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Ice Pigging Refreshes Diesel Fuel System
In early 2024, Nivalis were approached by a maritime contractor who was experiencing issues with contaminate build-up in one of their ship's diesel fuel systems.
We worked closely with the contractor to develop a process to isolate contaminated pipework from the system and systematically clean sections using our innovative, cost-effective Ice Pigging technology.
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Posted on: 28th Aug 2024
When contacted about the build-up of contamination, biofilm and other debris causing reliability issues in a ship's fuel system, we knew that our effective Ice Pigging cleaning technology would be perfect for tackling the issue.
As with all projects, our initial discussions with the contractor (who cannot be named for confidentiality purposes) were focused on fact finding to ascertain what the requirements of the client were. Our team of experienced engineers followed this up with a site visit to fully assess the issue, determine what was required in terms of cleaning and to carry out some testing.
We worked closely with the contractor to develop a low-risk approach to carrying out Ice Pigging on site, forming risk assessments and producing documentation detailing how Ice Pigging would be carried out so everyone involved knew what was happening at each stage of the process.
Why did the pipelines need cleaning?
As with most modern ship fuel systems, once the bio contamination has started and spread throughout the whole system, it is very tricky to determine the root cause. This case was no different so the cause is unknown, however that does not stop us being able to clean the pipes effectively.
How do you clean a ship fuel system?
With all the relevant paperwork in place we were able to get stuck in to our robust cleaning procedure as follows:
- Isolate contaminated pipework section from the rest of the system
- Carry out flow integrity testing (flow direction and pressure testing)
- Injection of the Ice Pig
- Inline analysis of flow at the outlet and samples taken
- Water flush
- Blow down of pipework
- Reinstatement of system with diesel fuel
Working through the system in sections minimised risk and reduced downtime for the overall system. We repeated this process for all sections of the pipework which were showing high levels of contaminate removal.

How long did it take to clean the fuel system?
Over a period of four weeks nearly 40 Ice Pigging operations were undertaken. This work could have been completed in a shorter timeframe but our experienced team had to be flexible to fit in around other critical activities at the dockyard.
We are very used to working in busy locations, often with tricky logistics to navigate and we pride ourselves on being professional and flexible at all times.
How do you monitor the effectiveness of Ice Pigging?
To monitor effectiveness of the cleaning process, a number of points in the pipework system were identified as inspection points. At these points visual inspections were taken before and after the Ice Pigging process. Our engineers also took samples at the outlet of each run for visual inspection and lab testing.
Final ice samples were verified by the contractors appointed quality representative for sign off to ensure everyone was happy with the end result.
Did Ice Pigging successfully clean the fuel pipes?
Yes! All final samples on each section of the pipeline were free of contamination after cleaning - this was also confirmed by the client's quality representative.
All inspection points on the system were visually inspected and verified as clean, and after the Ice Pigging process was completed, the system was flushed with potable water, drained and then our engineers helped the team with a clean diesel flush.
The client was happy that the entire Ice Pigging process was completed quickly and efficiently with minimal impact on other critical work happening in the dockyard at the same time.
Implementing Ice Pigging has meant that the ships fuel system has improved significantly in terms of cleanliness. This was confirmed by the engine OEM stating that prior to carrying out our Ice Pigging process, the fuel pumps were constantly being damaged (despite filters on the system), however since Ice Pigging, the fuel pump reliability has greatly improved. This means the team can enjoy reduced maintenance pressures and as a result reduced system “downtime”.
We are very pleased with the results of this project and have recommended that the contractor considers carrying out Ice Pigging as a regular service to prevent contamination build-up reoccurring.
If you would like any more details about this project or would like more information about how Ice Pigging can help you, please get in touch.