Selection of centrifugal pump parts

The selection of centrifugal pump parts depends on factors like the application, fluid properties, operating conditions, and required performance. Below is a guide to choosing key components of a centrifugal pump:

1. Impeller

• Type:

• Closed Impeller – High efficiency, used for clean liquids (water, chemicals).

• Semi-Open Impeller – Handles small solids (wastewater, slurries).

• Open Impeller – For viscous or abrasive fluids (slurries, sewage).

• Material:

• Stainless Steel (SS304/SS316) – Corrosion-resistant for chemicals.

• Cast Iron – Cost-effective for water and non-corrosive fluids.

• Bronze – Seawater & mildly corrosive liquids.

• Hardened Alloys (Chrome, Ni-Hard) – Abrasive slurries.

2. Casing

• Type:

• Volute Casing – Most common, provides steady flow.

• Diffuser Casing – High-pressure multi-stage pumps.

• Material:

• Cast Iron – General-purpose water pumps.

• Stainless Steel – Corrosive fluids.

• PP/FRP (Plastic/Fiberglass) – Highly corrosive chemicals.

3. Shaft & Bearings

• Shaft Material:

• Stainless Steel (AISI 420/316) – Corrosion resistance.

• Carbon Steel – High strength for heavy-duty pumps.

• Bearings:

• Ball Bearings – Standard for small/medium pumps.

• Roller Bearings – Heavy-load applications.

• Ceramic Bearings – High-speed or corrosive environments.

4. Sealing System

• Mechanical Seal (Preferred for high-pressure/leak prevention):

• Single Mechanical Seal – Clean liquids, moderate pressure.

• Double Mechanical Seal – Hazardous/expensive fluids (fuels, acids).

• Cartridge Seal – Easy replacement, minimal alignment issues.

• Packing Gland (Cheaper but higher leakage):

• Used in low-pressure, non-critical applications (water pumps).

5. Wear Rings

• Function: Reduce internal recirculation & improve efficiency.

• Materials:

• Bronze – General use.

• Carbon – High-speed pumps.

• Ceramic – Abrasive services.

6. Coupling

• Rigid Coupling – Precise alignment required (small pumps).

• Flexible Coupling – Absorbs misalignment & vibration.

• Magnetic Coupling – Leak-proof for hazardous chemicals.

7. Base Plate & Mounting

• Heavy-Duty Base Plate – For large pumps to reduce vibration.

• Anti-Vibration Pads – For noise-sensitive installations.

Key Selection Criteria:

✔ Fluid Type (Clean, abrasive, corrosive, viscous).
✔ Flow Rate & Pressure (Head) – Determines impeller size & stages.
✔ NPSH Availability – Avoids cavitation.
✔ Temperature & Pressure Ratings – Affects material choice.
✔ Efficiency & Maintenance Needs – Seals, bearings, and wear parts.

The above content is compiled and published by Zhilong Drum Pump supplier, please specify, to buy oil drum pump, electric drum pump, high viscosity electric drum pump, fuel drum pump, food grade drum pump and so on, please contact us.