Induction preheating of weld area
Prosafe’s ‘Safe Concordia’ accommodation and service platform. Flameless induction heating was used to pre-heat a section of crane tower that also serves as a control room bulkhead. “© Prosafe”

Safe heating for ‘Safe Concordia’

Mobile induction heating equipment from EFD Induction was recently used to help repair a steel bulkhead on the ‘Safe Concordia’ accommodation and support platform, currently being towed to Brazil to start a contract for Petrobras.

The equipment—an EFD Induction mobile Minac 25/40—was used to pre-heat the weld area before and during the welding of a 40mm-thick steel patch onto one of the platform’s crane towers. To ensure optimal weld results, the weld area needed to be pre-heated to 80-100 °C, then maintained at that temperature throughout the entire welding process.

Such weld pre-heating is often carried out using resistance heating pads or mats. But as Jon Philpott, the EFD Induction engineer who performed the pre-heating explains, the presence of high-voltage cables near the weld area ruled out resistance heating. “Induction is not only flameless, it is also extremely fast and localized. This means induction heating results in minimal stray heating and heat soak, especially when compared to resistance heating.”

The contractor chosen to weld the patch, Whittaker Engineering, tested the EFD Induction equipment at its base outside Aberdeen, Scotland. “The offshore industry has tough safety and quality standards,” says Ken Whittaker, Whittaker Engineering’s co-founder. “EFD Induction had to first prove their solution could do the job while satisfying these requirements. Once that was achieved, the equipment, together with an EFD Induction offshore engineer, set off for Curaçao where the platform was then located. I’m more than happy with the result, and with the cooperation between us and EFD Induction.”

Built by Keppel Fels in 2005, the ‘Safe Concordia’ is a six-column, semi-submersible accommodation platform with capacity for up to 455 persons. The platform is owned by Prosafe, the world’s leading owner and operator of accommodation/ service rigs. The company owns eleven semi-submersibles and one jack-up.