Turbocompressor preservation 1

[Avagadro]

I have a centrifugal compressor/gas turbine package on an FPSO vessel that will not be used for 2 years. Should the rotors be locked in the casings to prevent bearing damage caused by vessel motions?

Vendors always recommend locking rotors during the few weeks voyage to site to prevent damage caused by vessel motions and then we unlock them for the next 20 years even though the vessel is still pitching and rolling and the standby machinery is idle for half that period. It doesn't really make any sense and the vendors' are unable to help.

If the rotors are locked to prevent bearing damage by axial movement then the equipment cannot be periodically rotated by hand which is also recommended to prevent bearing damage.

Does anybody have any experience of damage to sleeve bearings and tilting pad bearings caused by vessel motions or by not rotating for 2 years? Is it all a myth?

Any other points to look out for during preservation?

 

[jsummerfield]

You need some specific support from the supplier for maintenance and preservation. It is desirable that the machinery be inert with a nitrogen seal and enclosed to keep moisture out. This practice prevents rotating the shaft. You can spend lots of money refurbishing the equipment after two-years especially if stored near coastal fabrication yards with salt laden air, etc. Find out what the manufacturer requires to provide a three-year extended warranty. Follow the requirements even if you choose not to pay for the warranty extension.

John