Do-it-yourself procedure for replacing polypropylene pipes

Technological progress in the field of water supply network maintenance is constantly moving forward. Means of storage and transfer of water, for the manufacture of which ferrous metals (cast iron and steel) were used, are being inexorably squeezed out. They were replaced by completely new, light, strong and durable polypropylene pipes. Their replacement, that is, the arrangement of a new water supply network, includes a number of mandatory operations. Having carefully familiarized yourself with the technological features of the production process, you can independently mount a water supply system from polypropylene.

Scope and advantages of pipes made of polypropylene

Hollow products of circular cross section made of polypropylene are very popular due to the fact that they have a much longer life than metal counterparts. Manufacturers guarantee the safety of a properly installed water supply network for 30-50 years. In addition, polypropylene is devoid of one of the main drawbacks that cast iron and steel products sin: it is not subject to corrosion.

The main areas of application for polypropylene carriers are the installation of plumbing and plumbing systems. The maximum temperature at which systems made with polypropylene can be operated is 140^aboutC. This is quite enough for installation in a domestic water supply, since the temperature of the water in the heating system is much lower than the boiling point.

The main design advantages of polypropylene coolants:

• strength and elasticity of the material.
• reliability.
• high savings in thermal energy.
• good soundproofing.
• significantly less, in comparison with metal, the mass of the installed water supply.

The main design drawback of polypropylene products is the limitation on the water temperature in the pipes. It cannot be raised above 140 degrees. In addition, it is necessary to carefully protect polypropylene from the effects of aggressive environments — alkalis and acids.

Polypropylene costs an order of magnitude less than metal and metal-plastic. It is environmentally friendly, since the chemical composition of the transported liquid is the same in any section of the pipeline. The only condition for all these advantages to be converted into money savings is compliance with the rules for installing plumbing or plumbing systems.

Choosing pipes for home plumbing

From the moment when the decision is made to overhaul the water supply system at home, you need to be very careful about the choice of the main material. Five types of pipes are widely used as a replacement for metal pipes:

1. Metal-plastic. Can pass media at temperatures up to 900 ^aboutC, but they bend very badly.

2. Polyethylene. Installation of systems can be carried out at negative temperatures and wide pressure ranges. The most suitable material for urgent repairs.

3. PVC. They cannot be used for laying water pipes due to the presence of the hazardous element chlorine.

4. PES (made of cross-linked polyethylene). Products from this material can be used in any transportation and heating systems.

5. Polypropylene. Due to their multi-layer construction and excellent performance, they are the main material for the installation of plumbing systems.

Polypropylene is much more popular than other materials that are used to make plumbing systems. Only cross-linked polyethylene is comparable to polypropylene in terms of performance. But it is less profitable from an economic point of view, since it is more expensive than polypropylene.

It is necessary to pay special attention to the quality of the plumbing assembly in the case when polypropylene products will be used to install heating pipes in the apartment. If errors are made during the installation process, there may be a risk of damage to the installed equipment. To avoid additional financial costs, it is necessary to calculate the system and the correct selection of measuring instruments.

Rules for choosing the size of a polypropylene pipe

Replacing metal pipes with polypropylene pipes involves careful calculations. This is necessary for the normal functioning of the system during the entire declared warranty period for polypropylene products. Four types of pipes are widely used — PPs, PPR, PPB and PPH. Trade networks receive products with a diameter of 16 to 1200 mm. For heating systems, the use of pipes with a diameter of 16-32 mm is optimal. Determination of the estimated diameter of the water supply system helps to save on the cost of materials. Wider (40-50 mm, and in some cases up to 110 mm) pipes are used for sewer installation.

Choosing the right size depends on two factors:

• the total length of the system;
• number of water points.

For inlet sections of the system, the minimum outer diameter must be 32 mm. The internal wiring of the system can be carried out using a diameter of 16-20 mm.

The internal diameter of a polypropylene pipe, necessary for the normal operation of the system, can be determined using a simple mathematical calculation:

The speed of water movement in the pipe is different:

• for thin (10-25 mm) — 0.7-1.2 m / s.
• For thick (over 25 mm) — 1.5-2.0 m / s.

The difference is explained by the fact that as the diameter decreases, the ratio between the surface and the lumen decreases. If you choose a pipe that is too thin, the permeability will decrease due to the fact that the speed of water movement decreases when the flow hits the inner wall.

The permeability in polypropylene carriers of the water supply system depends on the following factors:

• the number of turns and joints of pipes of different sizes;
• the total length of the pipeline;
• pressure values ​​in the system;
• internal diameter of main pipes.

The pipes selected for installation in the system must comply with the standards. The best way to avoid problems is to purchase materials from one manufacturer. This will guarantee the same regular geometric shape, the smoothness of the pipes and the absence of damage throughout the length of the measured segments.

Pipe soldering rules

To securely fasten the welded edges of the pipe together, it is necessary:

• to measure the welded pipe sections;
• Make a bevel —

— with a slope of 15^about and deepening by 2-3 mm (standard DVS-2207-1, Germany).

— with a slope of 45^about and deepening by 2/3 of the outer diameter (standard of the Russian Federation).

The soldering iron should be installed on a special stand. The optimum temperature for heating the working surface is 260 degrees.

The fitting is installed on the mandrel — a special nozzle for welding. The heated pipe is inserted into the sleeve. At the same time and very quickly, the parts removed from the heater are connected to each other. The exposure time of the connection depends on the size of the outer and inner diameters. When overexposure, there is a danger of joint deformation and loss of elasticity. Having brought the sleeve to the stop in the joint, you should stop moving, since if there are undesirable sagging inside the pipe, its conductivity will be impaired.

The exposure time of the connected pipes on the machine, depending on the diameter, seconds:

• 20 mm — 5;
• 25 mm — 7;
• 32 mm — 8;
• 40 mm — 12;
• 50 mm — 18;
• 63 mm — 24.

The easiest way to avoid mistakes is to measure the depth of the sleeve. By measuring exactly the same distance on the pipe, you can visually control the moment of the joint. The connection speed of the heated pipe and the coupling must be maximum. In order to avoid a decrease in the quality of the welded joint, it is strongly not recommended to rotate the parts to be joined around its axis.

Stages of installation of a polypropylene water pipe

The decision to replace the pipes of the old water supply with more modern ones made of polypropylene forces us to adhere to a simple plan of action:

1. Making a sketch of the project.
2. Material calculation (number of pipes, fittings, couplings and other connecting elements).
3. Procurement of basic and auxiliary materials.
4. Overlapping of the centralized water supply.
5. Dismantling the plumbing.
6. Installation of new equipment and assembly of the system.
7. Checking the performance of the newly installed plumbing.
8. Construction debris removal.

Installation can be partial or complete. During partial replacement, new pipes made of polypropylene are put in place of damaged old pipes. It must be remembered that when installing a hot water supply system, it is imperative to install a pressure reducer. In addition, collapsible connections must be located in areas of the system that are open to permanent access. Hot water media must have a water temperature limit of 75 degrees Celsius.

It is not recommended to mount all pipes of the plumbing system on fixed fixtures. This can be done only in those places where there are pipeline risers, joints and turns. On straight sections, the fastening of pipes to the wall must be mounted to be movable. Rules for the use of connecting elements:

• Coupling — for joints between straight segments, changing diameters and switching to a connection using a thread.
• Elbow — for turning the pipeline.
• Tee — for mounting a branch.

Important! For cold water supply, products marked PN10 are used, for mixed — PN20 or PN25 (reinforced).

Operation and repair of polypropylene pipes

Like any other material, polypropylene, in addition to advantages, has a number of disadvantages. Its performance may be affected by:

• high impact loads;
• excessively high water temperature;
• exceeding the nominal pressure;
• interaction of pipes with chemically aggressive substances;
• mistakes made during installation.

Before starting repair work, you should carefully inspect the water supply and identify the causes of technical problems.

If a depressurization is diagnosed in the area of ​​​​the joints (places of installation of measuring equipment, connecting fittings and transitions to other types of media), then there is a misalignment of the sealing ring installed at the joint, or the fitting is faulty. To carry out repairs in the apartment you need:

• shut off the water supply;
• dismantle the failed joint;
• restore the tightness of the system section at the site of the leak using a welding machine;
• install a new fitting.

In addition to a soldering machine, rubber clamps and special glue can be used to create sealed joints in polypropylene products. As a patch, a piece of thin rubber, carefully processed and degreased with alcohol, is used. You can fix the clamp with a wire.

This repair is temporary. A new fitting must be installed on the failed joint as soon as possible.

To ensure the smooth operation of the heating system, it is necessary to install a sufficient amount of measuring equipment to control the pressure and temperature of the water. Automation should warn about all problems in time. In the event of a breakdown, do-it-yourself repair of the system will be technically simple. Also, it will not cause financial difficulties. If you follow the rules for operating the plumbing system, it will last a long time and will not cause problems associated with the repair or replacement of equipment.