Rotary kilns are always subjected to a natural down thrust due to their inclination. The down thrust is absorbed by the thrust device – hydraulic or mechanical. The function of the thrust device is to transfer the axial load from the rotary kiln to one or several supports and to maintain the rotary kiln in the axial position. Retrofitting of an existing older model of thrust device or a non-Valmet model to either a mechanic or hydraulic thrust device can be done during a short stop. This makes it possible to install the updated technology during scheduled shutdown and optimize kiln availability without loss of production.