Wartsila has launched a new bio seal ring product for maritime stern tube seal applications for fixed pitched propeller systems.

The company said in a prepared statement that it is the first seal on the market that works with environmentally acceptable lubricants (EAL), sometimes known as bio-degradable oils, for a lifetime of at least five years.

Conventional seal rings are recommended to be changed at two and a half year intervals.

The benefits of the new seal are both environmental and economic, according to Wartsila. The extended operating life expectancy has a significantly positive impact on dry-dock scheduling and related costs.

The unique features of the bio seal ring have been achieved through improvements in the material formula by including new additives. The product has been tested extensively and proven in the Wartsila Seals and Bearings' R&D facility.

The new product enables compliance with the U.S. Environmental Protection Agency's (EPA) Vessel General Permit 2013 legislation which comes into force on Dec. 19, 2013. From this date all commercial vessels over 79 feet operating in U.S. waters will be required to use EALs in all oil to water interfaces unless deemed technically infeasible to do so.