Wärtsilä Underwater Services’ diver performing a scrubber discharge pipe restore on a container vessel.
Wärtsilä and A.P. Moller – Maersk have developed a way for stopping corrosion in exhaust-gas scrubber discharge pipes. The everlasting in-pipe answer is designed to resolve corrosion issues related to open-loop scrubber washwater discharge.
The majority of the estimated 5,000 scrubber programs put in the world over fleet are of open-loop configuration. With this method, seawater is used to clean SOx from the exhaust gasoline, with the used water then being discharged again to the ocean after cleansing.
Under IMO Guidelines, the washwater from exhaust gasoline cleansing programs, or scrubbers, ought to have a pH of a minimum of 6.5. However, in actuality the pH of scrubber washwater is often acidic, previous to being diluted by seawater. This creates the danger of structural corrosion to the discharge pipes.
The threat of scrubber discharge pipe corrosion is especially excessive for pipes product of delicate metal. In some circumstances, if the discharge pipes are inadequately protected, extreme corrosion can harm the encompassing delicate metal hull plates, leading to water ingress.
The new “pipe-in-pipe” answer permits for the unique overboard pipe to stay in situ whereas a brand new glass bolstered epoxy (GRE) pipe is inserted into it. No steel chopping or welding is critical. An SMO stainless-steel sleeve is inserted between the brand new GRE pipe and the present metal pipe. An adhesive completely secures the GRE pipe in place. Since this “pipe-in-pipe” answer has a small impression on the interior diameter of the pipe, it’s best suited to overboard pipes with a diameter higher than 300 mm.
“This is a long-term solution that can be planned for at any time, even if corrosion has not yet occurred,” says William Winters, managing director of Wärtsilä Underwater Services. “The component pipes can be prepared and stored either on board or at an engineering facility ready for fitting either during a scheduled drydocking or port-call or, if necessary, while afloat and in operation using a cofferdam at a convenient time and location.”
“This in-operation repair offers substantial overall savings to the ship owner and allows the vessel to stay in service,” provides Winters.
“We have noted corrosion incidents occurring on some scrubber equipped vessels and wanted to be proactive in solving the problem,” says Jorn Kahle, Senior Lead Specialist, Maersk. “Additionally, taking a vessel out of service is extremely costly. One of the key driving forces for development of this pipe-in-pipe concept with Wärtsilä Underwater Services is to minimize these disruptions and costs. We are happy to offer this unique cost-efficient service to any vessel with any make of scrubber”.
Installations of the patented answer and licensed know-how will probably be carried out by Wärtsilä Underwater Services. In most circumstances, the restore will probably be accomplished in lower than two days, which might keep away from the ship having to go off rent. Considerable time and value financial savings in comparison with different restore options have already been demonstrated.
The Wärtsilä/Maersk answer is meant for long-term safety. It reduces problems related to welding work required on pipes and typically hull plates, notably in underwater restore conditions.
