Since the wire is more than half of its volume is in the PEX, the thermal energy during welding gradually allocated to the surrounding material. With this temperature wire is guaranteed at the required temperature welding. Due to melting of the tube directly into the beginning of the welding process is the thermal expansion of the pipe material in contact with the clutch. The result is a very rapid filling of the gap between the PEX fittings and pipes, because coupling increases in the direction of “inside” and pipe – “outside”. Compared with PEX fittings with the closed front coil welding is not smooth, but undulating. As a result, the contact area increases significantly.
If, however, follow the manufacturer that the PEX fitting must be removed from the package directly to the welding joints formed on the surface oxide layer, the wave-front welding it will be destroyed and will have no effect on the welding process. Pollution, settled on the clutch at the construction site, to protect against that actually serves as a packaging must be removed for cleaning means in accordance DVGWP 603.
The coil is located in PEX (Fig. 2) so that the extraction of revolutions without an instrument (eg, screwdrivers), ie unauthorized access, completely excluded. Damage or stretching of turns open coil while inserting tubes removed.
This is confirmed by practice: thirty years of operation at construction sites of complaints about damage to the heating coil when inserting the pipe had been filed.
Conversely, when an open heating coil users can easily control its position. This aspect can not be underestimated, if we recall that the thickness of the layer of PEX with a closed coil can be determined.
About the possible use of PEX fittings FRIALEN ® with an open coil systems of industrial pipes were long-term tests in very acidic and very alkaline environments. Tests have always been successful and leading firms in the chemical industry for decades mounted PEX fittings FRIALEN ®.
Labeling
By marking the PEX fittings, there are certain rules. Basic parameters such as the manufacturer, the nominal diameter, material designation, SDR and data relating to manufacture of the product should be readability for a long time. Data relating to installation on site, such as welding parameters and reverse tracking range of the SDR pipe and the necessary cooling time after welding may be indicated on individual labels in the form of a barcode. All data should be readability with PEX fitting
