Skip to main content



Thursday, May 27, 2021 

DNV has issued a Type Approval Design Certificate for Alfa Lavalís PureBallast 3 Ex deckhouse ballast water management systems (BWMS), which the company hails as a major achievement, representing the first design approval for the installation of ballast water treatment systems on the weather deck, leading to time and money saved in the final approval process.

Placing BWMS in a deck-mounted enclosure is necessary on most modern tankers, which lack a pump room or other suitable internal space. While the system type approval applies to the system itself, both the enclosure and the installation within it must also be approved by a classification society. The DNV Type Approval Design Certificate means PureBallast 3 Ex deckhouse deliveries will have this approval in advance.

Head of Alfa Laval PureBallast Peter Sahlén said: “Alfa Laval quickly recognised the importance of having a standardised and purpose-built solution for installing PureBallast 3 Ex on deck. Likewise, DNV recognised that this would require a unique approach to the approval – given that the solution falls outside traditional class definitions. Working together, we’ve achieved a design approval that encompasses the reinforcements, insulation, ventilation and other elements that protect ballast water treatment system performance and lifetime.”

Endre Lajord, Project Manager, DNV, said: “When dealing with a new type of installation that may not fit within existing class definitions, it is essential to make sure that the solution conforms to the same rigorous standards. Installing ballast water treatment systems on the weather deck is a new area, and we were very pleased that Alfa Laval chose to work with us on this design approval. As the world’s leading class, we are always ready to help forward-looking companies like Alfa Laval to deliver unique solutions. We do this by giving their customers the necessary trust and confidence through the DNV class approval process.”

In practice, the design approval for PureBallast 3 Ex deckhouse solutions will reduce the time and effort needed from system integrators – and the implications for shipowners. For the final onboard approval, only the mounting of the enclosure on deck and its interconnections with the vessel will need to be evaluated by the classification society.

“Having class approval for our design specifications makes the deckhouse essentially a plug-and-play solution for installation on the weather deck,” said Sahlén.

Alfa Laval’s approved design includes the deckhouse enclosure itself, as well as the system’s internal installation on fixed rails and all of the internal piping and electrical connections. Its specifications go beyond those of standard containers, which lack the protective features and longevity needed to ensure performance over the vessel lifetime.

“Our deckhouse design ensures conditions that keep PureBallast 3 Ex within its design limits, from the interior climate to factors like wind and wave loads,” said Sahlén. “It may be a containerised solution, but it’s by no means a standard container.”

Reader Comments (0)

There are currently no comments on this article. Why not be the first and leave your thoughts below.

Leave Your Comment

Please keep your comment on topic, any inappropriate comments may be removed.

Return to index