Mothballing - Pumps Preservation Practices

[luca]

What are the best practices when preserving pumps for mothablling a complete unit? For sure more than 6 months time is expected.

[tiror]

Straight answer is that preservation is done through purging of dry air or nitrogen.

However, it depends as you have three major options:
Option A: Oil Flooding
Fill pump casing + internals with: rust preventive oil / inhibited mineral oil
Rotate shaft to coat all internals
Best for:
Centrifugal pumps
Lubricated internals
Option B: Vapor Phase Corrosion Inhibitors (VCI)
Place VCI emitters inside casing
Seal the pump completely
It is best when oil filling is not practical and there are large systems
Option C: Dry Air / Nitrogen Blanketing
Purge with dry air or nitrogen
Maintain slight positive pressure (~0.1–0.3 barg)
This is THE practice, used in high-end petrochemical plants.

[ivani1]

Just note that before startup, you must take care of the following:
Drain preservation oil
Flush system again
Reinstall seals (or inspect)
Check alignment
Replace lubricants
Insulation resistance (for motor)