Provisional approval for CM2 piston ring coating

The new CM2 coating process combines a reformulated material matrix with modern application technology to deliver greater hardness, improved temperature performance and enhanced durability. The approval follows more than a year of ocean trials onboard containerships using MAN B&W main engines.

The engine designer’s provisional approval envisages further shipboard tests, which if successful will pave the way for adoption of CM2 piston ring technology for a range two-stroke marine engine applications.

Precision Products managing director Scott Rhodes said: “The provisional approval reflects the exceptional results we’ve seen when comparing a lengthy period of CM2 piston ring performance with CM1 in the same two-stroke engine. CM1 coatings are applied using plasma-spraying technology, whereas the latest high velocity oxy-fuel application allows the coating powder to be applied using a mixture of gaseous fuel and oxygen at more than one thousand metres per second. This provides a more compact, harder coating with improved overall adhesion and durability.”

Rhodes added that the approval is expected to open a significant new after-sales market in piston ring maintenance and replacement. The technology is also important for its strategy of developing relationships with licensees, particularly in Asia, he said.

The company promised further R&D announcements in the coming weeks.