Air pre-heaters are very often used in thermal power stations for heating the air coming from the waste heat. Thanks to the air pre-heaters these electrical stations have a better effi ciency and can achieve higher performances. The working conditions of airpreheaters are very demanding and therefore the installed bearings may be exposed to various types of wearing such as corrosion or abrasion. In addition, the pre-heaters work with a high temperature fl uctuation which also increases the bearing´s technical requirements. ZKL produces large-size thrust spherical roller bearings for the rotors of air pre-heaters which can bear both high thrust as well as radial loads