LNG FGSS Upgrade

LNG FGSS Upgrade and Commissioning Support for LNG-Powered PCTC Vessels.

In 2025, Scanunit successfully completed LNG Fuel Gas Supply System (FGSS) upgrade works on series of large LNG-powered PCTC vessels, carried out as part of scheduled 5-year dry docking activities.

Scope of Work
The work included key upgrades and maintenance activities within the FGSS:

• Replacement of existing hard-seal TCS valves with new soft-seal valves from Herose
• Overhaul and service of Vanzetti Artika type LNG fuel pumps
• Upgrade of the LNG tank sounding system, converted from ultrasonic measurement to Vega pulse radar systems, including related control system upgrades
• Service and testing of safety valves
• Calibration and testing of all FGSS sensors

All activities were performed in accordance with class and IGF Code requirements, with a strong focus on safety, reliability, and long-term operational performance.

Commissioning and Operational Support
In addition to the dry docking scope, Scanunit supported the vessels during FGSS cool-down using liquid nitrogen (LN₂) and provided assistance during LNG bunkering operations following completion of the upgrades, supporting a safe and efficient return to service.

A Challenging Project Delivered Through Collaboration
Those were by far the most challenging project Scanunit was engaged in during 2025, both in terms of technical complexity and execution under dry docking conditions. Its successful delivery was made possible through close cooperation between all involved parties.
We would also like to thank our cooperation partners Ramén Valves (Herose Swedish agent), Vanzetti Engineering, Vega, and Hydronauta for their professionalism and support throughout the project.
The project demonstrates Scanunit’s capability to support large LNG-powered vessels across the full lifecycle – from dry docking and system upgrades to commissioning, cool-down, and bunkering operations.