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Ice Pigging technology gets rid of black contamination

In October 2023 a client contacted us to discuss the use of Ice Pigging technology for the removal of black contamination which had been detected in the internal bore of sea water nasal spray supply lines.

For confidentiality reasons we are unable to mention company or product names, but we can give details on how we successfully approached and carried out this job for our client.

Ice Pigging technology gets rid of black contamination


Posted on: 7th Feb 2024

Why did the pipelines need cleaning?

In our initial conversations with the client we learnt that they did not know the origins of the contamination, but that it may relate to the break down of elastomers in the system or biofilm, or a combination of the two.

Whichever the cause, we discussed with the client how our Nivalis Ice Pigging technology could be used to clean the pipe lines and we recommended sodium chloride as the Freezing Point Depressant (FPD) additive to be used.

Why was sodium chloride used as the FPD?

It's important to highlight that the Nivalis Ice Pigging technology allows for the utilisation of various Freezing Point Depressants to form ice. In the context of biofilm remediation projects, certain FPDs, such as sodium hydroxide, contribute to inhibiting bacteria and enhance the overall effectiveness of the Ice Pigging and biofilm remediation process, however the use of sodium hydroxide as an FPD is ultimately the client's decision, taking into consideration safety risks specific to their application. Most acids and many alkalis are suitable as FPDs.

In this case sodium chloride was chosen as the Freezing Point Depressant (FPD) - “the additive” - to allow ice formation using the NIV500 system. A 5% sodium chloride solution (brine) will serve as the FPD.

Ice Pigging the pipework

Once we had agreed a process with the client, Ice Pigging was carried out in January 2024.

Nivalis successfully executed all Ice Pigging activities that were agreed with the client. In total, 38 Ice Pigging operations were successfully undertaken on 16 different flow paths, all work on the production line was completed within a period of 30 hours (duration from line being stopped to completion of Ice Pigging) across 4 working days which included:

  • Day 1, Nivalis equipment delivery and set up, start of ice production (no production impact).
  • Day 2, Ice Pigging activities (production stopped).
  • Day 3, Ice Pigging activities & completion followed by equipment pack down (production stopped followed by restart).
  • Day 4, wrap up meeting with client followed by Nivalis equipment collection (no impact on production).

Downtime for the production line was expertly kept to a minimum.

Maintaining high quality standards while Ice Pigging

To ensure that our Ice Pigging procedures met the strict quality standards of the client our team of engineers incorporated additional gowning and an aseptic approach during connections to the customer's system. This meticulous approach aimed to minimise the risk of further contamination.

To ensure compliance with the client's documentation and test procedures, visual inspections were conducted by the client in the specific locations. Visual confirmation through the inspections revealed the successful removal of contaminant from the internal surfaces of the pipes. For example, on several of the operations outlets, samples were discoloured (grey in colour) indicating that black residue had been removed from the line. At the end of every pass on each section of pipework, ice samples were verified by the client's appointed quality representative to ensure that the process was meeting their high-quality standards.

What were the outcomes of the Ice Pigging work?

  • All final run samples on each section were identified to be free of contamination by a client quality representative.
  • Inspection points on the lines were also visually inspected and swabbed. All points were verified as clean.
  • After Ice Pigging the system was flushed with de-ionised water until any residual brine solution was removed (as determined by conductivity measurement at the line outlet with established limit of <15μS/cm).

All 16 Ice Pigged flow paths successfully passed all the criteria.

Ongoing Ice Pigging support

Ice Pigging is often used as a preventative measure to de-risk the potential for system contamination, at the same time improving production/process resilience. It was recommended to the client that Ice Pigging be carried out as a regular service undertaken on a routine basis. Based on understanding of the system, a biannual service was recommended to control contamination within the system.

It was highlighted that by using Ice Pigging as a preventative maintenance technique to physically clean the pipe systems, this may enable the current system sterilisation process interval to be increased from 3 days to a longer period (7-10 days), improving overall efficiency of the production line.

You can read the full case study for this project here, or if you'd like more information on Ice Pigging and our services please get in touch and we'd be happy to help.

Find out how Ice Pigging could work for you

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