The standard outside clean flush is the preferred method of lubricating the sleeve bearings on the NM3171. For abrasive applications where no outside flush is available, the sealed bearing arrangement is an ideal solution. Carbon bearings are lubricated with grease and isolated from the media by dual lip seals. A spring loaded grease cup maintains a constant pressure on the grease. Due to the fact that the pump’s vinylester material of construction has good insulating properties, it is necessary to flush the outside of the steady bearing to disipate heat. To accomplish this, a flush line is run from the pump discharge to each steady bearing.