Why is general purpose grease not recommended for use in RBC bearings?

General purpose grease is often not suitable for use in rotating biological contactor (RBC) bearings due to its typical formulation, which lacks the necessary high load capacity expected in applications where bearings are subjected to significant stress. RBC equipment operates in environments where both load and speed can be substantial, necessitating lubricants that can effectively support these conditions.

High load capability is crucial because it ensures that the grease can withstand the forces generated during the operation of the bearings, maintaining adequate lubrication and protection against wear and tear. Greases designed for high-load applications usually contain specialized additives and have specific properties that allow them to perform optimally under such demanding circumstances.

The other options reference characteristics that while relevant to the performance of bearing lubricants, are not the primary reason general purpose greases are inadequate in this scenario. For instance, while general purpose grease may sometimes be too thick or unsuitable for high temperatures, these factors do not specifically address the load-bearing limitations that are critical in RBC applications. Consequently, the focus on the high load capability emphasizes the importance of selecting a grease formulated specifically for high-load conditions in bearings subject to significant stress.