How to connect the hdpe pipe

Little construction will do without laying pipelines. For their installation, you can use various pipes, for example, polyethylene, created under low pressure (HDPE). Such products are used both in pressure and free-flow systems. But to use such pipes, it is necessary to know the method of working with them. This article will explain how to connect the HDPE pipe.

The advantages of using HDPE pipes

To date, pipes made of polyethylene under low pressure, are in great demand. This is facilitated by the positive qualities of such products. Namely:

• Long service life (over 50 years).
• Immunity to aggressive media.
• Corrosion to such pipes is not terrible.
• It is possible to carry out laying in the trenchless way, which significantly reduces the cost of all work, but limits the period of use of such water supply.
• The inside of the pipe is very smooth. This prevents the formation of deposits and growths, which eliminates the appearance of blockages.
• The pipes are very light, it greatly facilitates and accelerates the laying of pipelines;
• Products from PND are not afraid of temperature drops.
• Pipes have great plasticity. The constructed pipeline easily transfers ground movements. That is why such pipes are often used in earthquake-prone regions.

But there are some drawbacks. So, pipes from PND badly transfer ultraviolet radiation. Also, such pipelines are not designed for pumping liquids with high temperatures, as a result of which they can be deformed.

Butt welding

Special equipment is used for butt welding of polyethylene pipes. At the same time, it is very difficult to perform such work independently; for this, it is necessary to have a special qualification. Welding pipes PND end-to-end is carried out in two ways:

• using a mechanical welding machine;
• with the use of electro-hydraulic welding unit.

The first method is used only when installing pipelines with low pressure. These include sewage systems and drainage at industrial enterprises. Electro-hydraulic equipment capable of creating pipelines for any purpose. Compounds made using this method are strong and durable. The pipelines themselves are able to withstand high pressure and any mechanical effects.

Various parts of HDPE can also be used for pipe welding. Thus, the industry produces bends, crosses, tees, transitions, etc. With their help, you can create a pipeline system of any configuration.

But, as mentioned above, welding requires the use of special equipment and the availability of sufficient experience. For these reasons, this method is rarely used in everyday life. A simpler, but no less reliable way to connect HDPE pipes (and not only to each other) is to use fittings.

Use fittings

The connection of HDPE pipes can be carried out using special fittings. Such structures are used to create communications from pipes of small diameter (up to 50 mm). You can use the following types of fittings:

• electrowelded;
• compression;
• reducing

The first option is a clutch with an electric heating element inside. When connected (after connecting to electricity), the fitting heats up and melts the polyethylene. The result is a strong and reliable connection, but not folding.

For the work it is necessary to pre-clean the pipe and fitting of dirt. Then they are set on the same axis, while achieving the stillness of the whole structure. After that, the connecting element is connected to a specially designed for this purpose current source. As a result of heating, the plastic begins to melt, hermetically connecting all the elements. More information about working with such connecting elements can be found by viewing videos from the Internet.

The easiest way to connect the HDPE pipe is to use a compression fitting. Anyone can cope with this task, even without possessing any skills. These fittings consist of:

• plastic case;
• sealing rings;
• clamping rings (they protect the connection from mechanical damage);
• bushings;
• cover nuts.

Before you begin, you need to disassemble the design of the connecting element. Then at the end of the pipe mark the distance at which it should go to the fitting. Further, having previously moistened in water, we put on the connecting element. Last action? This is a tightening of the cap-nuts (in this case there is no need to apply excessive efforts). The result is a connection without the risk of leakage, besides collapsible.

In addition, compression fittings have another plus - it is the ability to produce connections for different (by material) pipes. Very often when repairing an apartment it is required to connect the communications to old metal pipes. Using compression fittings make such a connection very easy. The work process is the same as in the case of joining two pipes of polyethylene.

Reduction fittings are used in the event that it is necessary to connect two pipes of different diameters. The principle of using this connecting element is the same as that of the compression one.

We use flange connection

Very often, flange elements are used to connect HDPE pipes. This method is used when connecting large diameter pipes, as well as flanges when connecting to various valves and pumps. Such a connection can be quickly dismantled for repair and cleaning.

The flange coupling itself consists of two nodes:

1. Compression flange.
2. Mounting flange.

The first component is used for fixing the joint area from the side of the HDPE pipe - it works on the principle of compression coupling. The second node is the usual flange, with normalized dimensions. And this flange is mounted on the second part of the connection (pump inlet, metal pipe, etc.).

Video

This video shows how to connect the pipes with a compression coupling: