Case Study: Solving a Mechanical Seal Alignment Issue During a Warman Pump Overhaul

A recent Warman rubber lined pump overhaul in the Southern Pumping Specialists (SPS) workshop highlighted how corrosion and component condition can create unexpected challenges during pump reassembly.

The 3/2-CAH pump required a mechanical seal replacement as part of its overhaul. During inspection and assembly, the SPS workshop team identified corrosion on the frame plate journal supporting the retro-fitted mechanical seal housing. This corrosion was enough to affect the alignment of the cartridge seal and required a practical engineering solution to ensure the pump could be returned to service reliably and within the client's budget.

The Pump

The equipment was a 3/2-CAH Warman rubber lined pump undergoing a routine overhaul in the SPS workshop.

While pumps of this type can appear relatively simple to dismantle and rebuild, correct assembly requires precision. The condition and alignment of individual components can have a direct impact on the performance and reliability of the finished pump.

During the overhaul, particular attention was required around the mechanical seal assembly.

The Problem

Inspection revealed heavy corrosion on the frame plate journal where the retro-fitted mechanical seal housing was located.

When the cartridge mechanical seal was installed, the condition of the journal caused the seal to sit slightly out of alignment. This resulted in the seal setting clips breaking and partially collapsing the springs.

Although the issue originated from corrosion on a single component, it had the potential to compromise the mechanical seal and the reliability of the completed pump.

At this point, simply installing a replacement seal was not enough. The underlying alignment issue needed to be addressed.

Assessing the Options

With a new frame plate unavailable, the SPS team assessed two potential repair options.

Option 1: Machine the Frame Plate Journal

The first option was to disassemble the relevant components and machine the corroded journal.

While this could potentially restore the required dimensions, it was considered both costly and higher risk in terms of achieving the precise alignment required for correct mechanical seal operation.

Option 2: Shim the Frame Plate

The second option was to shim the frame plate to compensate for the corrosion and restore the required alignment.

This approach provided a practical alternative without the additional machining costs associated with the first option.

The Solution

SPS used a dial indicator mounted on the pump shaft to accurately measure the position of the frame plate.

The frame plate was then carefully shimmed to establish the correct alignment for the mechanical seal housing.

Rather than relying on visual positioning, the dial indicator provided a controlled and measurable method of correcting the alignment.

The adjustment was completed successfully, allowing the cartridge mechanical seal to be correctly installed and the pump to proceed through the overhaul process.

The Result

The repair enabled the client to receive a tested pump overhaul within their budget, without the need for a new frame plate or the additional cost and risk associated with machining the existing journal.

Most importantly, the solution addressed the underlying alignment issue and allowed the pump to be returned to service with the aim of extending the life of the existing equipment.

Why Experience Matters in Pump Overhauls

This project demonstrates why experienced pump overhaul and repair specialists are important when dealing with industrial and mining equipment.

Issues such as corrosion, wear, dimensional changes and previous modifications may not always be obvious during a visual inspection. However, even relatively small variations can affect components such as mechanical seals, bearings and shafts during reassembly.

In this case, careful inspection identified the problem before the pump was returned to service. By assessing the available options and using accurate measurement techniques, the SPS team was able to develop a solution that balanced reliability, engineering requirements and cost.

Need a Pump Overhaul or Repair?

Southern Pumping Specialists provides industrial pump overhaul, repair and servicing for mining, commercial and other demanding applications.

Our workshop team can inspect, dismantle, assess, repair and rebuild pump equipment, with the focus on finding practical solutions that extend equipment life wherever possible.

Have a pump that requires assessment or overhaul? Contact Southern Pumping Specialists on 1800 810 670 or sales@southernpumping.com.au.