Sometimes the difficult working conditions of the plant results in a lateral movement of the belt. In this case, a self-centralizing troughing set is used which acts in a way that corrects the belt tracking and maintains it constantly in the central position. The self-centralizing troughing set is designed as a series of rollers arranged in a trough positioned onto the supporting transom which itself is fixed to a slewing ring that permits rotation. The slewing ring (a large ball bearing) permits a rotation limited to 5-8 degrees and is sized in proportion to the vertical loading; a tapered roller bearing assembled to the shaft of the slewing ring, absorbs any forces or overturning pressures.
The installation of the self-centralizing troughing sets is advised to be positioned on the upper strand rather than the return section and used only when the working conditions require. The self-centralizing troughing sets are designed and manufactured in a way that allows them to entirely interchangeable with the normal transom. Normally it is a good standard to install them at an approximate distance of 15 meters from the pulley and at a pitch of about 30m. Self-centralizing troughing sets are designed in 3 different versions: model S, with rigid arm; model F, with pivoting arm with brake; model R, with centralized pivoting arm with brake, for reversible belts.