The Task:
Marlin was engaged to address performance issues within the FPSO Triton sanitary vacuum waste system, which had been experiencing ongoing operational problems. The system was suffering from significant calcination build-up within the vacuum pipework, leading to inconsistent vacuum strength across the vessel and reduced toilet performance in several areas. In the most severe sections, this had already required pipe removal and manual cleaning prior to Marlin’s mobilisation.
Compounding the technical challenges, mobilisation was delayed due to adverse weather and extended permit-to-work approval times. There was also a clear operational constraint: essential accommodation and public toilets needed to remain available for personnel throughout the cleaning process.
What We Did:
Following mobilisation, Marlin engineers worked closely with the vessel’s engineering team to assess the condition of the system and agree the most effective cleaning approach. A survey of toilet vacuum intensity confirmed uneven suction across the network, consistent with internal calcinate restriction.
To carry out the descaling, we deployed our Calci-Clean units at strategic locations throughout the vessel. These are specialist chemical dosing systems designed and built in-house specifically for vacuum waste systems. These units are not commercially available and have been developed by Marlin to allow controlled acid cleaning while systems remain operational. Each unit injects a diluted acid solution into the vacuum pipework in timed cycles, breaking down calcification and internal scale in a controlled and safe manner.
Units were positioned at key branch locations across public and cabin toilets to maximise coverage. Where cabin toilets were treated, temporary connections were installed to ensure facilities remained fully operational for personnel. Where cabin toilets were involved, temporary three-way branch connections were installed, allowing occupants to continue using facilities as normal during the cleaning operation.
Chemical injection was carried out overnight, followed by multiple wash cycles to maximise scale reduction. Before demobilisation, all toilets were reinstated and functionally checked to confirm safe operation.
The Outcome:
The chemical cleaning programme resulted in a noticeable improvement in system vacuum performance, with increased suction observed following completion of the cleans. The intervention successfully reduced calcinate build-up in the treated sections of the system without disrupting essential onboard sanitation services.
While time constraints prevented full system coverage, the work provided clear evidence that further targeted cleaning would restore the vacuum system to optimal performance. Marlin therefore recommended a follow-up visit to complete the de-scaling of remaining sections, along with the introduction of a planned maintenance regime involving regular acid cleans at 12–18 month intervals. Additional recommendations were made for ejector pump overhaul and venturi cone replacement to support long-term system reliability.
