Abstract: A multistage centrifugal pump having a last stage diffuser which acts as a compensator to load the suction and intermediate pressure gaskets during pump operation and pump stand-by. The last stage diffuser is designed as a spring which deflects under varying conditions and imparts a spring force on the channel rings during assembly, stand-by and other operating conditions.

Abstract: A segmental ring centrifugal pump wherein the channel ring and the diffuser/crossover hydraulics are formed as a single monolithic casting. By casting the diffuser and the channel ring as a unit, the monolithic diffuser channel ring member and the diffuser vanes provide structural support to the channel ring. The channel ring wall thickness has been reduced by taking advantage of the reinforcing function of the monolithic cast piece. The reinforcement of the channel ring wall and the minimum wall thickness can be adjusted by modifying the radius between the diffuser vanes and the channel ring.