The storm pumps at a wastewater treatment plant had been in operation for around 25 years and had reached the point where a complete overhaul was required before a potentially serious failure was experienced. Regular vibration monitoring had highlighted the need for a refurbishment.
Chris Weston, area sales manager at Sulzer, said: “Having detailed what Sulzer could offer in terms of support, we took the opportunity to look at the pumps during the visit. We explained how we would lift and transport both the pump and motors to our service centre as well as the timeframes involved in completing the necessary work.”
Sulzer put together the lift plan documentation as part of the method statement and risk assessment. The pump had to be partially disassembled and removed in three sections. The field service team used a lifting tool to remove the pump from the dry well.
The process was further complicated because the main shaft, which required replacement, would not come apart and had to be cut in one place to enable removal. Sulzer provided a solution to manufacture a new shaft section after the OEM provided a lead time for a replacement of several months.
The project involved the overhaul of the pump and motor assemblies, all of which could be completed at the same location. Sulzer provided field service engineers to arrange the lift and removal of the pump as well as the reinstallation of the full unit including motor, after the refurbishment had been completed.
Once the pump had been disassembled, all the components were inspected and identified for replacement or re-engineering. A considerable amount of corrosion was found on the impeller and the suction sleeves. Sulzer applied a specialist coating on all parts that required additional protection against corrosion to extend the operating life of these components.
During the project, some of the maintenance team from the wastewater treatment plant visited the service centre to check on progress and see for themselves the levels of corrosion inside the pump.
Having discovered the full extent of the wear and tear on the pumps after 25 years, the site maintenance team is putting together a plan with Sulzer to refurbish the remaining pumps. This can be achieved without affecting the capacity of the site, with Sulzer providing the engineering and logistics support for a turnkey project.
Weston concluded: “Our network of service centres means we always have a local presence that can provide a fast and responsive solution for any rotating equipment. Our one-stop-shop enables us to keep all mechanical and electrical repairs in-house, optimising repair times and minimising any downtime for our customers.”