Cold Water Pump Rebuild

The Situation

Qualtex was engaged to remove, overhaul, and reinstate an auxiliary cold water pump at a major North Island power station. The pump had been in continuous service for over 20 years without a formal overhaul — beyond a typical service interval for equipment of this type and criticality.

The Challenge

Twenty years of service had left the pump assembly in heavily corroded condition, making controlled disassembly difficult. The 12-metre installation depth added further complexity: the connected pipework had to be lifted and broken down in 3-metre sections, with no existing removal procedure to reference.

Before any physical work began, the team developed a methodology for the safe and efficient removal, overhaul, and reinstatement of the complete assembly. This was agreed with the client prior to execution.

What Qualtex Did

Following methodology sign-off, the pump was disassembled on-site and all components transported to the Qualtex workshop in Hamilton. The electric motor was tested and assessed. Pump components were grit blasted, treated, and painted. Corroded pipework fittings and fastenings were replaced with stainless steel equivalents. Shaft bearings and worn surfaces were repaired to specification.

Once all components were overhauled and assembled, the unit was returned to site, reinstalled to the original 12-metre depth, and commissioned.

The Outcome

A critical auxiliary pump that had operated well beyond its service life was returned to reliable, specification-compliant service. The structured approach — developing a removal methodology where none existed, combined with full workshop overhaul rather than a reactive component-by-component repair — means the client has a documented process for future maintenance and a pump that is fit for the next extended service interval.