The main component of any engineering network is certainly the pipe. Today, a 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, the construction of heating systems and water supply.
What is a plastic pipe
The metal-plastic pipe consists of a supporting aluminum layer, as well as a thick layer of polyethylene attached to it from the inside and outside. Such a structure allows the beneficial use of the positive qualities of two different materials and neutralize the negative.
The polyethylene layers protect aluminum from corrosion and the formation of overlays on the inside, while aluminum reduces the significant expansion of polyethylene and ultraviolet radiation, and also gives the product rigidity. The service life and reliability of the pipes depend on the quality of the adhesive that holds all the layers together. Glue eliminates delamination during installation and temperature extremes.
In order for the choice to be right, you need to know what types of metal-plastic pipes are and how to apply them.
- For water supply. 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 must bear designations like PE-RT-AL-PE-RT or Pex-AL.
The pipe is metal-plastic. Specifications
- Manufacturers mainly produce pipes with a diameter of 16 mm, 20 mm, 26 mm, 32 mm and 40 mm. But if you want, you can find products of 50 mm and 63 mm.
- A 16 mm metal-plastic pipe 1 meter long weighs approximately 100 g.
- The working pressure of the material is 10 atmospheres.
- The maximum working temperature of the products is 95 ° C. Permissible short-term exposure - 110 ° .
- Pipes are available with wall thicknesses of 2 mm, 2.5 mm and 3 mm.
- The radius of the manual bend is 80-550 mm, by means of a pipe bender - 45-180 mm.
The minimum diameter of metal-plastic pipes is permissible only when normal pressure is maintained in the central system. When constructing an extensive wiring in a private house, it is better to use products in caliber 32 mm and 40 mm.
The only negative that metal-plastic pipes have is the price. She is satisfied high, especially from foreign manufacturers. However, the price / quality ratio is better than plastic and steel.
The advantages of plastic pipes
A 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 service life can reach 50 years);
- lack of toxicity;
- resistance to the effects of an aggressive environment;
- light weight, which allows installation of engineering systems in a short time, while without unnecessary burden on the foundation;
- easy repair;
- convenience in delivery - pipes are dispensed with a large footage in bays, which ensures minimization of waste during measurement and cutting;
- lack of stray currents ;
- good ductility, due to which the pipes do not break when water freezes in them;
- no need for welding, masking and painting;
- high noise absorption, which makes it possible not to use additional insulation;
- lack of linear tension.
Installation of metal-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.
- Compression or threaded.
Installation of plastic pipes by means of press fittings
The use of press fittings allows to obtain an integral and very reliable design, which makes it possible to avoid leaks. Therefore, with a hidden wiring, experts advise working with this type of connection.
In order to install a crimp fitting, you need to stock up on press tongs. This special tool can be manual or hydraulic. Before you begin, you need to understand how to connect plastic pipes using press fittings.
- To begin with, the product is cut using special scissors.
- The end of the material is processed by a calibrator - a special scan, which simultaneously evens out the cut and removes the inner chamfer.
- Using the chamfer, the outer edge of the pipe is machined.
- The sleeve is removed from the fitting and then the sealing rings are carefully inspected. They must not be damaged or defective. After checking, the sleeve is replaced.
- The connector fitting is fully inserted into the pipe.
- Press tongs are installed above the sleeve, after which the handles of the tool are connected.
Repeated crimping of the same sleeve is prohibited, therefore, if the fitting was installed poorly, it should be replaced.
Particularly press fittings are convenient when there is a different diameter of 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 plastic pipes by means of compression fittings
This method of connection is especially popular with self-assembly, since you do not need to resort to special tools to use it. Tightening can be done with two ordinary wrenches. The sequence of operations is represented by the following list:
- The pipe, as is the case with press fittings, must first be prepared.
- A nut is first put on the cut, and then a crimp ring.
- A connection fitting is inserted into the product.
- The crimping ring goes to the fitting, followed by a nut that overlaps the ring.
- Using two wrenches, tighten the nut.
Not a single assembly can do without fittings, in which metal-plastic pipes take part. The price of press parts is slightly higher, in addition, such installation is considered one-time, since the connection is not separable. And this is perhaps the main drawback of such fittings, despite this, they perform their direct duties perfectly.
The metal-plastic pipe, the technical characteristics of which are very attractive, is becoming increasingly popular. Today, the product line covers over 25% of the entire market for metal-polymer products, which is involved in various construction and installation works.