Seal Arrangement: Each ZF thruster is standard equipped with an extremely reliable seal arrangement. In case the rules and regulations require special environmental protection, the thruster can be executed with a special seal arrangement for biodegradable oil (EAL) with active pressure on the seals in order to compensate water pressure.
The seal arrangement, in combination with mineral oil as main lubrication, achieves cost savings of approximately 75% in comparision to a thruster completely filled with biodegrable oil.