The Alfa Laval Moatti 290 filter for hydraulic control oil (HCO) has been approved by MAN Diesel & Turbo on its modern two-stroke engines. The decision follows validation tests aboard three Stena Bulk IMOIIMAX vessels, where the HCO filter’s performance has exceeded all expectations.
The filter is a high-performance solution, suited to the new generation of MAN Diesel &Turbo two-stroke engines, in which hydraulic control systems have replaced traditional camshafts. The valves of these systems are actuated by a small flow of lubricant oil, which must be very finely filtered without creating additional pressure drop. The new filter achieves this using Alfa Laval Atrium technology, which provides a tremendous increase in filtering surface within a compact space.
“We are extremely proud to have the Alfa Laval Moatti 290 filter validated for use with HCO systems,” commented Herve Gourdon, Business Manager, Filters at Alfa Laval. “This is the culmination of 10 years of intense cooperation, development and testing.”
Alfa Laval began discussing the filter with MAN Diesel & Turbo in 2008, when the engine manufacturer started its transition from camshafts to hydraulic control systems. The HCO filtration required by the engine design demanded an entirely new filter technology. Alfa Laval’s prototype HCO filter, presented in 2014, spent over 24 000 hrs in concept testing aboard the Suezmax crude oil tanker Stena Suède.
The filter is built to the most recent MAN Diesel & Turbo recommendations, which require both an automatic filter and a redundant filter with high enough efficiency to retain particles of 6 µm and below. These are incorporated into the same frame, with a specially designed changeover valve to prevent any leakage during maintenance.
The redundant filter, which is manually cleanable, can be used not only during maintenance, but also for initial oil cleaning or when new oil is added into the system. It is not used, however, to clean the small flow of oil that provides continuous backflushing. Instead, this flow is cleaned in a diversion chamber before it is returned to the sump.
The continuous backflushing of the filter is driven by the pressure of the oil itself. This means no electricity or air supply is needed, which is one of several ways the filter simplifies installation. Because backflushing is performed in the automatic filter stage, with a cleanable surface-filter cartridge used to provide redundancy, reliance on disposable filters is eliminated.
Read the article online at: https://www.hydrocarbonengineering.com/product-news/02052018/alfa-laval-filter-approved-by-man-diesel-turbo/