Dewatering Pump Repair for Titanium Company

Malcolm Thompson Pumps’ Perth branch recently undertook a Grundfos dewatering pump repair for a large international titanium chemical company.

The Project

Disappointed with the cost and quality of workmanship from previous pump suppliers, the customer contacted MTP Perth to repair their Grundfos S2 dewatering pump which they use to supply process water to a hydraulic concentrator.

The Grundfos pump had failed due to severe wear to the impeller and volute. The upper mechanical seal appeared to have failed due to running dry as there did not appear to have been oil in the seal chamber since the pump was last overhauled.

A repair done by the customer’s previous supplier resulted in premature failure of a repaired pump. Therefore, they sought the expertise of the MTP Perth team to provide a suitable solution to address the pump failure cost-effectively and to lengthen the life of the pump.

Our MTP Perth staff worked closely with the customer to diagnose the issue. They stripped, tested and assessed the pump in-house and provided a report to the customer outlining the following issues they had discovered along with recommendations:

Grease had dropped into the stator from the upper bearing.
The rotor shaft had corrosion pitting at the mechanical seal area.
The cables had been severely crushed at the glands.
1 of the power cables had also been kinked in the middle.
The impeller was severely worn and was beyond repair.
The volute was severely worn internally with holes broken into some of the external tapped holes.
The upper mechanic seal had a broken stationary face (held together by an o-ring and may have been running dry as there was no evidence of oil in the seal chamber).
The seal chamber had corroded inside indicating the presence of water. There was no evidence of any oil in the seal chamber suggesting that it may not have been filled as required after the last overhaul. The volute side of the seal chamber was worn from sand erosion.
The water sensor in the seal chamber had its wires torn off and when tested had failed to operate.
The water sensor in the top of the motor had the side of the switch broken

All other major components not mentioned above were deemed to be fit for service and were re-used in the repair of the pump.

The Solution

MTP recommended and carried out the following in order to repair the pump:

Cleaned and baked windings on the stator to remove any condensation that was present
Metal spray repaired the shaft and machine of the rotor back to original sizes
Sourced and installed a replacement impeller, volute, cables and water sensor
Overhauled both mechanical seals including replacing the broken face
Cleaned out the corrosion on the seal chamber and filled it with oil as required

To help prolong the service life of the pump, MTP recommended to ceramic coat the impeller and all casing components which would also extend to time between overhauls. The shaft repair was outsourced to a specialise repairer however the remainder of the repair was completed in-house by MTP Perth.

The Results

In total, 4 MTP Perth technicians worked on the repair of the Grundfos dewatering pump over the course of one month. The project was completed and delivered to the customer on time, and within budget.

Upon successful completion of the project, Ashley Earl, the Perth Service Sales Technician who was looking after the job at the time commented “The customer was very satisfied with the repair. The greatest benefit to the customer was the improved longevity of the pump. The pump was previously averaging 6 weeks service life but post-repair they now run 6-8 months between failures. We are now obtaining more work from this customer due to pricing and repair quality as well as being willing to go above and beyond with service where ever possible”.

Before

After

Malcolm Thompson Pumps is a leading pump company with over 40 years industry experience. Operating branches nationwide Malcolm Thompson Pumps distributes an extensive range of world leading pump brands, offers a complete service and repair facility, as well as engineering and design services to create tailored pump package system solutions.

Talk to MTP today to discuss your pump system requirements. Call us on 1800 355 606.