Seam Annealers

Thermatool’s globally proven and reliable Seam Annealing equipment is uniquely designed to effectively Post Weld Heat Treat (PWHT) HF welded tube and pipe across a wide range of product diameters, wall thicknesses and material chemistries. Providing successful and repeatable quality control and process repeatability, Thermatool Seam Annealers are available with SmartAnneal™ closed loop temperature control and real-time process monitoring. Powered by the metal industry’s most widely used and preferred VIP™ Series Power Supplies, Thermatool Seam Annealers offer the most comprehensive automation and control package (including recipe recall) available to mill operators today – while ensuring the most efficient delivery of power to the tube or pipe.

In addition to standard tube and pipe applications, Thermatool™ Seam Annealers can be fit to spiral products, engineered structural sections, and custom tubular profiles.

Inductor Design
The method of introducing the magnetic fields to the pipe is achieved through the inductor design. Thermatool uses two specially designed and proven options, a traditional or “V” shaped inductor, that can be used for focusing the magnetic fields to the pipe heat affected zone or “HAZ” for enhanced delivery and maximized efficiency. Thermatool engineers developed this proven design that is specially shaped to concentrate the fields into the pipe and minimize overheating of the area around the HAZ. Concentrating the fields to the proper area results in a more efficient power transfer. Due to the concentrated fields, the magnetic attraction between pipe and tube can be significantly reduced and the required power is more effectively applied.

Speed Power Control
Thermatool Seam Annealers offer selectable Speed Power Control (SPC). The SPC feature, automatically adjusts each annealer’s output power with changes in mill speed. This ensures the correct power output is maintained during mill operations, enabling increased yield and reduced scrap. SPC also engages the annealers automatically with the mill run signal.

VIP™ Power Supplies
Thermatool shares the VIP design with the Inductotherm Group companies with an installed base of over 30,000 of these power supplies worldwide. These same power supply designs are used in various industries such as melting, heat treating, vacuum refining, full body tube heating as well as seam annealing. This power supply design is very modular and ranges in sizes from 50 kW to over 38 MW, 0.2 kHz to 10 kHz applications. They feature intelligent microprocessor-based digital controls and are engineered to operate at a constant high-power factor regardless of power level, while generating low harmonics and voltage distortion. Harmonic and voltage distortion is further reduced in larger units by designing the equipment to accept 6, 12, or even 24 input phases.


Inductotherm Group Italy S.r.l.

Via Luigi Einaudi 29 10024 Moncalieri (TO) Italy

  • Phone: +39 011 0252155
  • Fax: +39 011 0201852


  • Greater than 92% efficiency/0.95 input power factor for all conditions.
  • Mill-mounted carriage assembly for precise positioning of the inductor.
  • Optional horizontal slide track available.
  • Quick-lift mechanism to rapidly raise the inductor from the pipe, away from any open seam conditions.
  • Automated seam-tracking capability option.
  • Independent free-moving carriages for simple offline maintenance.
  • Single and dual inductor configurations available to meet a wide variety of applications.
  • Proprietary “V” inductor geometry for increased efficiency and focused heating.
  • Real time feedback via PLC control.
  • Closed-loop temperature control with set-point, and minimum and maximum temperature limits.
  • Selectable Speed Power Control (SPC).

Tech Specs

Power output: 250kW to 1000kW
Operating frequency: 0.5kHz, 1kHz, 3kHz, or 6kHz as required