Plastic pipes for plumbing. Kinds. Comparison

For many years, galvanized steel pipes were the main material for the creation of water supply systems. But, over time, their popularity has decreased in view of the emergence of a new material such as polymers, of which now make plastic pipes for water supply. They made the same revolution in the market as cast iron at the end of the 14th century.

Contents 

• 1 Advantages and disadvantages of plastic pipes
• 2 Kinds of plastic pipes
  • 2.1 PVC pipes (polyvinyl chloride)
  • 2.2 Polypropylene pipes
  • 2.3 Polyethylene pipes
  • 2.4 Cross-linked polyethylene pipes
  • 2.5 Metal-polymer pipes
• 3 Methods of installation of plastic pipes for plumbing
• 4 How to choose a pipe for water?
• 5 What are we choosing?

The advantages and disadvantages of plastic pipes

Today, polymer products have several varieties, characterized by different properties, advantages and disadvantages. Common advantages of using plastic pipes for water supply include:

• Long service life. In contrast to steel pipes, plastic pipes for water supply have a service life of 50 years and more. This is four times the service life of iron and steel;
• High corrosion resistance. Due to the fact that polymers can not enter into reactions of the electrochemical type, they are perfectly resist the effects of the environment;
• Such pipes have low weight, low heat-conducting properties and are considered environmentally friendly;
• They perfectly isolate the sound, so that the noise from the water inside the pipe is poorly distinguished by the human ear;
• Installation and disassembly of pipes from similar materials is easy, simple and fast.

The disadvantages of plastic pipes for plumbing are very peculiar and are not obvious drawbacks. Among them, it is possible to single out only the fact that they cannot be used among fire-fighting water supply systems, have limitations on the temperature of the water being conducted and differ in their own installation technology for each type of pipe and polymer.

Types of plastic pipes

PVC pipes (polyvinyl chloride)

PVC plastic pipes for water supply are pioneers in the use for the manufacture of water supply systems. It implies the arrangement of hot and cold water supply systems. They are successfully used for technical and food water. The following features distinguish them from other types:

• Can be used with both external and internal gasket;
• They have two types of connections: in the socket or by means of cold welding, special tools or construction skills are not required for installation;
• When installing a PVC water supply system, special fittings must be used;
• Have an economical cost, are among the cheapest among systems of other polymers or galvanized pipes.

Polypropylene pipes

They may be multi-layered or single-layered. The standard pipe length is four meters, and the outer diameter varies from 16 to 125 millimeters. The joints of pipe fittings are arranged by means of special mounting equipment using the method of thermoplastic welding. Special fittings with existing threads allow you to connect polypropylene pipes with metal risers. Most often used in the arrangement of cold water systems, less often - hot or heating.

Polyethylene pipes

These plastic pipes for water supply differ from other types by the lowest limiting temperature at which they can work. It is equal to -20 degrees Celsius. They are divided into two types: "C" - medium and "T" - heavy. In the first case, the working pressure is about six atmospheres, and in the second up to 10 atmospheres. Widespread pipes of this type received in the arrangement of sewage and drainage systems. The diameter varies from 20 to 160 millimeters. The connection is made by brass or polypropylene fittings, as well as electrofusion couplings or butt welding. Polyethylene pipes are produced only at 15 plants of the Russian Federation and neighboring countries.

Cross-linked polyethylene pipes

They are created by processing the material under high pressure, as a result of which they become more durable and resistant to various temperature influences. The process is called "stitching." There are several ways to crosslink polyethylene:

• Peroxide;
• The use of silane (extremely poisonous substance);
• The method of learning the flow of electrons;
• The use of nitrogen compounds.

Such pipes are reliably protected from the penetration of oxygen inside, are used to create a system of snow melting, installation of water floors and water mains.

Metal pipes

The youngest subspecies of plastic pipes for plumbing. For the first time appeared about one decade ago in the territory of England. They are a type of metal-plastic pipes, but they are equipped with a special layer of aluminum foil. Thus, the creators have achieved a reduction in the coefficient of linear expansion of the pipe. Have a complex composition of five layers.

Main advantages:

• Not subject to wear and structural changes in the design;
• Able to withstand loads at temperatures up to 95 degrees Celsius and pressures up to 10 atmospheres;
• Great for use in drinking water systems;
• Do not let in gases or oxygen;
• Keep a form at a bend;
• There are two ways to connect: screwing and pressing;
• Can have a diameter of 16 to 110 millimeters.

Installation methods of plastic pipes for water supply

1. Welding or so-called soldering pipes. Today it is actively used in PPR plastic pipes for water supply. The process is based on melting the ends of the pipe and fitting in a special welding machine and then fastening them together. This is how a solid connection is achieved.

Pipe welding example:

2. Using crimp fittings with a special press machine. This method is applicable to metal and plastic pipes. Pipe joints are interconnected by special fittings and then pressed by a special press machine.

3. Flange method. With this method, the pipes can later be corroded among themselves. The connection takes place with a special flange. Special rubber gaskets are responsible for tightness.

How to choose a pipe for water?

What are we choosing?

Among all classes of pipes made of polymers it is difficult to choose one, it all depends on the requirements for the water supply system. We try to work with metal-plastic pipes and pipes made of cross-linked polyethylene. There are several reasons for this.

The first and most important - these pipes are more environmentally friendly than the same CPD pipes. Second, these pipes have a solid structure and their joints are all on the surface. And the third reason - pipes are relatively affordable.