Induction Welding – Topic Of The Month

Induction welding equipment are only part of the offering EMMEDI provides to the Tube and Pipe market.
EMMEDI Welders are being used successfully throughout the world since the late ’60 and they’re renowned for their robust and reliable design. Our technical staff assures the highest equipment performances by carefully studying production parameters in order to grant the best in class results:

Power and working frequency are defined according to production parameters (ODs, THs, Working Speed and type of material). Hence, when austenitic and ferritic stainless steel are manufactured on the same tube mill, a special variable frequency device is supplied to provide the proper working frequency.
The inductor is customized according to the tube shape (round, square, rectangular or other shapes) and the impeder is properly sized to concentrate the magnetic field in the welding area to apply the minimum energy required.
EMMEDI welders are available with both Solid State and Vacuum Tube Technology


MOSWELD is the ultimate solid state power supply using MOSFET transistor technology
The circuit topology is current-fed inverter (CFI) with an inductance located between the DC and the HF stage, thus the inverter is naturally protected against load short circuit. The output circuit is a parallel resonance type: load and
inverter impedances are naturally matched, then no output transformer is required and therefore overall efficiency increases. Typical layout includes one power supply cabinet containing transformer, DC inductance, SCRs bridge and auxiliary circuits; a second cabinet is the welding head where the mosfet modules, capacitors and bus-bar are contained.


With a very good customers reference world-wide the High Frequency Vacuum Tube is the “Classic” Welder, appreciated by the Tube industry throughout the decades for its extremely robust design and strong reliability.
Having an overall efficiency around 70% it is provided with a patented Ripple Filter granting less than 1% of residual ripple. The peculiarity of HF Classic Welders is the extremely compact welding head, composed by a small cabinet containing the output transformer and the capacitors.