HDPE pipe: do-it-yourself installation, installation features and instructions

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

PE pipes are versatile due to the excellent characteristics of the material. Increasingly, HDPE pipes are being used in everyday life. Installation can be done by hand, if everything is done according to the rules. This does not require special qualifications.

Material specifications

High demand for HDPE pipes is caused by the high quality of the material:

• temperature range - from -50⁰С to +60^0С;
• resistance to acidic and alkaline environments;
• high elasticity and strength;
• low thermal conductivity;
• polyethylene is not a conductor of electricity.

Use of pipes

In the house or in the country, HDPE pipes are made:

• sewerage and drainage;
• plumbing;
• gas supply to the house;
• cable channel for electrical wiring.

Pipe selection

For drinking water pipes, pipes with a diameter of not more than 60 mm with a wall thickness of 4 mm are purchased. They must be designed for the working pressure of the liquid in the system not lower than 1 MPa. The advantage is the absence of corrosion andthe taste of metal in the water. If you want to equip hot water supply, you need to know that at a temperature of 80⁰C, polyethylene softens, and with a further increase it begins to melt. In this regard, you should choose a brand not lower than PE80. For hot water pipes can also be marked PE-RT or PN20, they can withstand temperatures up to 110^{0C. For domestic conditions, this is quite enough.}

It is necessary to distinguish between pipes for water supply and non-pressure. For normal operating conditions of the water supply, bays 25 m long are taken with a wall thickness of at least 2 mm. If the main line operates under good pressure and has a diameter of more than 25 mm, then an inch pipe is taken as a branch. In any case, the outlet must be smaller than the general water supply.

Methods for connecting HDPE pipes

Before installation, you should choose a connection method, which can be as follows:

1. One-piece - electrofusion or butt welding. The connection is obtained with the same strength as the pipe itself.
2. Detachable method - socket, compression and flange connection. Such piping systems are easily assembled and dismantled, it is possible to repair or install in hard-to-reach places. Connections are made with fittings.

The connection method is selected depending on the following factors:

• pipe diameters;
• operating type: non-pressure, pressure, cabling;
• use of reinforcement from different materials and with different diameters;
• site accessibility;
• availability of weldingequipment.

Welded and flanged connections are the most durable. Threaded coupling with seal is unstable to loads. Installation of HDPE pipe for water supply with compression fittings is usually done in home gardens for plant watering systems.

The weakest connections are flared. They are used only in non-pressure pipelines, except when the connection is made welded.

Compression fittings for HDPE pipes: installation

For HDPE pipes, plastic fittings are predominantly used, but there are also more durable options made of steel, cast iron, copper and brass. They differ in design and can be welded, threaded, with a press connection. For plastic pipes, compression fittings are predominantly used, where fixation is made by a clamping split ring made of hard plastic with notches, and sealing is by tightening the sealing rings.

Like other connecting devices, there are several types of compression fittings:

• coupling - for connecting pipes of equal diameter and direction;
• transition - for fastening the ends of pipes, the diameters of which are different (transition "metal-polyethylene" is possible);
• retraction, angle - rotate the structure by 45-1200;
• tee, cross - to create branches;
• fitting - a device for connecting a pipe with a hose;
• cap - for sealing pipe ends.

Before laying the water pipe, first of all, you need to draw a diagram of it with all fittings and valves. The expanded pipe tends to twist, so it is fastened with clamps or pressed in a straightened state for 2 days.

If an HDPE pipe is chosen for installation, installation is often done with compression fittings.

1. The pipe is cut to size with a special tool. You can use a regular hacksaw for metal, but the end is made even and cleared of burrs.
2. The hole is aligned with the calibrator, since its oval shape is not allowed. An external chamfer is made at the end.
3. The fitting body is carefully connected to the pipe so as not to damage the rubber seals. Landing will be easier if the joint is moistened with water.
4. The union nut is tightened by hand. A wrench can be applied to provide the required connection density.
5. The procedure is repeated for the second pipe.

Compression fittings are convenient to use when installing HDPE pipes in the country. The system is easy to assemble on site in spring and dismantle in autumn.

Detachable connections in hard-to-reach places are not made. It is convenient to use electric couplings with a built-in heater. 2 pipes are connected by a fitting, after which its heating is turned on and welding takes place to form an integral assembly. The price of the device is high, but the method is effective and often used.

Despite the possibility of disassembly, compression fittings must be replacedrubber seals when reinstalling. This will ensure high reliability of the design.

Flange connections

When HDPE pipe is installed, installation for diameter over 40mm is preferably done with metal flanges. To do this, the edges of the pipes are cut with a pipe cutter at a right angle according to the finished markings. Then polyethylene bushings with sides are welded to them, and metal flanges are installed on them. Another method is to mount a compression flange on the pipe to fix the smooth polymer joint. Then a regular flange is installed, which is fastened with studs and bolts with a similar part installed on the end of the steel pipe.

Flange connection allows you to connect valves, regulators, valves and pipes to each other.

Welded joints

Just like metal products, HDPE pipe can be welded. Do-it-yourself installation is carried out using special equipment with electric heating of the joints.

1. The joints are being cleaned and the welding equipment is being prepared.
2. Set welding parameters.
3. The pipes are fixed in the clamps of the welding machine and centered. The ends are machined.
4. Heaters are installed between the pipes, with the help of which the edges are melted.
5. The ends are brought together under pressure, which is maintained until cool.
6. Pipes are removed from clamps.

The cost of installing HDPE pipes by welding depends on the diameter, but up to a value of 63 mm the priceusually the same and is about 200 rubles. for the joint.

When using an electric clutch, the installation costs are the same as for butt welding, but it has a higher price. As a result, the cost price is higher.

Hydraulic testing

The performance of the assembled water pipe is checked by filling it with water for 2 hours. The system is then pressurized and maintained for 30 minutes. The pipeline is inspected for leaks.

During operation, the state of the system is constantly monitored. When properly assembled, it will function for a long time.

Errors when installing HDPE pipes

1. It is important to take into account the linear expansion of pipes due to temperature. If you forget about it, the voltage inside the pipes exceeds the norm, which reduces their life.
2. Too much spacing between fixtures causes sagging in the pipeline, leading to premature failure.
3. Pipes are only cemented with insulation.
4. So that condensation does not form on the surface, pipelines for supplying warm or cold water are insulated.
5. During installation, the fitting is disassembled so that the pipes go inside as far as they will go. If you do not unscrew the nut completely, and then forcefully push the pipe into the connector, it may not go deep enough. When do-it-yourself installation of HDPE pipes is done in the country for the irrigation system, leaks are not so dangerous, but this is unacceptable for home plumbing. Regardless of the consequences in both cases, it is necessary to createtight connection.
6. Overtightening the adapters will cause them to break or the gaskets to slip out of their mounting locations.

Conclusion

When HDPE pipe is installed, the installation is done mainly by welding or compression fittings. If properly installed, the connections will be airtight and strong for many years.