shaft alignment after seals replacement

[rQuestionEngineering]

Is it a standard procedure to verify shaft alignment after dry gas seals replacement ? (centrifugal compressor coupled to gearbox)

 

[JJPellin]

Yes.

Johnny Pellin

 

[rQuestionEngineering]

The dry gas seals are machined to fine tolerances and nothing changed in other components. If alignment found is out of tolerance, it is time consuming to adjust the gearbox and the drive (considering the piping is connected and the compressor/gearbox dowelled in position). More reasoning is needed to decide on this.

 

[JJPellin]

Good. When you provide additional details, I have the opportunity to provide more meaningful answers. I would still check the alignment. You are basically saying that you would not want to check the alignment because that might drive you to make alignment moves. You are saying it is better to have a problem and not know about it than have a problem and know about it. Even it I did not intend to make alignment moves, I would still measure the alignment so that I could make an informed decision about making moves. Sweeping alignment readings only takes a few minutes. If I was already working on the compressor and already had energy control and a work permit, I would measure the alignment. If the alignment moved from before the reseal, that could indicate that something moved. For example, perhaps the bearing housing dowel pins did not correctly re-position the bearing housing. I would want to know that.

Johnny Pellin