cover it inside the walls, channels are dug, a system is laid and the recesses are sealed finishing materials, leaving access to the fittings (using “windows” or removable panels).

It is not advisable to use a hidden gasket:

For load-bearing walls(it is forbidden to ditch them);
in an already finished room (you will have to dismantle and then restore the wall covering).

The main advantage is that the type of pipeline does not spoil the design of the room.

Open

Open wiring should not be done if:

there is a possibility of mechanical damage to the surface of the structure;
they have access to ultraviolet rays (this is harmful to them).

Advantages of the method:

the joints are visible - easy to unscrew if necessary to clean or replace a fragment;
no damage to the finish is caused (can be installed in rooms where repairs have already been made).

Fastening with clips to the wall should be done as smoothly as possible, remembering that the pipeline is visible: slanting lines are not pleasing to the eye.

Combined

The pipeline is laid along the surface of unformed walls and covered with special false panels or boxes are mounted. The method requires an accurate idea of the future design of the room: boxes and panels should not detract from the appearance of the room, but should fit organically into the design.

Design and marking for material calculation

Work with any metal-plastic pipes (for plumbing or heating) should begin with developing a diagram of their placement:

Draw the lines of future installation directly on the walls - visualization makes it easier to understand where everything will be located.
“Starting point” is the point of connection to an already installed faucet or radiator.
Try to get by with as few fittings as possible (the fewer there are, the more stable the water pressure).
If a corner gasket is required, decide whether to bend or use corner fittings.
Even at the markup stage, remember: all connections must be accessible. It is also necessary to be able to tighten the fasteners if necessary.
All connecting elements are installed after the markings and calculations are completed.
By wiring diagram(draw clearly!) The length of the pipeline, the number of fittings and fasteners are calculated.

Selection of pipe for installation

The least requirements apply to products intended for cold water supply. As for hot items, you should take goods labeled PEX (cross-linked) and PE-RT (linear) polyethylene. Before purchasing, check what the normal and maximum pressure indicators are for your water supply.

Look at the certificate to see if the product meets hygienic requirements, evaluate the appearance for dents, scratches, and other defects.

Plumbing system

For home plumbing, pipes of 16 and 20 mm in diameter are most often used. If the main wiring is assembled from 20 mm, then the connections to the mixers, household appliances, the bathtub is made from 16 mm.

Heating system

Choosing products to create heating structure, take into account the availability of quality certificates. Products must be designed for working pressure from 6.6 atm and temperature 95 °C and are not made of polyethylene low pressure: It is neither durable nor heat resistant. Do not purchase products marked PE-RS, they will melt if the coolant temperature exceeds 75 °C!

Selecting a fitting for joining pipes

When you install a water supply system from metal-plastic pipes yourself, you need to pay serious attention to the choice of fittings: responsibility for leaks falls on you! Fittings are considered a “weak point”, do not skimp on cheap options.

Compression fittings are simple, but less reliable than press fittings. Please note that hidden gaskets require the use of press fittings only. In other cases, be sure to ensure free access to compression devices.

Preparing tools and supplies

To install the structure, you will need a small set of tools (all of them should be at hand):

pipe cutter or sharp scissors (for a tight connection, a strictly perpendicular cut is necessary);
calibrator (needed for centering the cutting area and chamfering);
sliding and open-end wrenches (they are used to tighten nuts in compression fittings)
press pliers (they manually crimp press fittings);
pipe bender (allows you to change the configuration of pipeline segments without using corner fittings - it is better to use it if there are many corner connections).

Required materials:

the bay itself, measured pieces of the required length will be cut from it;
different types of fittings (tees, bypass, corner) for wiring and creating a single design;
fastening elements (clamps and clips from the manufacturer) for fixing pipeline sections on supporting surfaces.

Laying metal-plastic pipes

How to correctly install a metal-plastic pipe:

cut a fragment of the required length;
use a calibrator to adjust the shape of the cut;
chamfer from both surfaces - outside and inside - simultaneously;
Unscrew the fitting (remove the nuts from the ends, O-rings from the fittings);
if the fitting is compression, put a nut with a sealing ring on the prepared fragment, connect the pipe and fitting, secure the connection with the nut - first tighten it by hand, then use a wrench;
if a press fitting is used, first disassemble it and make sure it is not defective (remember that you can’t “unscrew it back”), then place the prepared fragment on the fitting, assess the seating depth - for this there is a hole on the sleeve. Then use press pliers to press the connecting sleeve twice, forming two annular compressions.

To form the desired bend, you can use a pipe bender or bend it with your own hands, heating it with a construction hairdryer: in several steps, without making sudden movements and remembering the permissible bending radius (indicated in the technical specifications). The thumbs of both hands are positioned along the product during this action. The inner and outer layers of the product must not be deformed!

To simplify the workflow, you can first assemble the individual parts of the system. Then install the parts of the structure in the appropriate places and connect them. Each pipe is fixed to the wall using hanging and supporting elements from the manufacturer. Installation of metal parts is carried out with gaskets made of special soft materials. After sequentially combining all parts, connect them to the “hot” and “cold” risers.

Pressure testing of the water supply system

When the installation of a water supply system made of metal-plastic pipes is completed, it is necessary to check it for leaks using the pressure testing process:

It is necessary to shut off the test area filled with water to seal it (using taps/valves).
Connect a pump to the connection pipe of one of the taps (for home system water supply is suitable manual, low-power).
Using a pressure testing pump, pump water into the selected area at a pressure greater than the calculated operating pressure, then turn off the pump and record the pressure gauge readings.
Maintain the system under pressure for some time - at least half an hour.
Then the current pressure gauge readings are compared with the original value. If the two values are different, something has gone wrong, there is a leak.

If you have an open gasket, the problem area can be detected visually. After eliminating the malfunction, you will have to re-test it.

Metal-plastic pipes are widely used today in the installation of heating, water supply and sewerage systems. From the name it is already clear that these pipes are made of composite material.

They consist of a layer of metal enclosed in a plastic shell. Between the shell and metal surface There is also a layer of special glue. This design can withstand significant pressure and temperatures up to 95 degrees. At the same time. It is absolutely safe for health, does not corrode and has a fairly aesthetic appearance.

The advantage of this material is, first of all, its low cost, ease of installation, and hygienic cleanliness.

Preparation stage

If the choice fell on metal-plastic pipes for installing a water supply system, then it is necessary to determine the amount of material that will be required for the work.

This type of material is supplied in coils from 50 to 200 m long, but you can purchase any number of linear meters of metal-plastic pipes in the store. The length of the internal water supply system is measured from the riser.

Installation is carried out along the walls, slightly above the floor level, so you need to measure the distance along the length of the wall from the riser to the intended installation location of the farthest crane in your room.

Then to the resulting value, add the height from the floor to the mounting hole of taps, toilets and washing machines. As a result, you get the total length.

It’s immediately worth noting that any pipe connection significantly increases costs, and is also a place critical for the reliability of the system, so it is very important to correctly calculate the length of the entire system at the preparatory stage.

After the measurements are taken, the resulting value in meters should be rounded up to a whole number. Then you need to decide on the diameter.

Metal-plastic pipes have an outer diameter ranging from 16 to 63 mm. When installing a water supply system inside a living space, the most the best option is 20 mm. A 16 mm pipe is more suitable for installing a “warm floor” system, as well as for piping from the main line to taps and mixers.

If it is necessary to install a water supply to a private house from the water supply network, then the maximum diameter of this material is selected.

Installation technology

types of fittings

When installing a water supply system from metal-plastic pipes, you cannot do without additional materials and tools.

Tools that may be needed when working:

pipe cutter or hacksaw for metal;
calibrator;
roulette;
wrenches;
pliers or press (when using press fittings);

The first thing you should purchase from materials is fittings and clips for fixing the pipe to the floor or wall.

Fitting– this is the connecting part of the pipeline, used during the installation of a water supply system, used for branching, transition to another diameter, and also serves to connect pipes of dissimilar materials. The purpose of the fitting depends on its design. If you need to connect a metal-plastic pipe to a tap or metal pipe, then select the collet-thread system fitting. If between each other, then a collet-collet system is used.

In addition to collet fittings, there are designs with a crimping mechanism, which fixes a metal-plastic pipe by circularly crimping the pipe with special pliers or a press. This option is more reliable in operation, installation takes less time, but the cost of the work increases significantly, primarily due to the need to purchase special tools.

Installation using push-in fittings

device

The connection process takes very little time and consists of the following steps:

If necessary, then a piece of pipe is cut off with a special pipe cutter or a hacksaw for metal.
Place where the separation was made is leveled using a calibrator
The fitting must be disassembled. Then the fitting nut is put on the pipe with the thread facing the edge of the pipe. The nut should be moved away from the edge by 20 - 30 mm.
On the pipe put on the collet ring and also move it a little from the edge.
Fitting fitting is inserted into the pipe until it stops; however, care must be taken not to damage the rubber seals.
The nut is tightened.

On the other hand, the fitting connects threaded connection with a tap or metal pipe, or, if it is a collet-collet system, then with a metal-plastic pipe. The fitting can also be in the form of a tee for a branch in the system. If a tee is used to branch from the main line to a tap, then a tee can be used: 20*16*20.

Connection using a press fitting

You will need pliers or a special electric press. Pliers can be mechanical, which perform crimping using human muscle power, and can also have a hydraulic mechanism.

Installation occurs in the following sequence:

The pipe is cut.
The hole is aligned using a calibrator
On a metal-plastic pipe put on a sleeve for crimping.
To the fitting fitting the pipe is put on.
Crimping in progress using a manual or electric press.

If the connection process was carried out correctly, then the extruded rings should be visible on the crimp sleeve along the entire circumference.

The result is a very reliable connection that does not require maintenance during operation. When installing heated floors, only press fittings are required. The use of this connection technology allows you to significantly save time on installation, which can be especially noticeable when carrying out a large volume of work.

Pipe fastening

clips

After the water supply is assembled, you will need to install it on special clips, which must correspond to the diameter of the pipe of the appropriate size. First of all, the clips are mounted on the wall using screws.

Then the pipe is taken and forcefully inserted into these fasteners. This is the only thing possible option fastenings

The use of rigid clamps for fixing is strictly prohibited; pipes must be able to slightly change their geometry when the temperature of the liquid that circulates inside changes. Only clips perform this function well.

How to bend a metal-plastic pipe?

The water supply cannot be installed only in a straight line. Turns are inevitable when constructing a water supply system.

It is not necessary to purchase a tool called a pipe bender if you only need to change the direction of the water pipe a few times. When using a pipe with a diameter of 16 mm, this is done manually. You just need to follow some rules that apply to all diameters.

The bending radius should not be less than 5 pipe diameters, for example, for a 20 mm pipe, the minimum turning radius is 100 degrees.

If the diameter is more than 16 mm, then in order to correctly bend, you need to use a special steel spring, which can be purchased at almost any building materials store.

The bending is done in this way. The spring is inserted into the pipe cavity and moves towards the bend. If you have to bend at a considerable distance from the edge, then a rope should be tied to the spring. This is required so that after completing the bending procedure the spring can be pulled out of the pipe.

You can also move the spring a considerable distance using a powerful neodymium magnet, which, when in contact with the pipe, must be guided along to the point of bending. When the middle of the spring is aligned with the middle of the intended bend, the pipe should be bent manually. The spring is then pulled out using a rope.

If you need to bend a metal-plastic pipe large diameter, then to the method indicated above, you need to add 1 more spring, which is put on with outside, and also leads to the middle of the bend.

A metal-plastic pipe can be bent using sand or salt. To do this, dry calcined sand or salt is poured into the cavity of the pipeline, then both ends of the pipe are securely closed with plugs, and a bend is made in the right place. After completion of the work, the sand is removed.

Installation work you can do it yourself, the main thing is not to rush, and if you need to perform any action for the first time, for example, bending, then it is better to first practice on some unnecessary piece of material.
All work must be carried out only when the water supply from the riser is turned off.
Don't be afraid to use it when conducting repair work modern materials. Plastic that is used in building materials, if not heated above certain temperatures, does not emit harmful substances. Of course, this is only true for certified products purchased at specialized retail outlets.

Metal-plastic (metal-polymer) pipes are composite pipes made from polymer pipe, reinforced with metal.

They are strong, durable, easy to install, resistant to aggressive environments and are often used in the construction of water pipelines, heated floors, systems for transporting compressed air and various liquids (including chemically aggressive ones), for laying electrical wires and cables.

outer protective layer made of cross-linked polyethylene;
inner layer made of food-grade plastic;
between the layers of polyethylene there is a reinforcing aluminum shell;
aluminum and polyethylene layers are bonded together with adhesive layers.

Photo: structure of a metal-plastic pipe

This design provides unique properties metal-plastic pipes:

metal-plastic pipes are easily bent, cut and hold their shape, thanks to the aluminum core;
the outer and outer layers of polyethylene are highly resistant to corrosion and protect the inner shell of aluminum from moisture and aggressive environments;

These design features determine the ease and convenience of installation of metal-plastic pipes, their reliability, durability and wide application conditions.

Specifications

To the main technical specifications include:

pipe diameter. Metal-plastic pipes with diameters from 16 to 53 mm are produced. Pipes with a diameter of over 40 mm are practically not used in housing construction; pipes with a diameter of 40 and 32 mm are actively used when laying out the water supply network in a private house. The most popular and cheapest pipes are 16 mm, fittings for them are much cheaper than others. However, they and 20 mm pipes should only be used in central water supply networks at normal pressure in the water supply network;

Photo: pipe diameters and table of pipe diameters for heating

pipe wall thickness(can be 2 or 3.5 mm);
permissible bending radius. Lies in the range of 80-550 mm with manual bending and 50-180 when using a pipe bender.

Photo: pipe bend

Connection methods

For connection, special connectors (fittings) are used.

Fittings for these pipes are of two types:

compression threaded fittings;
press fittings.

Benefits of using fittings

quick and easy installation;
no welding required;
the labor intensity of the process of installing plumbing and heating systems is reduced;
no special skills are required to perform the work;
A very simple way to connect metal-plastic pipes with other types of pipes (steel, copper, plastic).

Compression Threaded Fittings

Compression fittings with threads for metal-plastic pipes are the most expensive. They allow you to make dismountable connections.

Available large assortment dismountable compression fittings of various types.

Types of threaded compression fittings:

corners: nut-collet, collet-collet, collet-fitting;
adapters: fitting-collet, nut-collet, collet-collet;
crosses;
tees: three collets; fitting-two collets;
water sockets: two collet nuts and a collet nut.

No special tools are required to install compression fittings. They are threaded and for their installation it is enough to have open-end or adjustable wrenches on hand;
Compression (crimp) fittings for metal-plastic pipes are recommended for connecting pipes of cold water supply systems.

Compression fitting for metal-plastic pipes consists of:

fitting;
compression ring;
union nut.

Photo: compression type connection

Press fittings

During installation, press fittings are widely used when installing hot and cold water supply systems, when installing heating systems and heated floors.

Photo: press fitting diagram

This is due to the fact that press fittings have the following advantages over compression fittings:

hidden laying of pipelines is allowed;
Pouring with concrete is allowed;
the connections are permanent. There is no need for annual preventive tightening of nuts at pipe joints;
maximum permissible operating pressure at joints up to 10 atm:
The service life of a connection using a press fitting is up to 50 years.

Their use is limited only by the need to use special presses (manual or automatic) during installation, which are not cheap.

A wide range of press fittings are available, allowing you to assemble a pipeline of any required configuration:

Photo: press fittings

tee fitting;
square;
coupling;
water socket;
cross.

Advantages

light weight;
durability (service life up to 50 years);
high throughput (one third higher than the throughput of similar metal pipes);
economical and simple installation;
resistance to aggressive environments;
resistance to clogging;
low thermal conductivity;
high plasticity;
high maintainability and ease of repair;
are not able to conduct stray currents (antistatic);
aesthetic appearance.

In order for the bathroom to have a neat appearance, you need to install a screen under the bathtub with your own hands, for example, from plastic panels. Read about this in the article:.

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Flaws:

are afraid of ultraviolet radiation;
mechanical strength and thermal resistance are lower than the corresponding parameters of copper and steel pipes;
cannot be used as grounding conductors;
accumulate electrostatic charges;
require periodic maintenance (when using compression fittings);
When using compression connectors, it is unacceptable to place them in concrete screed, it is necessary to provide access to the connectors for their periodic tightening;

Compression fitting installation

Required tool:

adjustable or open-end wrenches;

Photo: adjustable wrenches

Photo6 scissors for cutting metal-plastic pipes

Photo: pipe calibrator

Installation of compression fittings on metal-plastic pipes is carried out in the following order:

the pipe is straightened in a section of 10 cm on both sides from the cutting site;
the location of the cut is outlined;
at the intended location the pipe is cut at a right angle;

Photo: cutting a metal-plastic pipe

the cut end is sanded with sandpaper and given the correct rounded shape using a special reamer (calibration);
a fitting and a cut compression ring are put on the pipe;

Photo: installation

the fitting is wetted in water and put on the pipe so that the end of the pipe evenly touches the fitting;
The nut is tightened by hand until it stops in the fitting. It should spin easily. If the nut is tight, then it is not on the thread. You need to try to unscrew and re-tighten the nut;
Take 2 adjustable or open-end wrenches. One holds the nut body, the other tightens the nut 2-3 turns;
check the assembled system for leaks.

Photo: checking for leaks

Important! Do not use excessive force when tightening the fitting. If a leak appears at the connection point, you need to carefully tighten the fitting nut.

Video: installation using threaded (collet) fittings

Installation of a press fitting on a metal-plastic pipe

Necessary toolfor installation of press fitting:

automatic or manual press jaws;

Photo: press jaws

scissors for cutting metal-plastic pipes or a hacksaw;

Photo: fine sanding paper

special development and calibration to give the pipe the correct rounded shape.

Installation of a press fitting on a pipe:

the pipe is straightened within the cut area;
the location of the incision is outlined;
the pipe is cut with scissors or sawn with a hacksaw at a right angle;

Photo: cropping

With inside The end of the cut pipe is chamfered and burred using a reamer and sandpaper;

Photo: cleaning

using a special calibration tool, the ovality of the pipe that occurs during its cutting is eliminated;

Photo: calibration

a special crimp coupling is put on the pipe;
a special insulating gasket is placed on the fitting fitting to protect against electrical corrosion;

Photo: installation of a press fitting

the fitting fitting is carefully inserted into the pipe and crimped with press pliers;

Photo: crimping

with correct crimping, two uniform rings should appear on the fitting coupling;
For some manufacturers, the coupling of the press fitting is initially permanently fixed to the fitting, so after preparing the pipe at the connection point, the pipe is immediately seated on the fitting.

The correct fit of the pipe on the fitting is controlled through the hole in the coupling and the coupling is crimped.

Important! It is allowed to crimp the connection only once using press pliers. Repeated crimping is strictly prohibited!

Video: installation using press fittings

Installation rules

When performing installation work, it is important to observe the following rules:

Before installation, it is recommended to store pipes indoors, no closer than 1 meter to heating devices. Storage under a canopy is acceptable;
conduct installation work at a temperature not lower than +10ºС;
do not unload rolls of pipes by dropping them from a height;
if metal-plastic pipes were transported at low temperatures, they must be kept indoors for 24 hours;
open laying of metal-plastic pipes is permissible in places protected from mechanical and thermal influences, and exposure to ultraviolet radiation;
Before pipe laying work begins, all fire and welding work must be completed;
When laying open metal-plastic pipes, their laying is allowed only after all finishing works indoors;
When marking, it is unacceptable to use sharp objects;
It is unacceptable to twist the pipes during installation or allow excessive bending;
pipe bending can be done manually;

In this case, the bending radius should not exceed 5 pipe diameters. If you need a larger bend, you must use a special tool for bending metal-plastic pipes.

Metal-plastic pipes are very flexible, so they must be secured. When laying open metal-plastic pipes, special fastening clips are used. When laying horizontally, pipes are fixed every 0.5 meters, and when laying vertically - every 1 meter;
all pipeline fittings must be secured in such a way as to avoid transfer of load to the pipes;
If it is necessary to pass a pipe through a wall or other structure, special sleeves must be used.

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Application

The scope of application is very wide:

hot and cold water supply systems;
installation of floor and wall radiator-free heating (“warm floors” and “warm walls”);
radiator heating systems, with a circulating coolant temperature not exceeding 95 degrees;
irrigation systems;
heating systems for open areas;
soil heating systems in greenhouses, greenhouses, greenhouses;
piping of thermal curtains and water heaters at a circulating coolant temperature of no higher than 95 degrees;
installation of fuel lines and industrial pipelines for transportation of non-food and food liquids;

Installation of water supply

Metal-plastic pipes great option for installing a hot and cold system or in an apartment.

When choosing pipes for installing water supply systems, it is necessary to take into account the operating pressure of the system and temperature (when installing hot water supply systems).

Installation of a water supply system from metal-plastic pipes is carried out in the following order:

is being developed circuit diagram plumbing, on the basis of which an installation diagram is drawn with the distribution of pipes in the room. It is recommended to design a water supply system with a minimum number of connectors;

Photo: installation of water supply from metal-plastic pipes

it is clear from the wiring diagram required length water pipes, the required number of fittings of various types;
The installation diagram shows where the pipes will be secured. The required number of fasteners is calculated. Special clips (plastic locks) are used for fastening;
determined by the type of fittings. If you plan to assemble a water supply system with your own hands and there is no opportunity to buy or rent press pliers for installing press fittings, then we choose compression fitting, for installation it is enough to have a couple of wrenches the right size;

Fittings are the weakest link in plumbing system, so you shouldn’t skimp on fittings and buy the cheapest models.

The pipeline is installed according to the diagram (fastening clips are installed in the designated places, pipes are separated, fittings are mounted);
During the installation process, metal-plastic pipes are bent. Bending of metal-plastic pipes is done manually or using a special spring, which is inserted inside the pipe;

Photo: bending of metal-plastic pipes

Important! During the bending process, it is necessary to observe the maximum permissible bending radii of metal-plastic pipes, exceeding which can lead to damage to the integrity of the pipe.

After installation is completed, the system is tested for leaks, and any leaks identified are eliminated.

Installation of heating pipes

Today, metal-plastic pipes are increasingly used in installation various systems heating.

Installation hidden systems heating is carried out using exclusively press fittings.

During installation open systems For heating, it is permissible to use threaded connectors.

Photo: installation of metal-plastic pipes for heating

When installing heating systems, the following recommendations must be taken into account:

Heating pipes should be fastened in increments of no more than 0.5 m. With a larger increment, the pipes may sag between the fasteners, which can impair the circulation of the coolant in the system;
pipes must be designed for a temperature of 95º C and a working pressure of 6.6 atmospheres;
When choosing pipes, you must pay attention to the availability of quality certificates.

Installation of heated floors

Today, metal-plastic pipes are the most affordable and economical option for installing underfloor heating systems. They bend easily, hold their shape well, are easy to install and operate, and last a long time.

Photo: heated floor diagram

The installation of a heated floor system is carried out using press fittings, so to perform pressure testing of the system you need to find press pliers or invite specialists.

When installing a heated floor system, pipes are laid in a snake, meander or spiral. The total length of one loop should not exceed 100 meters.

Photo: laying heated floor pipes with a spiral and snake

Photo: spiral snake

If the length is long, there will be ineffective heat transfer. When laying loops, ensure the distance between them.

Pipe consumption rate for installing heated floors: 7 linear meters per square meter premises.