Acid Pump Casing Erosion Rebuild

The challenge

An acid transfer pump moves a corrosive, erosive fluid that attacks the casing from two directions at once. The acid chemically eats the metal while the flow scours it, so the casing thins fastest along the volute and the flow path. As that metal is lost, the internal running clearances open up and the wetted surface roughens, and the pump moves less fluid for the same input. Left unchecked, the wall keeps thinning toward a breach of an acid-wetted component, and the unit gets pulled from service. The usual answer is a replacement casting, which is costly and often on a long lead time.

Our approach

We take the pump into the shop and assess where the acid and the flow have taken the metal. We blast the casing and the flow path back to clean, profiled substrate so the repair bonds to bare steel. We rebuild the thinned and eroded sections cold with Belzona 1000 Series composites, working without heat so the casing sees no distortion. Then we reform the internal profile back to the original running clearances and line the flow path with a chemical- and erosion-resistant system keyed to the acid. The result is a smooth wetted surface and tight clearances, ready to go back into service.

1. Assess and mapWe inspect the casing and volute, map where the acid and the flow have thinned the metal, and confirm the fluid so the lining is keyed correctly.
2. Surface preparationWe grit-blast the casing and flow path back to a clean, profiled substrate so both the composite and the lining bond to bare steel.
3. Cold metal rebuildWe rebuild the lost and eroded metal with Belzona 1000 Series composites, working cold so the casing sees no heat distortion.
4. Reform and lineWe reform the internal profile back to the original running clearances and line the flow path with a chemical- and erosion-resistant system matched to the acid.
5. Return to serviceWe finish the wetted surfaces smooth, confirm cure, and return the rebuilt pump to service.