The US Vessel General Permit (VGP), demands the use of Environmentally Acceptable Lubricants (EALs) or the use of an air seal if mineral oils are the acting as lubricants. The latter option, not only requires heavy investment, but there is no guarantee as if the air seal was to fail, ship owners would still be liable to penalties. This briefly explains some of the reasons behind why EALs were the preferred option for ship owners when the VGP new rules came into play.
The problem with white metal bearings and EALs.
DNV GL reported a number of stern tube bearing and seals failures linked to systems running with white metal bearings and EAL lubrication. When white metal is used as a bearing material, it does not hold its properties very well in the acidic environment of some EALs. Moreover, white metal bearings are prone to corrosion and premature failure when exposed to seawater that enters the system.
Tenmat composite bearing materials compatible with EALs.
Tenmat Feroform and Railko are materials specifically designed for this type of application. They provide exceptional performance both in different types of EALs and seawater.
FEROFORM and RAILKO are composite materials capable of withstanding the harshest of environments and specified in marine and offshore applications.
TENMAT materials have strength, durability, dimensional stability, and excellent wear characteristics ensuring continuous performance and protection.
To enquire about a bearing material suitable to run with EALs for stern tube bearings contact us.
