Induction Heat Treatment

Pipeline construction involves various pre-heating activities, for example as part of welding activities or as part of the installation of field joint coating systems. 

Onshore and offshore pipelines today involve specialist pipe configurations and pre-heat can often form a critical part of the pipeline construction. Traditional gas flame and resistance heating systems can be slow, with a wide temperature variance through the circumference of the field joint area.

The use of induction coils provides uniform, controlled heat. PIH is a specialist provider of induction coils, powered by compatible generators and inverters.

PIH provides a range of pipe pre-heat solutions, for a range of pipe parameters:

  • Induction coils with diesel generators
  • Induction coils with rotary converters
  • Induction coils with inverters
  • Weld pre-heat coils (end coils or inter-pass coils) with generators
  • Tailored solutions for combined pre-heat and coating machines (RAPTOR™)

Benefits of Induction Heat

  • No gases used (HSE)
  • Eliminates need for storage of gas bottles on the laybarge
  • Speed: Optimum cycle times
  • Controlled heat profiles 
  • Accurate, uniform heating over a controlled bandwidth: Reduced risk of damage to factory-applied coating
  • No contamination to pipe substrate

Induction Coils with Diesel Generators or Rotary Converters
Induction coils are used widely within the pipeline industry to pre-heat the pipe substrate.
PIH offers a variety of induction coils to suit a wide range of pipeline diameters and temperature requirements.

Induction coils are powered by either diesel or rotary converter generators (90 Kva-200 Kva). High-powdered inverters are also available, offering improved cycle times for pre-heating heavy-wall large-diameter field joints.

Weld Pre-Heat Coils or Inter-Pass Coils and Post-Heat-Treatment Coils
Prior to welding activities, pipe ends are pre-heated (typically 110°C-160°C). The use of induction end coils provide uniform, controlled heat. 

PIH is a specialist provider of induction end coils and inter-pass coils, which are powered by compatible generators or inverters, of varying power ratings. Induction heat end coils or inter-pass coils are designed specifically to pipeline parameters (diameter and cutback) and to meet cycle-time requirements. The equipment is lightweight and simple to operate.

Combined Pre-Heat and Coating Equipment
Combined pre-heat and coating machines are available, which offer the benefit of both the pre-heat and coating installation being carried out within the same machine and at the same station in the firing line.


PIH has developed RAPTOR combined pre-heat and coating machines for the application of Fusion Bonded Epoxy (FBE).