The modern plumbing market provides many pipes from various materials, which are used for laying sewers, water pipes and other similar systems. Pipes made of different materials differ not only in their characteristics, but also in the way they are connected to each other.
Plastic pipes have several similar connection methods, but they all differ in their strength and ease of execution. In this article, we will analyze in detail all types of polyethylene pipe connections, as well as their advantages and disadvantages.
Introduction to the material
To begin with, it is worth disassembling the two main properties of polyethylene, from which pipes are made. Its first property is plasticity. Turning to GOST, you will see that the elongation coefficient of the material at break is 250%, but in reality this figure can reach 500-600%.
Such a high rate of plasticity is not always a plus. Thin polyethylene pipes won't survive high pressure, and the threads cut on them for connection will completely make them inoperable, so it will not work to connect them with a thread.
The second property of polyethylene is fusibility. It allows you to weld pipes, because they begin to melt at a temperature of only 105-110 ° C. Here you can also find a significant drawback of these pipes - a low limit operating temperature, because the pipes soften at a temperature of 80 ° C, so it is impossible to use them for transporting hot liquids.
Having learned these properties, we can conclude that compression fittings for polyethylene pipes, as well as welding with a soldering iron - the best solution during assembly sewer systems. Next, we suggest that you familiarize yourself with all the connection methods in detail.
Butt welding
Despite the fact that fittings for PE pipes make it possible to achieve a reliable connection, it is not always advisable to use them. So, for example, pipes of wide diameter are connected strictly by butt welding, because large fittings cannot be quickly attached to the pipe after desoldering.
When assembling lines from pipes of large diameter, specialists use heating devices that melt the ends of two pipes, after which they allow them to cool down, turning them into a single whole. The result is reliable connection, the strength of which is equal to 90% of the strength of the pipe itself, which is quite enough for highways with walls several centimeters thick.
Connection with welded fittings
AT this case fittings are used for welding polyethylene pipes, which differ from similar products for polypropylene pipes only with your material.
The connection is made according to the following instructions:
- Cut the pipe so that the resulting end is perpendicular to the axis;
- Chamfer the outside of the pipe and inside the fitting so that the connection is made without various irregularities;
- Choose a soldering iron nozzle that is suitable for the diameter;
- Select correct temperature heating the nozzle, bearing in mind that the melting point of polyethylene is lower than that of polypropylene by approximately 50°C;
- Next, put polyethylene pipes and fittings for water supply on the soldering iron;
- Now you can insert the pipe into the fitting, however, you must not turn the pipe, otherwise this will lead to the formation of peculiar waves that will reduce the strength of the connection, as well as create a slight resistance to the flow of water.
Electrofusion connections
This method of connection is also based on the weld fittings described above, however, here you do not need a soldering iron. Such a connection of polyethylene pipes is made with fittings with a built-in metal spiral, which has a high resistance to electric current. Under tension, this spiral heats up strongly, melting the fitting.
Work should be carried out according to the following instructions:
- Assemble all planned pipeline;
- Connect step down transformer to electrical network or use a car battery;
- Connect terminals to coupling(details: "");
- Wait for the time required for it to melt (may be indicated on the fitting or instructions for it), after which, do this work with all other electric couplings.
Compression fittings
Such fittings for polyethylene pipes completely solve the above problem. The compression fitting is a simple but independent system that consists of the following components:
- plastic case;
- Sealing rubber bands;
- Tightening nuts.
Assembling such a system is quite simple:
- Insert the pipe into the fitting, after lubricating it with soapy water;
- Tighten the tightening nut securely, which will press the sealing rubber.
There are many advantages to such a connection, but we will highlight two main ones. The first advantage is the ability to disassemble and reassemble the finished pipeline system. This possibility is especially relevant when using a boiler or a cleaning filter. The second plus of compression fittings is the ability to assemble the system without any auxiliary tools.
There are also some obvious downsides. For example, such connection fittings for polyethylene pipes have a short service life, because the tightness of the connection depends entirely on the state of the sealing gum, which may lose its elasticity over time.
Conclusion
It is impossible to make a final choice between all the above methods of connecting polyethylene pipes, because each of them has important advantages, for example, welding is high reliability, and compression connections- this is ease of maintenance, so you have to make the final choice yourself.
Today plastic pipes confidently gaining popularity, and for them quality installation not to do without special connecting devices. With the help of compression fittings, installation of systems from HDPE, PE is carried out.
Compression fittings for polyethylene pipes guarantee complete tightness at the junction of the connected sections of the PE system without the use of welding machine.
This part is able to connect the elements of the pipeline, in which there are branches, turns, pipes of various section sizes. They also help to quickly dismantle a certain part of the structure when it fails or breaks.
These connecting elements are produced immediately ready for installation. No need pre-training in addition to chamfering.
general information
Compression fitting for installation of polyethylene and HDPE pipelines consists of:
- clamp cover;
- rubber sealing ring;
- crimp ring;
- bushings for pressing.
Crimp ring and rubber compressor, which are inside it, are the main connecting elements of two pipes with each other. It is them simple design allows for quick installation.
BUT a large number of assembly and disassembly does not affect the performance of the fitting.
Installation or repair work of the pipeline with the help of such connecting elements is so simple that there is no need to seek help from professionals.
It is possible to do all the work yourself. Any high-quality plastic compression fittings for connecting polyethylene, HDPE pipes must have conclusions about their hygienic safety, which guarantees the possibility of using them in water supply systems for transporting drinking water.
Features of the connecting element
Connecting elements for HDPE pipes and for installation polyethylene pipelines These are products of high strength and the possibility of a long service life.
They have the most various sizes sections from 1.6 to 11 cm, which makes it possible to equally well combine the constituent elements of systems with different section.
The polymer, thanks to which compression fittings are produced for connecting polyethylene, HDPE pipes, allows products to not react at all to any chemical environment upon contact.
They connect equally effectively and have no contraindications for contact with drinking water and other food liquids.
Data is used for low-rise buildings and with a wire. Fittings are used wherever their connection is required.
They, at a temperature regime of about +20 degrees, connecting HDPE pipes with a cross section of up to 63 mm, withstand internal pressure up to 16 bar.
When connected large diameters it is desirable that the pressure does not exceed 10 bar.
Storage and application
Video 1.
The storage of fittings does not require any specific conditions, the main thing is to protect them from UV rays, but if we talk about polypropylene products, which are used more and more often, then they Sun rays do no harm.
Negative temperatures will not affect the quality of products in any way, but when stored in a heated room, place plastic compression fittings no closer than a meter to any heating device.
And forms, threaded on the inside or outside details.
Each of these elements can be used both for the installation and repair of plumbing systems using durable polyethylene grades PE80 and PE100, which are used both for transportation drinking water, and liquids for technical purposes.
Polyethylene components are often used when creating an automatic irrigation system on a plot or flower bed.
Installation instructions
Video 2.
Using, plastic fittings for PE pipes or polyethylene systems it is worth following all the recommendations of the manufacturers regarding their installation and use, as well as adhere to the instructions for use that were issued at the factory.
If the pipes comply with all standards, then their connection should not cause problematic consequences.
Fittings with a diameter of 16-50 mm are mounted without the use of any plumbing tool, while for connecting pipes large diameter use a chain wrench.
In order to connect correctly, it is recommended to follow the following instructions:
- using any sawing tool, we cut the pipes at a right angle to the desired size;
- joints should be cleaned of burrs and sawdust at the same time slightly rounding them. The joint must be completely clean and free from visible cracks or irregularities;
- screw of blue color is removed from the fitting and put on the pipe, and the clamping ring white color set in such a way that its thick part looks in the direction of the tail of the pipe;
- the pipe is inserted into the connecting structure until it stops, it is also done with the ring. Tighten the blue nut initially with bare hands and then tighten it harder using a special tool.
Benefits of using them
Plastic compression fittings guarantee a tight connection of pipelines made of PE, PP and HDPE components, thanks to a special sealing system.
They do not need constant checking and tightening, therefore they can be used when installing an underground water supply system or what will subsequently be walled up in concrete.
Plastic compression fittings polyethylene HDPE maintain working pressure in system to 16 atmospheres. They are easy to install, and the quality of the connection is not affected by any additional preparation.
Technological features make it possible for short time establish a connection and reduce installation costs. The connection does not give in to corrosion, is hygienic and durable, moreover, it perfectly connects plastic products of different diameters.
These connectors are complete. This suggests that any element of the product can be replaced using spare parts of the same product group.
It is worth considering that the ring intended for axial clamping is made of durable and at the same time fragile polyamide, and if it breaks, then the fitting can no longer be used and must be disposed of.
Video 3.
If we talk about the seal, it is made of rubber-like plasticized polyethylene. The main body of the fitting is made of polypropylene.
In order for the product, with a thread embedded in the inner diameter, to be as strong as possible, in some of their varieties an outer steel clip is added.
They are compatible with every PE pipe made from LDPE (40, 80, 100) and are manufactured to suit all regulatory requirements.
In practice, many professional workers involved in the installation and repair work in plumbing systems, convinced of the reliability of compression plastic connecting elements, which are integral parts in any plumbing construction polyethylene or HDPE pipelines.
In addition to the fact that compression fittings for polyethylene pipes do not react to sharp temperature fluctuations, to chemically active environments, they can work without interruption for half a century.
In the article we will try to systematize all the ways of connecting polyethylene pipes.
As part of the article, we will also touch on connections different types welding, and compression fittings for polyethylene pipes.
Material Features
What do we know about polyethylene pipes?
- They are plastic. The elongation at break of polyethylene lies between 500 and 600 percent; for finished products in GOST, a more modest value is fixed: 250%.
What does this mean in terms of connecting several pipes into a long water supply? Only one thing: on a relatively thin one, it makes no sense to cut a thread. She still can't handle a lot of pressure.
Tip: However, threaded polyethylene pipes are used in some applications.
In particular, for the use of HDPE pipes as casing when drilling wells for water.
Here are threaded pipes - perfect material. They are connected without thickening and irregularities, which is very important in this case.
Such a connection is not suitable for a water supply system, but just right for a well
- They are fusible. The melting temperature of polyethylene lies in the range of 105-135 C, depending on the polymerization conditions, while the material begins to soften already at 80 C.
This, in turn, means two things: you cannot put polyethylene pipes on hot water; they can be joined by cheap and simple low-temperature welding.
Hence, there are two main ways to connect pipes: compression fittings for polyethylene pipes and welded joints different types.
Connection methods
Butt welding
It’s worth mentioning right away: polyethylene pipes are not always connected using fittings. Pipes of large diameter are generally welded strictly end-to-end. In fact, fittings with a diameter of about a meter and heated on a soldering iron and put on a pipe in a few seconds until the plastic has frozen is a big problem.
For the installation of large diameter lines, special heating devices are used, which, after centering, melt the ends of the pipe and allow them to cool as a whole.
The strength of such a connection reaches 90% of the strength of a monolithic pipe; with a wall thickness of the main pipes of several centimeters, this is sufficient in excess.
Weld Fittings
Fittings for polyethylene pipes for welding neither externally nor structurally differ in any way from the same ones.
The principle of installation is exactly the same:
- Preparing the pipe and fitting. The pipe is cut strictly at right angles to its axis; With outer side pipes and inside fittings are chamfered.
This is necessary so that the pipe enters the fitting without bumps and burrs. - The nozzle of the soldering iron is selected according to the diameter of the pipe. After it is warmed up, a fitting is put on its narrow side for a few seconds, and a pipe is inserted into the wide one.
The melted surfaces are combined and fixed until the polyethylene hardens. You can move on to the next connection.
Tip: when choosing a temperature, do not forget that polyethylene melts at a temperature of fifty degrees less than polypropylene.
Also, never twist the pipe while inserting it into the fitting. It will gather in waves, which will sharply weaken the connection.
Electrofusion connections
Before us special case fittings for welding. The only difference is that they do not need a soldering iron: a coil of metal wire with high resistance is part of the fitting itself.
This drastically simplifies installation, making it extremely simple and fast:
- We fully assemble the plumbing in the configuration we need;
- We fix all its main elements with plastic latches or in any other way;
- And then we just go along the mounted water supply with a simple transformer or even a car battery with a couple of wires. Each fitting is energized for a short time. At the same time, it is fused with the pipe into a single whole.
Polyethylene pipes and fittings connected by welding have one drawback: all connections are non-separable. For the sake of any change in the configuration of the water supply, it will simply have to be cut and welded again using a new set of pipes and fittings.
This problem is completely devoid of the following installation method.
Compression fittings
Polyethylene pipes and fittings are connected in this case in much the same way as in the case of metal-plastic. However, the use of a split ring that compresses the pipe on the fitting nipple is not applicable here.
Soft polyethylene will simply warp or tear at the point where the most force is applied.
That is why compression fittings for polyethylene are actually a fitting body, a union nut and a rubber seal located between them and the pipe. The nut is screwed onto the thread of the fitting and compresses the rubber, sealing the connection.
The advantages of this method are obvious: the connection can be mounted without any tool, with bare hands. Of course, with a small pipe diameter: after all, compression fittings are available up to a size of 110 millimeters.
Unfortunately, the quality of the connection is very dependent on the reliability and durability of the rubber seal. Low-grade rubber is not applicable here: as soon as it loses elasticity, the connection will begin to flow.
In addition, resistance to external mechanical influences also leaves much to be desired. Just tripping on the pipe, it is not a problem to pull it out of the connection. AT apartment building this is fraught with not the most pleasant date with the neighbors below.
Conclusion
Polyethylene pipes and fittings are undoubtedly excellent choice for cold water pipes. In terms of reliability and durability, welded joints are the leader, in terms of ease of maintenance, compression fittings. The choice is yours. Good luck!
The pipeline made of polyethylene has increasingly become used in modern repair work. In new houses, as well as during major repairs, old ones are almost impossible to meet welded pipes of steel. Even when installing heating, they are increasingly resorting to the use metal-plastic structures. This pipeline is much cheaper to operate, more durable and is not affected by such a phenomenon as foundation settlement, which is why in old buildings the pipeline is regularly depressurized to the places of its weak connection.
To install a new generation of pipeline structures, fittings for polyethylene pipes are used. With their help, you can mount any configuration of the pipe network, as well as provide the necessary branches and bends.
Fittings that connect pipes of the same width are called straight, and those products that are designed to connect communications of different diameters are called transitional.
The connection of pipes using fittings is distributed by wide assortment samples on the market.
Fittings can:
- Provide pipeline bends at various angles.
- Provide connectivity in multiple directions.
- Work to increase or decrease the width of the pipeline in the right places.
Only fittings for pipes made of polyethylene for welding differ from all other types of products in their functionality. This auxiliary part is installed on the pipe, and then the junction is heated with a special soldering iron. In terms of strength, this type of connection is not inferior to solid casting. The only disadvantage of this design is that once the system has been dismantled or reconfigured, they cannot be reused.
Compression fittings
This type of fitting for connecting polyethylene pipes is optimal because no special skills or tools are required for installation. To install them, only the muscular strength of the hands is required. Compression fittings are a plastic housing with rubber gaskets and two clamp nuts. Nuts are screwed onto the threaded ends of the pipes, and a well-tight rubber gasket prevents liquid from seeping through at the junction. The nut is usually covered with hooks on the outside so that it does not slip out even from wet hands when twisting.
The pipeline with compression fittings lends itself perfectly to dismantling, so it is very convenient to use, for example, on suburban area for surface water supply. For the winter, it can be easily disassembled and folded into a specially designated room.
In addition to compression fittings, other types are used to fasten pipes. Consider them and compare with the first option.
Electrofusion fittings
This type of pipe fastening can be called the most exotic. At the same time, it provides one of the most reliable and durable connections. Electrofusion fittings for polyethylene pipes are a plastic case, inside of which there are copper heat-energy carriers that have an outlet for a special electric heater. Electricity, supplied to the outlet, provides a gradual heating of the fitting, due to which a continuous seam is obtained.
The electrowelded connection is very durable and has many undeniable advantages. For example, a pipeline connected using such fittings can be dismantled and reused. To do this, you need to re-heat the fasteners and disconnect the pipes. The connection is very reliable, it is not inferior in strength to a one-piece cast system. It is very easy and quick to install a pipeline using electrofusion fittings, so this option is perfect for systems with large quantity branches and bends. You can install this design where it is impossible to reach with a soldering iron or hands. Repair of the electric welding system is carried out quickly without making changes to the general scheme. The welding process can be carried out in automatic mode, and the fittings are recognized by the barcode indicated on the body.
Of course, this type of fitting is very convenient to use, but there is also dark side medals. The disadvantage of such systems is their cost. High price due to the use of expensive materials in the design of the fitting. On the other hand, fixing the pipeline is not something worth saving on, so the choice is yours.
Press fittings
Press fittings for polyethylene pipes are very convenient to use because they require a minimum amount of equipment to install. Such a fitting is a body with several gaskets, as well as two sleeves, which are pressed onto the ends of the connected parts of the pipeline.
Most often, only straight options are used as press fittings.
Pressing is carried out using special press tongs that fit the sleeves with great effort without the possibility of leakage. These fittings have an antistatic ring, which does not allow the charge to accumulate due to the potential difference between the two types of material.
Press fittings have many distinctive qualities. For example, their installation does not require electricity and great physical effort, since the fasteners are installed using the press tongs lever. In addition, press fittings provide high reliability of the connection, since the joints are made of metal. It is also possible to dismantle the pipeline using press tongs, but to re-install the system, each fitting must be numbered so that it is re-installed in its original place.
Brass fittings
Brass is one of the softest copper alloys and has a number of advantages over steel. Typically, brass fittings for polyethylene pipes are installed on threaded connections. Brass can also be used in the production of press fittings. Copper alloy fittings have a large margin of safety, exceeding that of plastic products. Brass fittings are usually produced in various options, which allows them to be used for the installation of non-traditional systems.
Brass fittings have their advantages. They can be used to extend pipes. If you use FUM tape, the connections are quite tight. Also, brass is a flexible and pliable material, which makes it possible to install a polyethylene pipeline with tension. In some situations, this output is the only one. It should be noted that brass is absolutely harmless and does not burn. When using it, it is instantly covered with a layer of patina, which is inert to both cold and cold. hot water. In addition, the brass pipeline can be cleaned with acid, this will not affect its properties in any way, unlike steel systems. When vibrations occur, brass joints are not destroyed due to the flexibility of the material.
Crimp fitting. What's this?
Compression fittings for pipes made of polyethylene work using the technology of tightening the ring of flexible material with a slot when tightening the compression nuts. Basically, compression fittings are made of brass or plastic. They do not require installation. professional equipment, during the installation process, you need to use the muscular strength of the hands and a pair of wrenches.
There is another kind compression fittings- collet structures. The crimping principle in this system is similar to that which holds the lead in collet pencils.
Fittings with a crimp system are distinguished by the fact that they allow you to hide the error in the diameter of the connected pipes, thereby eliminating the need to calibrate the structure. These fasteners are perfect for eliminating a pipeline breakthrough, regardless of what the pipes were made of. The main thing is that at least a small chamfer is removed from the surface.
Preparation and installation of fittings
Connection process polyethylene elements distinguished by its lightness and speed. In addition, such systems are durable, reliable and economical. This is what provoked a rapid growth in sales of products made from this material. For high-quality installation of the structure, you need to use the instructions drawn up by professionals. Installation work for connecting polyethylene fittings and pipes require special training:
- The amount of material required must be calculated in advance; for this, the total length of the system, the number of angles and drops are measured.
- Turn off the water supply before installing fittings and polyethylene fittings.
- If the room is installed heating system, then start his work from the boiler.
Welding of polyethylene fittings with pipes occurs according to the following principle:
- After cutting the pipes required sizes you need to remove the chamfer from the edges.
- Insert the PE fitting and the prepared edge into the nozzle at the same time.
- Heat the parts for a couple of seconds, then remove them from the nozzles and fasten.
For a long time, the only materials used in sewer systems were steel and cast iron. The advantages of these materials include a long service life and strength, and the disadvantages are a complex labor-intensive installation, high cost and deterioration in the quality of the transported substance.
In the past few years, there has been active work for the replacement of old materials of sewer systems. Manufacturers tried to find the material that would include all the advantages of cast iron and steel and exclude their disadvantages. Not so long ago, this substance was found, it is polyethylene, and now both pipes and fittings are made from it. Initially plastic products did not have such high level strength, they quickly collapsed and crumbled under the influence of water and sun, but now all these problems are in the past, and now polyethylene pipes, fittings and fittings are the most reliable and inexpensive components of the sewerage system, which are widely trusted by both construction professionals and and ordinary citizens.
When assembling or repairing a water main from polyethylene pipes, in areas of branching, bending and connecting pipes with different diameters, mechanical and welded fittings are applied. They are focused on the requirements of GOST 27077-86, and include the following types products:
- For gasket gas pipes: fittings of thermistor and cast type.
- For water supply: compression (collet, clamp), segment welded and flange type.
- For drainage system: corrugated type.
Design features
By their own functional features fittings are divided into the following types:
- Tees (for joining 3 elements of the pipeline): even for connecting pipes with the same cross section and reductive (transitional) for products with different diameters.
- Elbows (change the direction of the line at a given angle).
- Couplings (for joining pipes in a stationary state).
- Crosses (for education unified system of four products or channel division into 4 branches).
Compression fittings
They are used when installing external water supply (drinking and irrigation purposes) with a diameter of 110 mm or more. The catalog of fittings is represented by couplings (equilateral and transitional) with internal or external thread, elbows, adapters and plugs.
The main structural elements include:
- Body part.
- Cover with nut.
- Sealant.
- Clip of round section.
- Pressing sleeve.
Compression fittings provide crimping with a ferrule and sleeve. The ring prevents breakout during hydraulic shock and vibration.
Positive characteristics:
- Eliminate the need for special tools.
- They give flexible and rigid properties to the fastening.
- Quickly and easily mounted.
- Available in a wide range of parameters and raw materials used.
Cast connections
Molded fittings - complete structures obtained under pressure with further machining. They are used for laying water and gas pipelines. Allow to carry out turns and branchings, to make docking of pipes with different parameters. It is allowed to connect cast clamps with welded clamps.
Butt-welding technology is used to connect to the pipe - the ends are aligned and melted, the formed joints withstand pressure, similar to a PE pipe.
An additional method of docking is the use of welded couplings. Cast fittings have an extended shank for mounting thermistor couplings.
Electrofusion joints
Represented by a series of connecting elements, for the fixation of which the technology of melting the upper part of the contours and the walls of the fittings is used with the help of a heating coil inside the connecting element. They belong to the low price category and used in confined spaces. The limiting pressure range reaches up to 25 atm. Temperature conditions up to 40 gr. The connection to the pipeline is carried out by butt welding.
Segment fittings
They are formed under the influence of HDPE 80 welding. They are used in branched water pipes.
Thermistor connections
Principle of operation: welding equipment is connected to the outputs of copper windings located inside the structures. The passed current heats the winding, the fitting melts, connecting with the pipeline. The disadvantages include the high cost and the need for special welding machines.
Flange clamps
Docking circuits with fittings using flanges contributes to the tightness of the pipeline and prompt assembly / dismantling of the system. It facilitates the technology of connecting different containers, equipment and mobile mechanical elements. Paronite gaskets are used as seals.
Corrugated pipe fittings
When connecting elements of a water main and a non-pressure sewage system, welded corrugated pipe fittings are successfully used. To prevent displacement of the pipe during installation, a special rubber seal is used, located in the inside of the socket.
Fitting diameter
The dimensions of the connecting elements directly depend on the parameters of the pipes, their bandwidth and wall thickness, but you should remember a number of nuances:
Thick products. Marking allows you to find out the outer diameter of structures, without taking into account internal parameters. And thick walls affect the decrease in the parameters of internal patency.
Surface roughness. The internal coating of PE pipes is characterized by high rates smoothness. This helps to speed up the transport of fluid and reduce the level of plaque formed.
Due to the increased wall thickness, the most popular option is a diameter of 20 mm or more. When compared with metal-plastic pipes, then the most requested parameters correspond to the number 16.
Common fittings and pipes made of PP include products with parameters of 20, 25, 32 and 40 mm. The maximum size threshold includes 110 mm, but it is in little demand.
Tip: for plumbing in private construction with optimal amount tapping points topical solution will be pipes with a cross section of 20 mm.
Pipe joining technology
The connection of PE pipes is carried out by 2 methods: welded and detachable. The welding technology consists in the fact that the ends of the circuits are preheated to viscosity, connected and subjected to pressure until they completely merge with respect to each other. After performing welding work in compliance with the temperature and requirements, a strong monolithic seam is obtained. This technology is used for structures with a cross section of 50 mm.
The detachable technique is performed using clamps compression type, made of brass or plastic. The need for constant monitoring of the connection eliminates the possibility of its use in hard-to-reach areas, so it is more often used in residential buildings where a large number of turns and wiring are required. If it is necessary to lay a non-pressure pipeline or gas lines, this technique is the simplest and most economical. The exclusive advantage is that there is no need to use a welding machine, special experience and knowledge. Installation can be done by hand.
Mechanical (split) fittings
Clamp fittings are used for technologically simple and economical affordable creation given configurations of highways of any complexity. For the repair and laying of water pipelines, structures with a diameter of 20-110 mm are used.
This is due to the inability to connect thin-walled structures end-to-end and the high cost of socket and thermistor welding methods.
Structurally, the joints are equipped with clamping parts and replaceable body parts (elbows, triple ramifications, etc.).
- The flare nut is connected to the body by crimping the collet.
- The toothed collet covers the PE contour and pulls it up to the body part.
- The thrust ring transmits the tightening power of the nut to the O-ring.
The products of a number of manufacturers are presented single design from a collet and a thrust ring. The seal in the form of a ring provides reliable sealing of pipes along the outer cross section. The housing is equipped with internal stops that prevent the movement of pipes in the connection. The parameters of the product are indicated on the body part.
Material selection
The body part and the nut are made of PP, the toothed collet is made of solid polymers: POM (polyoxymethylene) or PPO (polyphenylene oxide). The seal is made of durable and flexible NBR rubber.
During the operation of products, with an increase temperature regime a lower pressure is provided, which is due not to the strength characteristics of the joints, but to PE pipes. With an increase in the level of heating, PE becomes softer, pipes can come out of the tee or elbow with insufficient axial force.
The table indicates the working pressure, but in practice a short-term increase is possible.
Standard set of fittings includes:
Solid systems are complemented by tank connections, adapters for metal pipes, adapters and tees. Tank connections are used for quick and reliable connection of the PE circuit to a container (made of plastic or metal) for liquid media.
They are presented in the form of a coupling with an extended thread, a plastic nut and a seal. Sealing is provided not on the thread, but on the surface of the tank.
Adapters for metal pipes provide easy connection of polymer threads or PE contours. Adapters are available only for pipes with a cross section of 15-28 mm.
brass connections
In terms of quality, they are comparable to PP fittings and have a similar device. Key advantage the possibility of connecting with a "bad" metal thread and reusable use.
The toothed collet is made of metal or plastic. The first option is used for clamping PE and PP structures. For installation, a conventional wrench. In terms of cost, polymer fittings win 1.5-2 rubles.
saddles
They often replace tees when necessary to branch out the water line. This makes it faster and more economical. But the contour following the saddle outlet will have smaller parameters. For uniform flow division, a tee is required.
Saddle outlets are presented in the form of polymer clamps with a side outlet ( threaded connection inside the pipe). A coupling with an external thread or a shut-off valve is screwed into the outlet. Branches correspond to parameters of standard pipelines: 25 - 315 mm. If the threaded outlet is equipped with a steel ring that prevents rupture if incorrectly installed, it belongs to the series of reinforced fittings.
Threaded connection adapters
The product range includes:
This includes transitions from external to internal threads and vice versa. "Bushi", "futorki" and "cuttlefish" provide a transition between threads of different sections and thread. They turn the clamping threaded socket into an elbow. However, a large number of adapters can harm the system: optimal solution there will be a line of 1-2 threaded connections.
Fitting cost
Fitting prices have little effect on the overall price of a pipeline. For example, a threaded coupling d = 25-32 mm has a cost similar to 1.5-2 m of pipeline. A similar coupling Ø 6.3 cm is comparable in cost to a 2.5-3 m pipe, and Ø 11 cm is comparable to a 4 m pipe. Fittings with such parameters are more expensive than thermistor clamps.
Video
