Submersible Pumps

How Centrifugal Pumps Work

Centrifugal pumps use a rotating impeller to impart velocity to the liquid, converting kinetic energy into pressure as it exits the volute casing. Fluid enters axially at the eye of the impeller and is discharged radially. This design excels in high-flow, moderate-head applications with clean or lightly contaminated liquids.

Key Components

Explore the main parts of a typical single-stage horizontal end-suction centrifugal pump:

Labeled cross-section of single-stage centrifugal pump with closed impeller — Cross-section view showing impeller, casing, shaft, and seals

Exploded/labeled diagram of single-stage centrifugal pump — Basic exploded view with key parts highlighted

Performance Characteristics & Curves

Centrifugal pump performance is shown on curves plotting Head (H) vs Flow (Q), along with efficiency, power, and NPSHr. The curve shows an inverse relationship: higher flow results in lower head. The Best Efficiency Point (BEP) is the optimal operating zone for maximum efficiency and longevity.

Here are examples of typical performance curves (including efficiency and NPSH):

Full centrifugal pump performance curve showing H-Q, efficiency, power, and NPSHr — Complete performance curve with all key parameters

Centrifugal pump curve with head vs flow, efficiency, and NPSH — Standard H-Q curve with efficiency islands and NPSHr

Typical head vs flow performance curve for centrifugal pump — Basic Head vs Flow curve highlighting BEP

Advantages & Disadvantages

Advantages

High efficiency (typically 60–85% at BEP)
Simple design with few moving parts → low maintenance
Cost-effective for high-flow applications
Smooth, continuous flow with minimal pulsation
Wide range of materials for compatibility

Disadvantages

Requires priming (unless self-priming)
Performance drops sharply at low flow/high head
Susceptible to cavitation if NPSHa < NPSHr
Not ideal for high-viscosity or solids-heavy fluids
Limited suction lift capability

Product Gallery – Real-World Examples

View examples of horizontal end-suction centrifugal pumps in industrial blue finish (common for EN 733-compliant models):

Pentair Fairbanks Nijhuis NC Series horizontal end-suction centrifugal pump — Industrial blue end-suction model

Vertiflo Series 1600 industrial horizontal end-suction vortex pump — Heavy-duty horizontal design

Vertiflo Series 1400 base-mounted end-suction pump — Standard close-coupled industrial pump

How to Select the Right Centrifugal Pump

Match your needs to the pump curve: Calculate required flow (Q) and total dynamic head (TDH). Aim to operate near the BEP (within ±10–20%). For EN 733-compliant pumps, typical ranges include:

Flow: 10–360 m³/h (depending on model size)
Head: 10–95 m
Consider NPSHr, fluid temperature (-10°C to +90°C standard), and motor power (3–75 kW typical)

Consult the spec sheet for exact curves and select based on efficiency, materials, and application.