Defence Sector Case Study

An example of when Ice Pigging is used in the Maritime sector

In June 2020, inspections of a fuel system on board an active warship identified a small amount of contamination. Filter meshes in the system picked up particulate from the fuel. Camera inspections of the pipe internal bore indicated that material had contaminated the pipes. Quality of fuel on board this kind of asset is paramount to operational performance and safety, so the complicated onboard system of pipework and tanks required a deep clean as part of the remediation process.

In this case the customer was a multinational defence contractor responsible for the upkeep of major assets.

The customer is also a leading provider of critical, complex engineering services which support national defence, save lives, and protect communities. The customer works hand in hand with the Navy on key asset management activities, which include deep maintenance, in-service support and life extension of surface warships, upgrading, overhauling and managing equipment and systems and managing naval bases.

Testing Ice Pigging to clean ship pipework

The end user's requirements increasingly demand innovation which led the customer to look into Ice Pigging as a highly efficient pipe cleaning technology for applications on maritime systems.

Following successful demonstrations in late 2019, testing discrete sections of pipework, demonstrations were carried out on an asset undergoing refit.

Demonstrations not only proved the effectiveness of Ice Pigging, but also the ability to deliver Ice Pigging within the challenging dockyard environment.

Although Ice Pigging was still a relatively new technology for the customer, the need to urgently remediate a challenging system on board an active warship presented an opportunity to utilise Ice Pigging to full effect. With only a few weeks’ notice, the Nivalis team were able to deploy a containerised NIV500 Ice Pigging system to the Dockyard with a team of Ice Pigging process engineers. The team completed a full clean of the on-board system pipework in collaboration with the customer and end user.

Technical details for using Ice Pigging in this Maritime sector example

For the particular fuel system, cleaning citric acid at 8-10% was selected as the freezing point depressant (the additive prevents the ice from forming a solid block enabling it to have unique fluid like properties). This was in preference to sodium chloride used previously on ships fuel systems. Ice was produced and delivered by a hygienic NIV500 Ice Pigging system capable of producing food grade ice to a high cleanliness standard.

Since the NIV500 is designed to be utilised indoors in factory environments, the NIVALIS team adapted the machine to fit in a specially engineered 20' shipping container so that the system could be a position on the dockside transferring ice and flush water onboard the vessel via a hose. In total, 6 flow paths were cleaned over three days. Cleaning was achieved in a single pass on each path.

The ice was driven through the pipework using a pressurised water supply, also controlled from the containerised system. Water was purged from the lines using compressed air before drying and final flushing with fuel.

Repeat visual pipe inspections and filter analysis of fuel from the system verified that the cleaning was successful. The speed and efficiency of Ice Pigging allowed the overall remediation process to be expedited enabling to the ship to return to service in a fully operational state.

Summary of Nivalis Ice Pigging

1. Completed Ice Pigging operation in line with customer process standards.
2. Ice delivered in the dockyard to pipework onboard an active warship.
3. All systems cleaned in a single pass with 200-300 kg of ice.
4. All pipework cleaned in 3 days.