The piping system can be assembled using Various types connecting fittings. The choice of this or that solution is not always obvious, because each type of fittings has its own advantages and disadvantages.

Compression fittings

Crimp fittings are also called compression fittings and collet fittings due to the way the crimp connection works. Read more about compression fittings. .

Compression Fittings Advantages:

• Ease of installation. Special skills and "golden hands" are not required. Can be mounted in hard-to-reach places.
• An affordable tool. Installation with common open-end wrenches, no special expensive tools are required.
• Collapsible connection. If necessary, the connection can be easily disassembled using open-end wrenches.
• Reusable. Push-in fittings for metal plastic pipes can be reused after disassembling the connection. It is only necessary to replace the deformed, during installation, split collet ring.

Disadvantages of compression fittings:

• Low installation speed. The low manufacturability of the process leads to a relatively long installation of compression fittings.
• Narrowing of the flow area... This results in a loss of pressure in the system due to the high local pressure drop in the compression fittings.
• You cannot monolith. Compression fittings are only suitable for open wiring, because they require periodic inspection and preventive tightening. Free access must be ensured.

Radial Press Fittings with Press Sleeve Crimp

Radial press fittings were introduced later than compression fittings, but quickly became very popular among professional fitters. ...

Advantages of radial press fittings:

• You can monolith. The high reliability of the radial press connection allows the use of radial press fittings for the installation of underfloor heating systems, concealed installation v building structures(walls, floors)
• Versatility. Pipes and fittings can be used different manufacturers. Selection and replacement table for radial press fittings taking into account the crimp profile.
• Profitability. The complete system is cheaper than other types of fittings

Disadvantages of radial press fittings:

• Special tool required... When installing radial press fittings, it is necessary to use a professional expensive press tool.
• Single use. When dismantling the connection point, the press fittings are removed together with the pipe.
• Narrowing of the flow area... This results in a loss of pressure in the system due to the high local pressure drop in the radial press fittings.
• Not suitable for hard-to-reach places.

Slip Sleeve Axial Press Fittings

Axial press connections were developed for PEX pipes and were later used for metal-plastic pipes.

Advantages of axial press fittings:

• Connection without O-rings. When pressed axially, the pipe itself becomes a seal. Therefore, the reliability of the connection increases and there is no need to calibrate the pipe with chamfering.
• Reduced narrowing of the flow area. Axial press fittings with a sliding sleeve are distinguished by relatively low pressure losses, which compares favorably with other types of fittings for multilayer pipes (crimping, radial press and push fittings). This allows the use of pipes and fittings with a smaller diameter with the same hydraulic parameters, in comparison with the system on radial press fittings.
• You can monolith. The high reliability of the axial press connection allows the use of axial press fittings for the installation of underfloor heating systems, concealed installation in building structures (walls, floors)
• Reusable. Axial press fittings and push sleeves in brass, bronze and stainless steel are recyclable. The connection can be disassembled by heating with a building hair dryer.

Disadvantages of axial press fittings:

• Expensive special tool required... When installing axial press fittings, two types of special tools must be used: a pipe expander and an axial (push-in) press.
• Not suitable for hard-to-reach places.It should be borne in mind that the tool is difficult to use in hard-to-reach places.

Push fittings / push fittings

Push fittings (push - push, push English.) - This is the last, in time of appearance, type of fittings for metal-plastic pipes. Several generations of these self-locking fittings have been introduced in a relatively short time.

The principle of operation of a push-fitting is to self-fix the pipe inserted into it. During installation, the pipe is pressed into the push fitting, sliding onto the integrated union with O-rings. A spring-loaded inner ring system holds the pipe tightly against the fitting and prevents it from coming out of the fitting. Two EPDM O-rings ensure the required tightness of the connection. The pipe must be calibrated and internally chamfered.

Advantages of push fittings:

• No special tool required. Only a pipe cutter and calibrator is required.
• Ease of installation. Special skills and "golden hands" are not required. You can independently mount a pipeline made of metal-plastic pipes on push-fittings.
• Faster installation. Push fittings allow you to perform a large amount of work in a short time.
• Suitable for hard-to-reach places
• You can monolith. Push fittings are reliable , sufficient for concealed installation in building structures (walls, floors).

Disadvantages of push fittings:

• Narrowing of the flow area... This results in a loss of pressure in the system due to the high local pressure drop in the push fittings.
• High price. These are the most expensive fittings for metal-plastic pipes.

TECEflex is a system polymer pipes with a wide range of applications in internal engineering systems... Brass fittings are certified and approved for piping networks drinking water, heating, gas supply and compressed air... The special design of TECEflex metal-polymer pipes makes them suitable for universal application... An exception is the gas pipe, for which outer layer yellow color. This is why TECEflex is a truly versatile piping system.

Versatile piping system for all indoor engineering applications

• Can be used in drinking water, heating and compressed air pipelines - "5 systems - one fitting"
• O-ringless connection technology
• Pipes and fittings with practically the same internal cross-section
• Thick-walled, break-resistant metal-polymer pipes with diameters of 14-63 mm
• Installation error-resistant technology
• Simple tools
• Wide range of brass fittings with diameters 14-63 mm
• PPSU fittings (polyphenylsulfone) with diameters of 16 and 20 mm as an inexpensive alternative
• Resilient to errors and reliable
• High temperature resistance and compressive strength

Download documents:

TECEflex pipes are permanently connected with fittings using the method axial pressing... Only the pipe material is used as a seal. No other means, such as O-rings or sealing tape, are required. The sealing technology without O-rings is extremely resistant to installation errors and is particularly hygienic.

TECEflex offers a wide range of brass fittings. Universal brass fittings used for piping networks of drinking water, heating, gas supply and compressed air. The fittings are made of special corrosion-resistant brass (low dezincification rate) recognized in Europe and recommended by DVGW. In accordance with the current drinking water directives, it is suitable for all water qualities.

The DVGW approval confirms the hygienic and biological suitability of the TECEflex for drinking water and long term service - at least 50 years. The strong point there is also a technology for axial pressing without O-rings. There are no cavities in the joints, and water stagnation, which is important from a hygienic point of view, does not occur anywhere. The materials used for the fittings are approved throughout Europe. Thanks to the use of corrosion-resistant (CR) brass, TECEflex fittings do not require additional protective layers with complex application technology. The TECEflex system is suitable for all drinking water qualities.

TECEflex metal-polymer pipes are equally suitable for drinking water, heating, radiant heating and compressed air pipelines. The gas supply pipe differs only in its yellow... Due to its special design, the universal pipe has a high safety margin, retains a circular cross-section when bent and does not form burrs when cut. Inner tube wetted made of DVGW registered PE-Xc polyethylene.

Up to and including 32 mm diameter, TECEflex connections can be made with hand tools... Most of the joints are performed using only muscle strength. No electricity or batteries needed. The tools are very lightweight and extremely reliable. They don't need regular maintenance. To connect the pipes, you just need to push the press sleeve onto the part of the pipe that covers the fitting - you get a tight connection!

Good day to everyone who reads this article. In it I will briefly talk about axial fittings and pipes for them. Nowadays, they are becoming more and more popular. Especially from developers who use them wherever possible and impossible. I try to start all my articles with definitions and there will be no exceptions.

What is an axial fitting?

Axial fitting - brass or plastic fittings for XLPE pipes with a special slip-on sleeve. The connection of such fittings to pipes is carried out using two special tools:

• Expander mechanical or electrical - carries out expansion polyethylene pipe... After that, it becomes possible to insert the fitting into the pipe.
• Electric or mechanical axial press - this tool pulls the sleeve onto the fitting. This is done using special replaceable lips.

As usual, for a better understanding, take a look at the following pictures:

Electric axial press.

And one more picture:

All of the inventory described above is sold in sets, which include an expander, a press and various attachments for them. In most kits, nozzles start at 14mm and end at 32mm. It looks like this:

Now, to broaden our horizons, let's talk about what cross-linked polyethylene is.

What is XLPE.

Everyone who has held a plastic bag in their hands knows what this material is. It is used for cold water supply, but such material is not suitable for heating and hot water supply. To increase the strength of such pipes, molecular cross-linking of polymer chains is used. This allows you to get good characteristics material strength with relatively thin pipe walls (pipes with SDR 7.4 are usually used for heating). There are several types of polyethylene crosslinking:

• PEX-a is a chemical crosslinking method using the addition of peroxide.
• PEX-b is a silane addition assisted chemical crosslinking method.
• PEX-c is a radiation crosslinking method.
• PE-RT - crosslinking by adding copolymer during production

In addition, such pipes are produced with an EVOH anti-diffusion layer. Such a pipe will already be five-layer like metal-plastic. To make it clear, look at the picture below:

I must say that if you cut such a pipe and look at its end, then no layers will be visible. But this does not mean that they are not there and you were deceived, they just are all transparent and smoothly merge into one another.

Now I will give you specifications XLPE pipes:

Let me remind you that the higher the temperature, the shorter the service life of such pipelines. I say this specifically for those who want to connect such a pipe directly to solid fuel boiler... Now let's talk about where axial fittings can be used. Yes, and I almost forgot! If you are going to make warm floors using such a pipe, then it is very desirable that the length of the circuit does not exceed 100 meters. Otherwise, due to the large circulation along the circuit, there will be no.

Where can axial fittings and pipes be used?

Axial fittings, as mentioned above, are designed to connect sections of XLPE pipes. According to them, they can be used in heating systems of private and apartment buildings, in water supply systems and for the transportation of non-aggressive liquids (for example, refrigerants).

Heating systems in apartment buildings use pipes with a thicker wall than in private houses and cottages. And for you can use pipes with a wall of 2.0 mm. The fittings themselves can be made of either brass or special plastic - PPSU. This is my personal opinion, but brass seems to me more reliable. I repeat, mine is mine and not necessarily correct.

Now let's discuss the features of the installation of this material.

Installation of PE-RT and PEX pipes with axial fittings.

The main installation method for these types of pipes is hidden. That is, pipes are laid inside walls or floors. If we are not talking about water warm floors, then the pipe is laid in a corrugation, which protects it from mechanical and other damage. As for them, a separate article was written about them, which I recommend reading. And in order not to be unfounded, I suggest watching a video on the installation of PEX or PE-RT pipes with axial fittings:

I can say that such a method of installation is within the power of any person and there are no special wisdom and tricks here. The prices for the instrument, of course, bite, but now it can be easily rented at the box office or from the sellers themselves.

Results of the article.

As a result, we can say that the use of cross-linked polyethylene for distributing heating or plumbing around the house is an option worthy of your attention. The pipe itself will be much cheaper than the metal-plastic pipe and at the same time will have almost all of its advantages. The only exception here will probably be that it does not keep the shape of the bend as well as PEX-Al-PEX. PE-RT or PEX, in my opinion, are the most profitable solution for water-heated floors and heating installation using radial distribution. If you take water supply, then only polypropylene pipes... There is no comrade for taste and color. That's all, I'm waiting for your questions in the comments.