Weld ability of PEX and smooth control of the welding technique is a significant advantage for PEX in comparison with other materials. Homogeneous weld material satisfies all the requirements of a trumpet, material, and even substantially outweighed by the application of water electric heater.
Welded pipe, unlike pipelines using mechanical components are not divided into separate components – a pipe / PEX fitting / pipe, and a single inseparable system of homogeneous material. Thus, the use of elastodynamics sealing components such as valves, is reduced to a minimum.
When laying pipes in the ground used butt and electrofusion welding methods. PEX fittings are certified by DVGW and marked accordingly. Qualification of welders shall conform to the Status of GW 330 standards DVGW, check weld – Status of GW 331 DVGW standards for gas and PEX plumbing. This is how the construction of industrial pipelines and sewage disposal. There are also special rules DVS (German Welding Union), which define in detail indicators of welding.
The main area of application of the method of butt welding is the welding of large diameter pipes (greater than DN 200, Ø 225), as well as the laying of pipelines between settlements, due primarily costly time needed to create the weld.
The method of electrofusion welding is used in many fields. For house connections to 63 mm in diameter and branches with used almost exclusively with mortgage PEX fittings heating element. For large diameter pipe electrofusion welding is also preferred by the simple and reliable installation, the possibility of rapid preparation of PEX fittings for welding, short welding time and reducing the related costs for personnel and laying depth.
For pipes up to 710 mm PEX fittings with embedded heaters able to solve the problem of cutting into existing piping, if necessary, change the direction of the pipeline or to repair, when butt welding is impractical for technical or economic reasons.
