Moving the pitot tube discharge and rearranging the pump to a between bearing (BB) also removes all mechanisms for heating the suction fluid. This arrangement uses an integral gear drive. An external gearbox increasing speed is commonly used with a conventional overhung pitot tube pump, given that they are typically operated at speeds above a two pole motor on most applications. Now that the pitot tube discharge does not penetrate the rotor cover, labyrinth leakage is eliminated. Eliminating these factors eliminates the need for adjustment on fluids with steep vapor pressure curves. Tests confirm these changes have resulted in a 50% reduction in NPSHr on water over conventional overhung pitot tube pumps.
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