The International Association of Engineering Insurers found that the highest frequency of steam turbine failures worldwide is due to loss of oil. To minimize the effects of loss of oil events, all turbines have a backup or emergency oil system; however, checks of these backup systems are too often neglected. Should the backup systems be inoperable during a loss of power incident, the turbine can coast down with insufficient lubrication, causing expensive component failures. These failures can range from a loss of bearing integrity (wiped bearings) to major seal and rotating component damage, and they result in large costs to the turbine owner, not only in the repair of damage done, but in the cost of lost generation time.
Weekly maintenance checks on emergency lube oil systems should include verifying the adequacy of any battery backup system and testing the pressure switches and controllers that activate backup pumps. These tests should be performed to ensure the backup systems are fully functional should a loss of power or lube oil event occur. These simple efforts of prevention are inexpensive compared to the expenditures related to a turbine coming down without sufficient lube oil.