The handling and assembly of polyethylene (PE) pipes require some essential precautions so that the conductions keep in perfect conditions before the installation. If they are damaged due to the bad storage or if they have some damages, this affects negatively to their characteristics and durability, however, if it is well done the rest of the installation works.

Tubos de polietileno

Therefore, it is very important to raise awareness the importance of fulfilling certain common normative of these materials.

How are the PE pipes stored?

Regarding to the storage, the PE pipes should never be in contact with solvents, fuels, paints and other components. They also should be far from other stem or hot water pipes, especially if they reach high temperatures.

 Regarding to the sun, we can differentiate how they are stored depending on the colour of the PE pipe:

  • The black colour pipes can be stored indoor or outdoor, as they are protected against ultraviolet (UV) rays due to the addition of carbon black.
  • The other ones of another colour should no stay more than six months outdoor before being buried, exposed to the ultraviolet rays and with no protection.
  • The orange and yellow ones will be protected with a plastic film during their storage and supply.

The pipes can be stored both in bundles, fixed with wooden clamps, or on horizontal shelves, always with the support they need to avoid deformations. Another option is to store them horizontally, one on top of the other.

How are the PE pipes transported and handled?

During the handling, the pipes should never be dragged over the floor, as they could be damaged by the stones, rough gravel or sharp edges. In case of scratches, it is only admitted if the depth doesn’t surpass the 10 % of the thickness in pipes for water and the 5% in pipes for gas.

For its transportation, the pipes will be placed on the vehicle without using metallic wires or chains. If we out them vertically, we will be avoided to place some rolls one on the top of the other and neither it could be placed other loads on them, so that there are no deformations.

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In road junctions it is advisable, to avoid deformations, to tube the pipe. This must be like a snake in the bed of the trench so that the expansions and tensions produced by the water hammer don’t affect the joins.

The PE pipes are usually delivered in rolls up to a diameter of 110 millimetres and the rest in bars of 6 or 13 metres long, grouped in bundles or pallets. If when the pipes arrive to the place where they must be installed the trench hasn’t been opened yet, these will have to be placed on the opposite side they are going to be installed on the ground produced by the excavation of the trench.

While the pipes of small diameter, delivered in rolls, will be extended tangentially, the ones of higher diameter will be horizontally extended.

The technique consists in tiding the end of the external pipe to a fixed point and stretching carefully the end of the internal pipe of the roll, to which it has been tied a string of some 5 metres. The PE pipes are flexible, so they are usually joined outside the trench.

What must be taken into account in the installation of a pipe in a trench?

The bend radius will be different according to the type of material and the nominal pressure of the pipe. To avoid impacts on the joins due the tensions which generate the changes of temperature and water hammers, the pipe should be snaked at the bottom of the trench or when it is on the surface.

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If the pipe has to go through a wall or something similar, a cable gland will be installed so that the pipe doesn’t come into direct contact with it. It is important that the slope of the bed of the trench is uniform and be free of any sharp element, stones, etc.

In the highest points, besides, it must be used suction pads, as the air accumulates in the highest parts of the conductions. So in this way, the water circulation flows as the air goes out.