Tool for stripping reinforced polypropylene pipes. Stripping for polypropylene pipes: methods and tools. The principle of operation of the trimmer for metal pipes

Metal in household communications is gradually being replaced various materials from polymers. The properties of polypropylene are especially attractive to the consumer, allowing it to be used for all household communications.

Polypropylene is resistant to corrosion and deposits, does not change properties under the influence of aggressive chemicals. Water transported through systems made of this material does not lose its properties. The large throughput is also important, due to the completely smooth inner surface.

Types of reinforcement

Non-reinforced polypropylene is characterized by low thermal conductivity and high temperature resistance. Over time, it changes shape. This property is called fluidity, which requires the installation of fasteners every 50 cm of the pipeline.

Fluidity is especially pronounced at elevated temperatures of the internal environment. The main purpose of reinforcement is to reduce this quality. After reinforcement, the polypropylene material becomes more rigid, sags less when laid in a horizontal position, which makes the system more stable.

The aluminum tape reduces the coefficient of linear expansion to a level that is comparable to that of metal products. In addition, aluminum contributes to a decrease in oxygen conductivity. Even better quality when reinforced with fiberglass. This material makes installation easier than aluminum tape as there is no need for stripping prior to soldering. It is also important that products with fiberglass are cheaper than products with aluminum tape.

For reinforcement, solid or perforated aluminum foil can be used. It can be located near the outer shell or in the middle of the wall. The solid foil is bonded to the polypropylene with hot melt adhesive. The use of low-quality raw materials in the production entails delamination during operation.

A similar phenomenon is impossible if perforated aluminum is used for reinforcement. Holes in the foil make it possible to create a monolithic connection between plastic and aluminum without using glue.

When choosing polypropylene products, it should be borne in mind that some manufacturers, in order to reduce costs, use low-quality raw materials and make pipes have too thin walls. This entails delamination and instability to internal pressure. By external signs, it is quite difficult to distinguish a high-quality product from a low-quality one. You need to purchase material with the thickest walls (that is, one with a heavier running meter).

Recently, polypropylene pipes reinforced with fiberglass have appeared on the market. Sometimes they are called fiberglass. If a product reinforced with aluminum, in fact, consists of five layers, then the use of fiberglass makes it possible to obtain a material with a monolithic structure, since the middle layer is the same polypropylene, but mixed with fiberglass. All three layers are not glued, but welded, which completely eliminates delamination.

However, fiberglass-reinforced products still have one drawback - their linear expansion is 6% greater than when using aluminum. Why do you need to clean up polypropylene pipes before soldering. Some reinforced products must be stripped before soldering to remove the outer layer of polypropylene and aluminum foil, which prevents a strong connection with the fitting.

Stripping reinforced polypropylene pipes is always required when aluminum is used for reinforcement, and regardless of where the foil is located. The only difference is the tool used. If aluminum is located in the middle of the wall, a trimmer is used. Fiberglass reinforced material does not require stripping, since it is all made of polypropylene.

Stripping tool

The cleaning tool for polypropylene pipes makes it possible to work with products with a diameter of 16 to 110 mm. For diameters up to 63 mm, double-sided couplings are produced, which allows you to clean the ends with two different diameters if the aluminum layer is located at the outer surface. The knives of this tool are made of non-blunt steel.

If the foil is located in the middle of the wall, a polypropylene pipe trimmer is required, equipped with adjustable knives, which makes it possible to adjust the tool to any diameter. Just like the coupling, the trimmer has a double-sided design (for two different diameters).

Facing polypropylene pipes is cutting the foil from the end to the welding depth. If this procedure is carried out incorrectly, aluminum will interfere with creating a reliable connection between the elements of the system, that is, the weld will not be of sufficient quality. During the operation of the system, water will interact with aluminum, which can lead to leakage and rust formation in heating appliances.

Another way to solve the problem of "how to strip a polypropylene pipe" is a nozzle on a drill (shaver). This method is used for a large amount of work to strip the outer layer of polypropylene and remove the reinforcing aluminum layer, if it is located at the outer surface. The body of the shaver is made of aluminum, the knives are made of tool steel.

Thanks to the shaver, stripping for polypropylene pipes is automated, facilitating and speeding up installation with a large amount of work.

Polypropylene pipes due to operational parameters, aesthetic appearance and ease of assembly, are often used in the installation of engineering communications. Thanks to the reinforcement technology, the reliability and durability of pipes increases while maintaining all the technological characteristics of polypropylene, pipes are not only comparable in their qualities to metal pipes, but also surpass them.

However, for long-term and reliable operation of the piping system, it is necessary correct handling, stripping the ends when connecting.

The reinforced pipe is a product with three layers: two polypropylene and one reinforcing. Structural reinforcing shell ensures strength retention in case of sudden temperature changes.

Such an indicator as the coefficient of thermal elongation is 6% higher for pipes with aluminum reinforcement, which increases the durability and reliability of the pipeline in which reinforced pipes are used.

The presence of an aluminum layer in polymer pipe allows you to maintain high temperatures and prevents interruption of communications in the system. Tempera tour jumps are compensated due to the flexibility of the reinforcing base. Reinforcement is performed in two ways:

1. With fiberglass.
2. With aluminum foil.

Reinforced products are produced both with a solid sheet of aluminum foil and in the form of a mesh with perforations. The viscous polymer flows through the aluminum holes and creates a strong bond with the protective layer, increasing the reliability of tubular products even at elevated high temperature loads.

Why is cleaning required?

If fiberglass reinforcement does not require additional cleaning of the ends of the pipes, then when installing with aluminum, it must be removed and cleaned.

During installation, molten aluminum does not provide a hermetic connection with propylene, and it is required to exclude metal contact with water at the junctions of pipes and fittings, and to avoid corrosive processes.

Attention! During the cleaning process, the oxidized layer is removed and different kind contamination from the surface of polypropylene pipes. Thus, the edge of the pipeline is prepared for a reliable welding joint.

Cleaning methods and technology

Starting the installation of reinforced pipes, you must first select a stripping tool. It can be both manual and mechanical devices.

Market building materials offers big choice pipes made of polymeric materials.

Advances in organic synthesis have made it possible to create materials that show excellent performance characteristics.

Polypropylene products are popular - every second apartment or a private house have plumbing or heating from such pipes.

Technical description

Modern technologies have made it possible to create a durable, lightweight material, which is not subject to corrosion, has good strength characteristics, does not react with aggressive media.

small price, low weight, ease of installation determine the widespread use of polypropylene pipes (what is it).

The industry produces several types of products, some of which contain a reinforcing layer outside or inside the pipe.

Quality soldering such models is possible only in the case of stripping the ends of aluminum foil.

We use two types of shaver:

• manual,
• automatic.

The first ones are used when performing one-time operations, the second one is able to clean pipes in large volumes, which is typical for large construction companies ().

The need for reinforcement

Plumbing or heating system made of polypropylene, in addition to the advantages, has several significant disadvantages.

Despite the ability to transfer water with a temperature of 90-95 degrees and withstand short-term heating up to 100 degrees, the polymer has a high coefficient of thermal expansion (read about the technology for installing metal-plastic pipes in the article).

Flexible Structure will allow the product to restore its shape when the temperature drops.

But such a situation can become critical when the pipeline is hidden in the walls or under the floor.

Adding a layer of fiberglass or aluminum foil to the composition of the product will reduce thermal expansion and avoid deformation when heated.

Reinforcement helps in the linear sections of the pipeline, but there is no foil in the compounds. This leads to softening of the polymer at temperatures above 100 degrees.

In such places, a breakthrough of communications is possible, therefore the use of reinforced products is not recommended for industrial pipelines.

Used to reinforce pipes.:

• fiberglass.
  Structurally, the pipe consists of two layers of polypropylene and a middle layer of a combination of fiberglass and polymer.
  Such products do not need to clean the ends before welding;
• aluminum foil.
  Popular type of reinforcement.
  Manufacturers produce pipes with different foil thicknesses.
  More common are polypropylene pipes reinforced with fiberglass () with a layer thickness of 0.1-0.5 millimeters.
  The metal layer can be located inside the product or cover the pipe from the outside.

Why do you need to clean the ends

In the process of stripping the reinforced product, the metal layer is removed at the place of the future connection with the coupling or fitting.

The need for external stripping occurs when using reinforced pipes with an outer layer of foil. Without removing the reinforcement, it is impossible to solder the pipes.

To remove metal from the surface, a special tool is used (which is needed for the installation of pipes made of cross-linked polyethylene, it is written), which cleans the product to the depth necessary for welding.

Drill bits made for one pipe diameter.

To work with such a tool, it is necessary to prepare the necessary nozzles in advance.

Using a drill will increase the stripping speed, the number of processed pipes and labor productivity.

The nozzle is able to work both with external reinforcement and with internal.

How to choose

Product is selected, according to the type of pipes, and is clamped into the chuck. The disadvantage lies in the high speed of rotation - it is necessary, constantly, to control the process. Otherwise, the pipe may be damaged.

If you want to know how to perfectly clean the end of a pipe before welding, watch the video.

The use of pipes in composite metal structures is very beneficial: pipes give joints increased strength and rigidity, while reducing the mass of the assembly. However, the pairing of pipes with each other is laborious and requires special preparation of the ends. This work can be facilitated by using special tools - pipe trimmers.

The principle of operation of the trimmer for metal pipes

The task of the pipe trimmer is to minimize the gaps that inevitably occur when fitting the ends manually, as well as to give the welded joint sufficient aesthetics.

It is known that when connecting and tie-in steel pipes, depending on the angle of their mutual inclination and diameter, the mutual conjugation curve can be a parabola, an arc, or even a straight line. Therefore, it is very difficult to perform a successful pairing by analytical calculation. The problem can be solved by spatial 3D modeling using the well-known KOMPAS or AutoCAD programs, but in practice they do things differently.

In serial production, pipe trimming is carried out using milling machine equipped with a dividing head. The method is accurate, but requires appropriate equipment, which is not always available. home master. At the same time, having a powerful drill for metal (from 1000 W) and a hole cutter, you can quickly profile the end of any pipe.

Industrial versions of such devices in the special literature are called tube notchers (slot cutters, although they are also capable of performing curved contours).

The pipe trimmer includes:

1. A shaft, at one end of which there is a seat for a drill chuck, and at the other end there is a seat for a hole cutter.
2. Bearing assembly, rotating in which, the shaft receives the necessary rigidity.
3. Body, sometimes with a vise for clamping a tubular workpiece.
4. Rotary device, with which the workpiece can be positioned at the desired angle.
5. Adjusting screw.

With the help of the trimmers under consideration, it is possible to mate pipes with a diameter of 6 ... 75 mm, which in most cases is quite enough. The range of change of mating angles is from 45 to 210 0 . It should be noted that the crown cutter is not included in the device.

For processing long pipes, manual pipe trimmers with a chain clamp are used, and for short products, the supporting and guiding parts of the device are combined in one unit. The safety of work is ensured by the presence of retaining rings, which limit the longitudinal movement of the shaft.

Shaft is the most constructive complex element trimmer. First, it must receive longitudinal movement as the cutter penetrates the pipe metal. Secondly, during milling, vibrations are created, which are caused by a sharp fluctuation in the torque of the base power tool. Therefore, the shaft is made polished, has a sliding fit of high quality accuracy, and the bearings used are needle type, which allow compensation of axial and radial loads.

The price of such devices is from 8000 to 50000 rubles. At the same time, all pipe trimmers of the TT size range are quite compact devices that are fixed in a cartridge lathe. The electric drill is fixed in the same way. When processing pipes of small diameter, the device can rest directly on the floor of the workshop.

Do-it-yourself pipe trimmer

In the mass production of shaped profiled pipes (for example, in sports auto and motorcycle workshops, or in plumbing repair sites) a manual pipe trimmer can be made independently. For this, the initial scheme of the trimmer, which is shown in the figure, is made under the blanks available to the home master.

The design consists of the following parts:

1. Base in which milled grooves are made for mounting a jig. In turn, the shape of the base can be adapted to the existing workbench, work table, etc.
2. L-shaped bracket with three longitudinal grooves, the presence of which allows you to fix pipes of different diameters in the fixture.
3. Crawlers with adjusting and clamping screw.
4. Replaceable presser foot.
5. A bracket that presses the foot to the crawler with screws.
6. Bearing unit.
7. A pivot arm that serves as a bearing surface for the bearing assembly.
8. A shaft that does not structurally differ from a similar part of industrial trimmers.

For the manufacture of the shaft, you can use the front shock absorber strut passenger car(for example, VAZ - they are easier to get at a car service). In addition, the steel grade of the shock absorber strut in terms of its strength and performance characteristics fully complies with the rigidity requirements for high-quality trimming of steel (and, especially, aluminum) pipes. The guides of the rack itself are suitable for guiding the shaft: they have a surface wear-resistant coating based on anti-friction alloys. The ends of the rack, of course, are subject to additional processing - for fastening in a drill chuck, and for installing a hole cutter.

Needle bearings should be pressed into the guides, the size of which is selected according to the dimensions of the guides. Two bearings installed in the guide from the return stroke cylinders of the decommissioned hydraulic press will provide the necessary rigidity and parallelism of the main working unit of the trimmer. Bearings are installed simultaneously from both ends of the housing.

The available advice regarding the installation of fluoroplastic guides should be taken with skepticism, since the bearing capacity of fluoroplastic is much lower than that of bearings.

For the manufacture of other elements of a home-made pipe trimmer, you can use shaped rolled products - corners or channels of the appropriate size. Profiling and making grooves are best done on a jig milling machine, thereby guaranteeing their accuracy and parallelism. It will not be difficult to make a clamping device, for which a new clamp with the required diameter and length is suitable.

The swivel lever must have sufficient rigidity, so for its manufacture it is necessary to use a strip with a thickness of at least 12 ... 16 mm. On the part of the body where the swivel arm is installed, it is worth applying angular risks, along which it is easier to position the pipe.

Trimmer for polypropylene pipes

The need to process the end elements of such pipes is due to the following:

• Low durability of reinforced polypropylene pipes, especially with significant temperature differences;
• Ensuring a stronger connection of the reinforced pipe with reinforcement parts, for which it is necessary to remove part of the aluminum foil;
• For fiberglass pipes, where the aluminum reinforcement is always located in the middle of the pipe wall.

Trimmer for polypropylene pipes with reinforcement includes:

1. Two couplings sized to allow stripping of pipe ends of different diameters (typically 16 to 120 mm).
2. Replaceable steel knives.
3. Pair of rotary handles.
4. Aluminium case.
5. Nozzle for electric drill (shaver).

A shaver is required for external trimming of pipes. It consists of two parts - a guide, which is made of durable D16T duralumin, and a hard-alloy cutting part. When introduced into the pipe, the latter rests on the guide, after which the drill is turned on (you can also use a puncher) and a part of the reinforcing layer of the pipe is cut out. Since the shaver has a certain length, the facing for different pipes always produced at the same length, which facilitates their subsequent connection.

The price of a trimmer-nozzle for polypropylene pipes depends on the diameter, and is 400 ... 2000 rubles. Manual type trimmers are cheaper: from 250 to 800 rubles.