I DO AGREE THAT THE VT PUMP VIBRATIONS ARE HIGH. HOWEVER THE SPEED ALSO IS LOW IN THE RANGE OF 750 TO 1450RPM. SO WHAT WOULD BE THE EXTREAM LIMIT OF ACCEPTANCE AT EACH SPEED? WE ARE ALSO FACING A PROBLEM OF HIGH SHAFT RUN OUT . IF WE MAINTAIN THE SHAFT RUN OUTS WITH IN 0.05 TO 0.12 MM THEN I THINK THE PUMP VIBRATIONS WILL COME DOWN. IN VARIABLY THE SHAFT RUN OUTS AFTER ASSEMBLY WITH SETTING DEPTH MORE THAN 5 MTRS WILL NOT BE WITH IN LIMIT. IF WE CONTROL THE SHAFT RUN OUTS THEN PROBABLY THE VIBRATIONS WOULD COME DOWN.

Jayant,

For vertical pumps . shaft run out is not the problem. Its reed natural frequency which can be tested and adjusted as per bump test results so that problem will be solved permantly as per installtion.