A severely corroded BB1 horizontally split pump recently arrived at the PSS workshop with extensive deterioration affecting several critical areas of the pump casing and rotating assembly.

The level of corrosion was significant enough that conventional cleaning and minor machining would not have been sufficient. Restoring the pump required a combination of dimensional inspection, precision machining, engineered metal inserts, component restoration, rotor refurbishment and final assembly.

Rather than replacing the complete pump, PSS restored the critical fits and running surfaces so that the equipment could be returned to reliable service.

Restoring the Critical Casing Fits

One of the most challenging areas was the deterioration of the casing ring fits at both the Drive End (DE) and Non-Drive End (NDE).

The damaged areas were machined to remove the corroded material and establish a controlled geometry. New metallic inserts were then manufactured, fitted into the casing and precision-machined to restore the required dimensions and concentricity for installation of the casing rings.

Upper-left photographs:
Before and after restoration of the DE/NDE casing ring fits using engineered inserts and precision machining.

The same repair philosophy was applied to the stuffing box areas, where corrosion had affected the original fits.

The damaged sections were machined and new stuffing-box inserts installed before final machining to restore the required geometry and dimensional accuracy.

Upper-right photographs:
DE/NDE stuffing-box ring restoration — engineered inserts installed and machined to final dimensions.

Rotor Assembly Restoration

Corrosion and deterioration were not limited to the casing. The pump rotor and associated components also required extensive refurbishment.

Components were inspected, repaired or replaced as necessary before the complete rotor assembly was rebuilt and checked prior to installation.

Lower-left photographs:
Pump rotor assembly before refurbishment and after complete restoration.

Returning the Pump to Serviceable Condition

Following casing restoration, rotor refurbishment and dimensional verification, the pump was completely reassembled.

The transformation demonstrates how extensively deteriorated rotating equipment can often be recovered through a carefully engineered repair rather than automatically resorting to replacement.

Lower-right photographs:
Complete BB1 pump before overhaul and after restoration at the PSS workshop.

Extending the Life of Critical Rotating Equipment

Repairs of this nature involve much more than replacing worn parts. Successful restoration requires understanding the original equipment geometry, establishing appropriate repair dimensions, controlling machining tolerances and ensuring that the repaired casing, rotor and stationary components once again operate as an integrated system.

For aging or obsolete pumps, this approach can provide plant operators with an alternative to complete equipment replacement while also addressing problems such as:

• Severe casing corrosion and erosion
• Damaged casing-ring and wear-ring fits
• Deteriorated stuffing-box or seal-chamber fits
• Corroded shafts and rotor components
• Obsolete or unavailable OEM components
• Dimensional deterioration accumulated over many years of service

At PSS Group, our rotating equipment workshop combines inspection, reverse engineering, machining, component restoration and pump assembly capabilities to recover equipment that might otherwise be considered beyond economical repair.

Repair. Re-engineer. Restore. Extend equipment life.