Modern water pipes are rarely made of metal. There were at it worthy competitors - polymers which gradually supersede it in many areas. One such material is low pressure polyethylene. This material is made of pipes for pressure pipelines, that is, for water pipes and even for gas pipelines. This kind of material is becoming more popular, since the connection of polyethylene pipes is easy to do by one's own hands. You just have to follow very simple rules.
Advantages and features of application
Polyethylene pipes are made of low pressure polyethylene. Abbreviated this material is labeled as HDPE. It is distinguished by its high strength and elasticity, has good operational properties:
- chemically neutral, can be used to transport food;
- smooth walls prevent the formation of plaque inside;
- not subject to corrosion;
- small coefficient of thermal expansion - about 3% with maximum heating (up to + 70 ° C);
- normally react to the freezing of water inside, due to the elasticity increase in diameter, and after thawing take the original dimensions.
One thing to remember! If you need pipes that are resistant to freezing (for example, for the installation of a water pipe in the country), when selecting, look at the description or technical specifications. Not all types of copolymers that are used for the production of pipes normally tolerate freezing. So be careful.
The main disadvantage of polyethylene pipes is the limitation on the temperature of the transported medium: it must not be higher than +40 ° C, that is, only cold water can be made from HDPE, it can not be used for hot water and, moreover, for heating.
Another thing: polyethylene does not tolerate UV radiation. With constant exposure to the sun, the material loses its elasticity, and, after a while, breaks down (some manufacturers make HDPE tubes resistant to ultraviolet light, but they are more expensive). Therefore, the open laying of water pipes from plastic pipes is very undesirable. But to hold a pipe in a trench from a well or a well to the house, it is even possible to make cold water distribution around the house. This is quite an economical and convenient solution, since the installation and connection of polyethylene pipes is not very difficult. If it is a detachable connection, then no equipment is needed for it. Only fittings and hands are needed.
Which polyethylene pipes are better
Polyethylene of two brands - PE 80 and PE 100 - is used for the production of water pipes. The hundredth polyethylene is denser and stronger than the eightieth. For water supply systems of a private house, the strength of PE 80 is more than enough - they withstand a pressure of up to 8 atm. If you like a large margin of safety, you can take them from PE100. They work normally and at 10 atm.
What you should pay attention to is the country in which the product is manufactured. Leaders in quality are European producers. High accuracy of the design guarantees high reliability of the system. Average quality and prices - for the Turkish campaigns, in the cheaper price segment, the Chinese manufacturers. The quality of them, as usual, is also much lower. Councils here are difficult to give, each picks up at its own discretion (or what is in the region).
Types of connections of HDPE pipes
The connection of polyethylene pipes is of several kinds:
- detachable (on fittings or couplings);
- all-in-one by welding:
- using a special welding machine;
- electric couplings - inside of these couplings a heater is built in, when an electric current is applied to it, the polyethylene heats up and fuses.
Welded mainly pipes of large diameters, which are used to create trunk pipelines. Pipes of small diameters - up to 110 mm, used in private construction, are mostly connected by means of fittings. Clutches are used more often in repair work, as their installation takes more time.
Fittings for polyethylene pipes are shaped parts (tees, crosses, corners, adapters, couplings), with which the required configuration of the system is created. Since the independent connection of polyethylene pipes is carried out more often with the help of fittings, let's talk about them in more detail.
Assembly on compression fittings
With one or two sides of the fitting (sometimes with three), an entire system is installed that provides the connection. The fitting itself consists of:
- a clamping nut;
- collets - plastic ring with oblique incision, providing tight coverage of the pipe;
- the thrust ring;
- gasket, which is responsible for the tightness.