Case Study: Simplifying a Complex Pump Installation to Improve Reliability

The Challenge

An existing pump installation had been configured with a complex drive arrangement to compensate for limitations in the available power supply and to improve Net Positive Suction Head (NPSH) performance. To achieve the required operating conditions, the system used a belt drive connected via a shaft extension, effectively reducing the pump speed.

While the configuration allowed the pump to meet its hydraulic requirements, the mechanical arrangement created ongoing operational issues. The belt drive and associated components required frequent maintenance, leading to regular downtime and repeated replacement of drive parts. Over time, this created significant reliability concerns and increased maintenance costs for the operator.

The application itself also presented additional challenges. The pump was handling wastewater containing hydrocarbons, requiring careful attention to materials selection and sealing arrangements to ensure safe, durable operation in a demanding service environment.

The Approach

After reviewing the installation, the team identified an opportunity to simplify the system while still achieving the required hydraulic duty.

Instead of relying on mechanical speed reduction through a belt drive, the solution focused on selecting a more suitable pump model and optimising its hydraulic performance. By trimming the impeller and carefully evaluating the pump’s operating curve, the design was able to achieve improved NPSH performance without needing to reduce pump speed through external drive components.

This change allowed the system to be converted to a direct drive configuration, eliminating the belt drive and its associated maintenance requirements. At the same time, the pump specification was updated with appropriate materials and sealing systems to handle the hydrocarbon-contaminated wastewater safely and reliably.

The Solution

The redesigned installation included:

• A correctly matched pump model suited to the duty conditions
• Impeller trimming to optimise hydraulic performance and NPSH capability
• A direct drive configuration, removing the need for belt-driven speed reduction
• Materials and sealing arrangements selected specifically for hydrocarbon-contaminated wastewater

The Outcome

The final result was a significantly simplified and more robust pumping system.

By eliminating the belt drive and reducing mechanical complexity, the installation achieved:

• Improved reliability and system uptime
• Reduced maintenance requirements
• Lower ongoing operational costs
• A safer and more suitable configuration for hydrocarbon-containing wastewater

The redesigned solution demonstrates how careful pump selection and hydraulic optimisation can remove unnecessary mechanical complexity, delivering a more efficient and dependable long-term outcome for operators.