Cases of scrubber corrosion surface less than six months after installation
THERE have been cases reported of corrosion to scrubber system pipeworks and discharge outlets less than six months after installation, resulting in costly replacement works, experts told Lloyd's List
THERE have been cases reported of corrosion to scrubber system pipeworks and discharge outlets less than six months after installation, resulting in costly replacement works, experts told Lloyd's List.
Several major classification societies are tracking an increase in scrubber-related issues and while no class society is prepared to reveal exact numbers, experts within societies have confirmed there have been several instances of corrosion related to quality issues traced back to the installation.
Scrubber manufacturers, including Wartsila Scrubber, and owners who have installed systems have told Lloyd's List there are no issues with systems, many of which have operational experience dating back a decade.
However, the recent acceleration of scrubber installations to meet the International Maritime Organization's 2020 sulphur cap deadline of January 2020 has led to a significant increase in corroded pipework repairs handled by companies being called in to fix problems.
'Corroded scrubber pipework and discharge outlets is a serious problem that is not widely understood by people installing these systems, and we're seeing more of it,' chief executive Boud Van Rompay of Hydrex, an underwater repair and corrosion specialist, was quoted as saying.
'Piping is being eaten by corrosion because it is handling acidic residue. The problems we are seeing are quite astonishing and the speed of the corrosion is like nothing I've seen before,' he said.
According to marine engineering expert Gary Rawlings at the Bureau Veritas consultancy TMC Marine, corrosion occurs because of the acidic nature of the residue being processed, but the problem is not with the manufacturing of the scrubber itself, rather it is the ancillary piping and pump mechanisms that can cause issues.
Corrosion can happen if pipes are not cleaned properly prior to coating, or if the coating has not been properly applied, or if damage occurred, for example the equipment was bumped during the installation, he said at a conference during London International Shipping Week.
'Materials and coating choices are critical to avoid issues,' he said, but pointed out that expensive corrosive-resistant materials are becoming harder to source and some manufacturers have stopped taking new orders as lead times can be four months or longer.
'One of the key problems is that there is no reliable way to predict the speed of the corrosion and that can result in safety issues,' said Mr Van Rompay.
Mounting delays at shipyards to retrofit scrubbers on vessels are already causing costly delays for owners scrambling to meet the IMO's deadline for sulphur emission compliance. The average time for installation is currently running at 40 days depending on the type of ship.
Despite the concern from corrosion experts, owners who have already installed systems report no significant downtime due to repairs and one major shipowner has cautioned that much of the anti-scrubber rhetoric being widely spread around the industry can be tracked back to stakeholders with a vested interested in discrediting scrubber systems.
When Lloyd's List approached the Clean Shipping Alliance, a lobby group established in 2018 by leading shipping companies that have invested in scrubber technology ahead of the 0.5 per cent sulphur cap, for a comment, a spokesman pointed Lloyd's List to DFDS - a company that reports almost no downtime due to its scrubbers.