During construction or repair, everyone tries to use the most reliable, strong and durable materials in the room. After all, nobody wants to open communications for repairs in the event of an emergency breakdown. Therefore, in heating systems, water supply and other areas, a metal-plastic pipe is often used. It is characterized by durability and high strength. What is this pipe, how is it arranged and how to choose it correctly? We will talk about this in our article today.
Characteristic
A metal-plastic pipe is a universal product of the industry, with the help of which water and heating systems are laid.
Thanks to the combination of two components (metal and polymer), the engineers managed to create a design that is not afraid of high temperature loads and other negative influences.
Benefits
The main advantages of this design are:
- High service life.
- Low thermal conductivity. Such metal-plastic pipes have zero heat transfer, which is why they are often used for laying hot water pipes.
- Resistance to high temperatures.
- Tightness. The metal-plastic pipe of 20 mm does not pass light and oxygen through itself.
- Frost resistance. The design does not deform even at -50 degrees Celsius.
- Resistance to corrosion. Unlike steel counterparts, such structures are not rusted at all.
- Lack of expansion at thermal influence.
- Resistance to salt deposits.
Design
No matter how thick the metal-plastic pipe (16 mm or 20), it has the same structure and construction. And it consists of several layers:
- reinforcing;
- internal;
- external.
Reinforcing layer
In fact, this is the bearing part in the entire structure. This layer is made of aluminum. Thanks to this, high flexibility and, at the same time, the strength of the polymer material are ensured. This layer performs several functions at once:
- Protects the structure from linear expansion. This can happen when the plastic layer is heated.
- Protects the pipe from mechanical damage. When bending, the integrity of the structure is fully preserved. This is a particularly relevant characteristic for installation in hard-to-reach places.
- Pressure drop protection. The higher this parameter, the thicker the layer of aluminum. As a rule, the thickness ranges from 15 to 60 hundredths of a millimeter.
- Protection against oxygen penetration. This helps to prevent the formation of rust and other deposits in the cavities of the structure.
Which plastic pipes are better to use? If repairs are made in a house or apartment, the most optimal choice is products with a thickness of 0.3 to 0.5 mm. Such designs have high strength and at the same time quite flexible, which will allow installation of metal-plastic pipes in difficult areas without problems.
Why not choose products with a thick reinforcing layer? There are two reasons for this. Firstly, such designs are much more expensive. And secondly, the installation of metal-plastic pipes with a thick reinforcing layer is quite difficult. At the same time, you cannot buy very thin products. This applies to pipes with a layer thickness of less than 30 hundredths of a millimeter. Such structures can be deformed even with slight bending.
Outer and inner layer
Of great importance is also the material of the outer and inner layer of pipes. In the manufacturing process, the linear PE-RT polymer or PEX polyethylene is used. These components are characterized by high operational characteristics, due to which they provide structural strength and reliable protection from the environment.
Also in the market of building materials you can find low-pressure polyethylene. These include materials with the following markings:
When choosing, it is worth paying attention that the above components do not differ in resistance to ultraviolet, which is why they quickly become worthless. Last Labeled Polyethylene (PE-RS) also has temperature limits. During operation, the heating should not exceed 75 degrees Celsius. Otherwise, the polyethylene will begin to melt. This leads to involuntary deformation of plastic contraction, and then to pipe rupture. You should not purchase products with this marking, although they are the most affordable in terms of price in the market.
What else to look for?
When buying, it is worth paying attention not only to pipe marking. The following parameters must also be considered:
- The name of the manufacturer.
- Stitching method.
- Pressure rating
- Suitable for transporting the product.
- Date of manufacture.
- Certificate of conformity.
About Resource
The average life of this type of pipe is about 30-50 years. Manufacturers themselves give a ten-year warranty on their products. However, it should be borne in mind that such factors significantly affect the resource:
- High pressure (more than ten atmospheres).
- The presence of sunlight.
- Contact with high temperatures from the outside.
Only subject to the rules of operation, the product will serve the time allotted by the manufacturer.
Products for heating systems
It is worth talking about these types of structures. Metal-plastic pipes for heating are designed for a temperature of 95 degrees Celsius. This parameter is operational for products. In this situation, the product does not deform and does not lose its characteristics. But the temperature of 110 degrees or more is considered already emergency. Of course, wear does not occur immediately. Each pipe has its own short-term safety factor. But if this temperature acts constantly, the productās life will be reduced several times.
And what does the manufacturer say about cold weather operation? The temperature threshold at which the pipe with the liquid does not deform is -20 degrees Celsius. An emergency indicator is 40 or more degrees of frost. In this case, leaks may occur.
Dimensions
When choosing metal-plastic pipes for heating or water supply, one should also be guided by the length of the product. Typically, such designs are sold in bays ranging in length from 50 to 200 meters. But you can buy products in short. It all depends on the scale of the repair.
It is still important to consider the inner diameter. The most thin is considered a metal-plastic pipe 16 mm. What to choose for a private house or apartment? Experts advise buying small diameter products. A metal-plastic pipe of 20 mm would be the best choice. But for small rooms, a 16 mm model is enough.
About installation
To connect the pipes, you must have special fittings. They will allow you to make turns, wiring and installation of structures of different diameters. For example, a 16 mm metal pipe can easily be combined with a 20 mm pipe. And vice versa. But in order for the structure to be airtight, it is worth using special presses for fastening. For plastic pipes sold a whole set of devices. They can be either mechanical or electrical. What are presses for plastic pipes? These are crimping pliers with handles, which are supplied with couplings of different diameters for crimping. There are several types of fittings for connecting plastic pipes:
- Press fittings.
- Collet.
- Threaded.
- Compression.
All of them differ in diameter and are made of different materials. But, as practice shows, the most optimal choice is threaded elements.
Installation can be done in several stages. To do this, you must:
- Cut the desired piece of pipe with special scissors.
- Remove metal burrs from the edges with a file.
- Apply silicone grease to fitting fitting.
- Install the union nut on the pipe and crimp ring.
- Push the product onto the fitting fitting (it is important not to damage the o-rings).
- Tighten the connection with wrenches.
For crimping press fittings, a special tool is used - press pliers. An example of his work can be seen in the photo below.
Below we look at the most popular manufacturers of plastic pipes, which received rave reviews.
Stout
This is an Italian company manufacturing pipes for heating. User reviews highlight such advantages as design reliability and safety. These products are excellent for our operating conditions. Stout produces pipes with a diameter of 16 millimeters. The total wall thickness is two millimeters. The volume of water in one meter is 0.11 liters. It is made of mesh polyethylene. The pipe is highly flexible, making it suitable for laying bends with a small radius.
"ProExpert"
This is a Russian manufacturer that has been manufacturing pipes for twenty years. This company produces products with a diameter of 20 mm from PPR-AL plastic. The reviews say that ProExpert products are highly temperature resistant.
"Valtek"
This is a Chinese manufacturer. Customers say these pipes are ideal for radiator heating. The manufacturer provides a ten-year warranty. However, the reviews noted one minus. This is a small pipe thickness (only 12 millimeters). But at the same time, the product repeatedly withstands significant temperature extremes. It is also worth noting that the Valtek pipes are sewn with an organosilanide method.
Prandelli
This is a rather rare company in Russia. These pipes are made in Italy. Differ in the presence of two-layer polyethylene. The reviews say that the service life of such products is the highest. But there is a minus - a big price. Such products cost twice as much as the Russian counterparts from ProExpert. The diameter of the pipes is 16 millimeters, the type of crosslinking is RE-XB.
Henco
These metal-plastic pipes are produced in Belgium. Their main difference is that they are covered with colored corrugation. It is very convenient for differentiating hot and cold liquids. It is noted that such products are very durable and convenient to install. Service life - up to 50 years, while the warranty from the manufacturer is 12 years.
Aventop
These are pipes from a German manufacturer. The company launches the Copipe HS line, featuring a three-layer construction. Its main feature is that if the outer layer is damaged, the characteristics of the pipe are completely preserved. She does not need replacement and any repair.
Such a damaged pipe can withstand pressure up to ten atmospheres and a temperature of up to +100 degrees Celsius. As for the size, Aventop is a 16 mm metal-plastic pipe. Sold in bays of 50, 100, or 200 meters. It keeps its shape well.
Conclusion
So, we found out what a metal-plastic pipe is. As you can see, this product has a lot of advantages compared to conventional steel or plastic structures. Such pipes can withstand large temperature differences, can take any shape and are connected using conventional fittings. In addition, they can be used both indoors and outdoors (and even underground). As for the choice, an ideal option would be a product with a diameter of 16 or 20 millimeters with a two- or three-layer construction. It will be a cheap and flexible pipe that can withstand all the loads placed on it.