ABSTRACT
The chilled-water system is a closed-circuit system. In multi-story buildings, the pumps are generally located in the basement area, and as a result, a rather high static head prevails at the suction of the pumps. Although some extremely small centrifugal pumps may be fitted with internal grease-lubricated sleeve bearings, the rotor of a normal centrifugal pump is supported by two external bearings of either the sleeve on antifriction type. The mechanics of corrosion-erosion attacks in boiler feed pumps first became the subject of considerable attention in the early 1940s, when it became desirable to use feedwater of a scale-free character. If the original pump capacity is liberally selected, there may be no indication that anything is wrong until such time that deterioration of metal has progressed to the point that the original margin has been "eaten up."
