Flange Face Repair on ESV Valve – Local Isolation & Testing

Maintenance & Modifications
Norway, North Sea, Skarv FPSO
Project Manager
Rui Fortes
Project type
Emergency repair

Project description

For weld isolation purposes, a Twin Tyre Flexible Plug was used. This tool can navigate through bends and has a Double Block and Bleed (DBB) function for hydrocarbon system requirements. A specially designed Internal Joint Tester was manufactured to perform a local leak test with N2 and verify not only the ESV flange connection but the complete ESV after the flange face was repaired. A similar, shorter tool version was designed for the hydrostatic pressure test.  


  • More efficient and less costly than traditional methods   
  • Safer operations by use of localised leak testing tool   
  • No need to fill the entire pipeline with gas for the leak test   
  • No requirement for a full-scale hydrostatic pressure test