Is this a center hung rotor? direct drive? or belt drive?
If center hung, is it double suction or single suction?
If center hung, double suction, does it have a solid center "plane" between the 2 suction ends?
Is it an overhung rotor? direct drive? or belt drive?
Is it sleeve bearings? or anti-friction bearings?
If anti-friction bearings, what holds them to the shaft? Tapered sleeve? Or straight bore interference fit?
What exactly did they do during the "inspection" you suggested?
When all trial weights and permanent weights are removed, does the phase and amplitude return to basically the same original readings?
Quote: "In every Balancing attempt Fan responding to correction weights but Vibration increasing after another run ."
What do you mean by "but Vibration increasing after another run ." Another balancing run with new trial weights? or just another start-up after the balance job was supposed to be complete and the fan restarted?
What is the sideband spacing of the data near the 20,000 to 25,000 cpm area on the Fan Drive End bearing? And on the closely spaced (less than 1x) Fan NDE bearing from 5,000 cpm out to 30,000 cpm? It looks about like 1/3 rpm.