With COVID19 still sweeping the globe, access to pump parts as well as the import thereof has become a massive challenge. With the intermittent closure of ports, customs services, warehouses and OEM offices, mines are seeing an increase in downtime as well as an ever increasing backlog on new pumps and the refurbishment and repair of existing pumps.
Mechanical Rotating Solutions were recently called upon to repair two Southern Cross close coupled 135×100-315 evaporator booster pumps driven by 160kw 525v 2 pole electric motors for a coal mine in Mpumalanga.
“The Southern Cross range of ISO end suction pumps are single-stage, centrifugal volute pumps with axial suction port, radial discharge port and horizontal shaft. Whilst the Southern Cross ISO pumps are suitable for a variety of applications from pumping potable water and irrigation to pumping aggressive chemicals, the availability of spare parts for specific models has become very challenging.” Says Franscois Steenkamp CEO of Mechanical Rotating Solutions.
Having been able to rewound the motors in-house and fit new bearings, it also became evident that the volutes of the pumps was in dire need of refurbishment as it was badly worn.
“After grit blasting, the application areas around the volute were masked for the application of Belzona 1111 Super Metal, an epoxy paste grade composite for metal repair. This was used to reconstruct the areas damaged by corrosion, rebuilding the original surface profile. This solvent-free composite provides excellent corrosion resistance and ensures the substrate is protected when it comes into contact with an abrasive material. Used in conjunction with a product like Belzona 1341 Supermetalglide, with its unique combination of properties such as self-levelling application as well as hydrophobicity and hydraulic smoothness, it combines to offer the perfect solution for lining the hydraulic passages of pumps”. Says Steenkamp.
After MRS performed all the in-house machining, new wear rings were manufactured and installed on both the suction and stuffing box sides of the volute whilst making sure that clearances and specifications were still met.