Back-Gas Njord A Offshore HU 2022

Maintenance & Modifications
Norway, Norwegian Continental Shelf
Product manager
Peter Bjørnsen
Project type

Project description

For the Njord A Hook-up in 2022, 4 Tie-in spools were installed. Due to pipeline configuration, each hook-up spool had 2 Golden Welds.  

Due to subsea-specified regulations, after the spools had been installed and welded, the lower Subsea riser interface welds must be verified by gauging and inspection.  


Due to the available design and time aspects, IK Topside’s Twin-Tyre Flexible Plugs were chosen for these operations since the tools were readily available and required only some slight modifications. These tools are usually used for weld isolation purposes on hydrocarbon process systems, and they provide two barriers suitable for localized pipe/spool section isolation and verification.  


Once the pipe/spool section has been isolated, backing gas is purged into the annulus and carefully monitored during welding operations. This provides the required atmosphere when welding with materials such as 6MO and Super Duplex.  


The lightweight Twin Tyre Flexible Plug can navigate through pipe bends and has the necessary structure to accommodate specialized modifications, such as those used in these specific successful operations.  

“I just wanted to inform you that your technicians get a lot of praise from the offshore organization. They are constantly mentioned in meetings as having done a great job and the equipment working as intended.”

– Client