Serious pump problems

[Craphandler]

Hello all. I am new here and was wondering if you could help me out. We have a "brand new " installation of 3 VFD operated, 600hp End Suction Horizontal 12 x 14 Centrifugal pumps rated at 5780 gpm @ 233 ft. Since day one they have vibrated excessively(.80 to 2.5 in/sec RMS). I thought the manufacturer was Holy Sh**! or Shut it down! since that was usually called out when it ran. The manufacturer is saying that it is vortexing that is causing the vibratione even though there was 18+ ft of head and minimal flow at the time. We had a detailed (expensive) vibration analysis done by a well respected company. They indicated that the shaft was wobbling due to inadequate effective stiffness in the bearings and a poor structural strength of the base. We can't use the pumps (going on 2 years now)and the manufacturer is obstinate about the cause. My question is am I missing something or have the laws of physics been suspended regarding the vortex issue.
Has ayone run into a situation like this and if so what was the resolution.

Thanks in advance for you time.

 

[gbam]

Sounds like its time Lawyer up.

 

[Craphandler]

Thanks gbam. I was afraid that is what the answer would be. Looks like it is one more thing to add to the already extensive list of items in the litigation.

 

[dik]

Have they been installed in compliance with the manufacturer's recommendations?

Dik

 

[bimr]

It is not clear but I assume that you are talking about submersible pumps. You should not have vortexing with 18 feet of water over the pumps.

You have not said anything about the pump arrangement. The pump arrangement is critical. It is possible that you may have flow currents in the wet well that are causing a problem.

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[JedClampett]

CH, are you the owners representative or the designer?
And by the way, love your handle.

 

[chicopee]

".... installation of 3 VFD operated, 600hp End Suction Horizontal....". I am confused by that statement.
Schematic would be a help. Also answering above question about type of pump would help.