Georgia Power, McDonough

Pumping Machinery Consulting and Training

Con Edison Power Plant - 56" Suction Bell Major Repair of

Flowserve 42APM Vertical Turbine Pump, Cooling Water Application

Problem: Severe cavitation of the suction bell made of Ni-Resist Cast Iron. Bell and impeller casing were a single-piece design, thus requiring replacement of the entire expensive part

Solution by a thorough joint effort between Con Edison and Pumping Machinery, LLC: separate design into a 2-piece flanged construction. Replaced upper part was made entirely from stainless steel. The bottom part received stainless steel flange. Two parts were then bolted together, creating a much more reliable, long-lasting part, with superior cavitation resistance

Turn-around time: (4) weeks

APM style design - reliability improvement is the key: cavitation damage solutions	Suction bell and impeller casing was a single integral piece - a major original design oversight	When impeller casing got damaged by cavitation - the entire piece is a problem	Cavitation damage was intense
Upper portion was cut off	Bell portion prepped to receive new stainless steel flange. Upper portion (casing) will become entirely stainless steel, to bolt to the modified bell	Measurements are critical, since the final part must be directly retrofitted in place of the old	Watch the Video of Bell Pre-Machining