Ensuring Performance and Reliability: Overhauling and Testing Goulds Centrifugal Pumps

At Southern Pumping, ensuring the reliability and longevity of pumping equipment is at the core of what we do. Recently, two Goulds centrifugal pumps (Model: 1X1.50-8) underwent a comprehensive overhaul and rigorous testing process. This article outlines the inspection findings, repair recommendations, and the results of the hydrostatic and dynamic performance tests that validated the pumps' operational excellence.

The Challenge: Heavy Wear and Build-Up

Upon arrival at Southern Pumping, the two pumps were in need of an overhaul. A visual inspection revealed significant grease, dust, and grit build-up across the pump assemblies. Despite the contamination, initial checks showed the shafts, casings, and impellers to be in good condition—a promising start.

Initial Inspection: Key Findings

Our inspection process involved disassembly, cleaning, and evaluation of all major components. The findings were as follows:

• Mechanical Seal: Cartridge-style seals, with rotary and stationary faces made from silicon carbide (Sic), and O-rings made of Viton.
• Impeller: Open-style design, with a diameter of 171.5 mm, made from stainless steel.
• Bearings: 
  • Inboard: 5306C3
  • Outboard: 6207C3
• Seals: Labyrinth-type seals were identified as a candidate for replacement.
• Lubrication: The bearings operated via an oil bath system, with no signs of wear outside the standard range.

The Overhaul Process

Based on the inspection findings, our team implemented the following recommendations:

1. Bearings: Replaced both inboard and outboard bearings to ensure smooth operation and minimize vibration.
2. Cartridge Seals: Sent for refurbishment to restore sealing integrity.
   
3. Gaskets: All gaskets were replaced to prevent potential leaks.
4. Seals: Upgraded the labyrinth seals to more robust lip seals for improved longevity.
5. Coupling Elements: Worn coupling elements were replaced to ensure reliable drive connection.
   

With these refurbishments complete, both pumps were reassembled and prepared for testing to validate their performance under operational conditions.

Hydrostatic Testing: Proving Structural Integrity

Each pump was subjected to a hydrostatic test at a pressure of 840 kPa using a Rothenberger Test Bucket. This test ensures that the pump casing and seals can withstand operational pressures without leaks.

Both pumps passed this critical test, confirming their structural integrity and readiness for service.

Dynamic Testing: Measuring Real-World Performance

To verify operational performance, each pump was subjected to a 2-hour dynamic test, during which bearing temperatures were closely monitored. Results showed steady temperature increases that remained well within acceptable operating limits:

Pump 1 (Serial No. 7780791.1)

Pump 2 (Serial No. 7780791.2)

The stable temperature readings indicated excellent bearing performance and efficient operation across both pumps, especially given the tests were conducted on one of the hottest days of the year with a high ambient temperature.

The Outcome: Ready for Deployment

With the overhaul and testing process complete, both pumps demonstrated exceptional structural integrity and operational performance. The replacement of key components, including bearings, seals, and gaskets, has restored these pumps to like-new condition, ensuring reliability for future service.

This case highlights the importance of thorough inspection, proper overhaul practices, and rigorous testing. By following these processes, Southern Pumping continues to deliver pumps that meet the demanding performance and longevity expectations of our clients.