How to do the alignment for vertical pumps with motor

[siddiq191]

We have a vertical turbine pump having capacity of 20000cum per hour and pressure head 16.5m at intake plant.I want to know how alignment of pump shaft is done with motor shaft.Does alignment procedure for vertical pump differ from horizontal pump alignment in anyway? IF so,How?
We are using rigid coupling with adjusting spacer for coupling the pump with motor.

Can anybody explain me in detail?

 

[Artisi]

Think a lot more detail is required before anyone commits themselves, like motor / pump mounting flange arrangement, e.g. does the motor mounting flange have a spigot to register with a mating spigot on the pump mounting flange or is the motor mounting flange flat without any register / likewise flat pump mounting flange.

I would suggest a read of the pump installation instructions wouldn't go amiss nor would a good visual inspection of the pump / motor unit.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[JJPellin]

Most pumps of this configuration would have a register fit (pilot, spigot) on the mounting face as Artisi described. If it does not, I would align the motor to the stuffing box using a dial indicator supported from the motor shaft. First, I would read the axial face of the stuffing box to see if shims were needed to correct angularity. Then I would read against the stuffing box bore to make the necessary horizontal moves to acheive the offset alignment.

I would not recommend using a laser alinment system. The laser system would require you to roll both shafts which would make it neccessary to couple up. With a rigid coupling, this would be like trying to align a solid shaft to itself. The laser would show near perfect alignment even if the alignment was very poor.

Johnny Pellin

 

[JJPellin]

If you were to attempt to align the motor to the pump shaft, rather than the stuffing box, you need to account for the clearane in the pump bushings. Uncoupled, the pump shaft may not be in the center of the bushings. I would install a temporary dummy bushing to hold the shaft on center and then use the dial indicator to sweep the pump shaft. This would be done uncoupled, as I noted above.

Johnny Pellin