Centrifugal Pumps: A Buying Guide for Facility Managers

Executive buying summary

Centrifugal pumps are essential for moving fluids throughout a facility, from water and chemicals to slurries and viscous materials. Selecting the right pump involves balancing performance requirements with factors like energy efficiency, material compatibility, and ease of maintenance. Total cost of ownership is influenced by energy consumption, repair frequency, and the lifespan of components. A common risk is selecting a pump that is not adequately sized or specified for the application, leading to premature failure and operational inefficiencies.

• Careful assessment of the fluid being pumped, including its viscosity and temperature, is crucial for selecting the appropriate pump type.
• Energy efficiency is a significant consideration, with modern pump designs often incorporating variable speed drives to optimise performance.
• Compliance with relevant safety standards, such as BS EN 809 and PUWER, is paramount to ensure safe operation.
• Regular maintenance and inspection are essential to maximise pump lifespan and minimise downtime.
• Consider the long-term implications of material selection, particularly when dealing with corrosive or abrasive fluids.

Equipment types compared

Key features to look for

• Material of Construction: The pump's materials must be compatible with the fluid being pumped to prevent corrosion and degradation; ask for material certifications and compatibility data.
• Sealing Arrangement: Mechanical seals or packed glands are critical for preventing leaks; understand the suitability of each for the specific application and potential hazards.
• Impeller Design: Different impeller designs (e.g., closed, semi-open, open) affect efficiency and suitability for different fluid types; discuss the best option for the application.
• Motor Power and Speed: Ensure the motor is appropriately sized for the pump's requirements and consider the benefits of variable speed drives for energy efficiency; request motor performance curves.
• Bearing Type and Lubrication: Bearing condition directly impacts pump reliability; enquire about bearing type, lubrication requirements, and anticipated lifespan.
• Casing Design: The casing must withstand the operating pressure and provide easy access for maintenance; review casing construction and accessibility.
• Noise Levels: Excessive noise can be a workplace hazard; request noise emission data and consider noise mitigation measures if necessary.
• Control and Monitoring Systems: Integration with building management systems can provide valuable data on pump performance and identify potential issues; check compatibility with existing systems.

Pros and cons of each equipment type

End-Suction Centrifugal Pump

Pros: Relatively simple design, widely available, suitable for a broad range of applications.

Cons: Can be less efficient than other designs, may require priming.

Submersible Centrifugal Pump

Pros: Eliminates the need for priming, suitable for applications where the pump is located below the fluid level.

Cons: More complex to maintain, potential for overheating if not properly cooled.

Multi-Stage Centrifugal Pump

Pros: High head capabilities, efficient for high-pressure applications.

Cons: More complex design, higher upfront cost.

Self-Priming Centrifugal Pump

Pros: Eliminates the need for manual priming, convenient for applications where air is present in the suction line.

Cons: Can be less efficient than end-suction pumps, may have a shorter lifespan.

Hygienic Centrifugal Pump

Pros: Easy to clean and sanitise, suitable for food and beverage processing and pharmaceutical applications.

Cons: Typically higher upfront cost, may have limited material options.

Which facilities each type suits

• End-Suction Centrifugal Pump: General water supply, irrigation, cooling towers, chemical transfer.
• Submersible Centrifugal Pump: Drainage, sewage treatment, well water extraction, flood control.
• Multi-Stage Centrifugal Pump: Boiler feed water, high-pressure cleaning systems, reverse osmosis.
• Self-Priming Centrifugal Pump: Applications where air is frequently present in the suction line, such as transferring fluids from tanks.
• Hygienic Centrifugal Pump: Food and beverage processing, pharmaceutical manufacturing, dairy production.

Buyer's checklist

1. Confirm the fluid's properties (viscosity, temperature, solids content, corrosiveness) and operating conditions (flow rate, head).
2. Verify compliance with relevant safety standards (BS EN 809, PUWER) and regulatory requirements (ATEX/UKEX if applicable).
3. Assess the need for UKCA or CE marking and ensure the pump meets the necessary requirements.
4. Determine the required level of energy efficiency and explore options for variable speed drives.
5. Establish a maintenance schedule and ensure access to spare parts.
6. Consider the pump's noise emissions and implement noise mitigation measures if necessary.
7. Validate the pump's performance through testing and commissioning.
8. Provide adequate training to personnel responsible for operating and maintaining the pump.
9. Secure a comprehensive service and support agreement from the supplier.
10. Evaluate the pump's lifecycle cost, including energy consumption, maintenance, and replacement costs.