PE pipes have a lot of advantages: they are not susceptible to corrosion, chemically resistant, do not promote deposits on the inner surface of the pipe, have long operating life and offer sustainability. The major advantage of PE is in its rheological properties, it can be welded well due to a wide temperature interval of viscous-flow state (over 70 °С) and a low molten viscosity.
There are two major methods of PE pipes joining – using electrofusion fittings and butt fusion welding.
Electrofusion welding is more expensive than butt fusion. This is due to the need to use relatively expensive fittings with incorporated heating elements. However, these fittings have their own advantages. If welding of PE pipe is carried out in confined spaces where butt fusion welding machine can’t fit, then electrofusion welding machine that does not require a lot of space becomes the only alternative.
Electrofusion welding is essentially an operation where you put an electrofusion fitting on the joint that needs to be welded, and a using special device apply the voltage to the heating element. The latter melts contacting surfaces of coupling and pipe forming a pressure tight joint. Compact and light electrofusion welding machines are easy to use and consume very little power.
This is the most universal and popular method for creating joints. The strength of the butt joints is not inferior to the strength of the adjacent sections, and the welded pipeline is no different from the pipe itself in terms of integrity, flexibility and reliability.
The joining is carried out in the following sequence:
When doing quality control a special attention is paid to the shape and size of the bead (materials buildup around the joint). Its geometrical parameters must comply with the certain requirements. The quality of work depends both on the right choice of welding equipment and the competency of welding operator.