The main component of any engineering networks is certainly a pipe. Today, the metal-plastic pipe is very popular. Technical characteristics allow the use of this material both in everyday life and in production. In the household, these products are used for laying underfloor heating, building heating systems and plumbing.
What is a metal-plastic pipe
The metal-plastic pipe consists of a bearing aluminum layer, as well as a thick layer of polyethylene attached to it from the inside and outside. This structure allows you to profitably use the positive qualities of two different materials and neutralize the negative ones.
The PE layers protect the aluminum from corrosion and build-up on the inside, while the aluminum reduces the significant expansion of the PE and UV exposure, and adds rigidity to the product. The service life and reliability of pipes depend on the quality of the adhesive that holds all layers together. Glue Excludedelamination during installation and temperature changes.
In order to make the right choice, you need to know what types of metal-plastic pipes are and how to use them.
- For plumbing. In this case, you can use any product, since there are no temperature differences.
- For heating and hot water systems. Here it is necessary to pay attention to the marking, it should contain designations like PE-RT-AL-PE-RT or Pex-AL.
Metal-plastic pipe. Specifications
- Manufacturers mainly produce pipes with a diameter of 16 mm, 20 mm, 26 mm, 32 mm and 40 mm. But if you wish, you can find products in 50 mm and 63 mm.
- Metal-plastic pipe 16 mm long, 1 linear meter weighs approximately 100 g.
- Working pressure of the material - 10 atmospheres.
- Maximum working temperature of products - 95 °С. Permissible short-term exposure - 110 °C.
- Pipes are available in 2mm, 2.5mm and 3mm wall thicknesses.
- Manual bending radius is 80-550mm, with pipe bender 45-180mm.
The minimum diameter of metal-plastic pipes is permissible only when normal pressure is maintained in the central system. When constructing extensive wiring in a private house, it is better to use products with a caliber of 32 mm and 40 mm.
The only negative that plastic pipes have is the price. It is quite high, especially for foreign manufacturers. However, their value for moneybetter than plastic and steel.
Advantages of plastic pipes
Metal-plastic pipe, the technical characteristics of which, despite the popularity of the material, are not known to everyone, has some competitive advantages:
- durability (pipe life can be up to 50 years);
- no toxicity;
- resistance to aggressive environments;
- light weight, which allows the installation of engineering systems in a short time, while without unnecessary load on the foundation;
- easy repairs;
- convenience in delivery - pipes are sold in large meters in bays, which minimizes waste when measuring and cutting;
- no stray currents;
- good plasticity, thanks to which the pipes do not break when water freezes in them;
- no need for welding, masking and painting;
- high sound absorption, which makes it possible not to use additional insulation;
- no linear stretching.
Installation of plastic pipes
To assemble a quality system, you need to know how to connect metal-plastic pipes. Installation involves the use of special fittings, which are divided into two types:
- Press fittings, or crimp fittings.
- Compression or threaded.
Installation of metal-plastic pipes using press fittings
Usepress fittings allows you to get a one-piece and very reliable design, which makes it possible to avoid leaks. Therefore, with hidden wiring, experts advise working with this type of connection.
In order to install a compression fitting, you need to stock up on press tongs. This special tool can be manual or hydraulic. Before you get started, you need to understand how to connect metal-plastic pipes using press fittings.
- To begin with, the product is cut with special scissors.
- The end of the material is processed with a calibrator - a special reamer that simultaneously aligns the cut and removes the internal chamfer.
- The outer edge of the pipe is machined with a beveler.
- The sleeve is removed from the fitting, after which the sealing rings are carefully examined. They must not be damaged or defective. After checking, the sleeve is installed in place.
- The fitting of the connector is inserted into the pipe as far as it will go.
- Press tongs are installed over the sleeve, after which the tool handles are connected.
Re-crimping of the same sleeve is prohibited, therefore, if the fitting was installed poorly, it should be replaced.
Press fittings are especially convenient when different diameters of metal-plastic pipes that need to be connected to each other. Parts fastening products with the same caliber are called straight. And those that connect slices of different diameters are transitional.
Installation of metal-plastic pipes with compression fittings
This connection method is especially popular for self-assembly, since it does not require the use of special tools to use it. The tightening can be done with two ordinary wrenches. The operation sequence is shown as the following list:
- The pipe, as in the case of press fittings, must first be prepared.
- A nut is initially put on the cut, and then a ferrule.
- The connection fitting is inserted into the product.
- The ferrule goes to the fitting, followed by the nut that closes the ferrule.
- Using two wrenches to tighten the nut.
No assembly can do without fittings, in which metal-plastic pipes take part. The price of press parts is somewhat higher, in addition, such installation is considered one-time, since the connection is non-separable. And this is perhaps the main drawback of such fittings, despite this, they perform their direct duties perfectly.
Metal-plastic pipe, the technical characteristics of which are very attractive, is becoming more and more popular. Today, the product line covers over 25% of the entire market of metal-polymer products, which are involved in various construction and installation works.
