Jump to terms about, Pump Components, Performance Metrics or System Design & Operation
Pump Components
Impeller
The rotating component that imparts velocity and pressure to the fluid.
Open Impeller
Vanes are attached to a central hub with no shroud; ideal for slurries and solids.
Closed Impeller
Vanes are enclosed between two shrouds; used for clean liquids.
Vane
Blade-like structure on the impeller that directs fluid movement.
Mechanical Seal
A device that prevents leakage along the pump shaft.
Seal-less Pump
Pump designs that do not use traditional seals (e.g., magnetic drive, canned motor).
Magnetic Drive Pump
A pump that uses a magnetic coupling to drive the impeller without a physical shaft seal.
Diaphragm Pump
A positive displacement pump that moves fluid using a flexing diaphragm.
Peristaltic Pump
Pump that moves fluid by compressing a flexible hose with rotating rollers.
Submersible Pump
Designed to operate while submerged in the pumped fluid.
Performance Metrics
Flow Rate
The volume of fluid a pump moves over time, typically expressed in L/min, m³/h, or GPM.
Head
The energy or pressure generated by a pump, measured in meters or feet.
Total Dynamic Head (TDH)
The total head a pump must overcome, including static head, friction loss, and discharge pressure.
Static Head
The vertical height difference between the source and discharge point.
Dynamic Head
The portion of head related to fluid velocity and elevation.
Best Efficiency Point (BEP)
The point on a pump curve where it operates most efficiently.
Pump Curve
Graph that shows pump performance across various flow and head values.
System Curve
A plot of the system’s resistance (head vs flow), used to match with the pump curve.
Net Positive Suction Head (NPSH)
- NPSH Available (NPSHa): The actual pressure at the pump suction.
- NPSH Required (NPSHr): The minimum pressure the pump needs to avoid cavitation.
Affinity Laws
Equations that show how flow, head, and power change with speed or impeller size.
Viscosity
A measure of a fluid’s resistance to flow, which affects pump efficiency.
System Design & Operation
Suction Lift
The vertical distance the pump must lift fluid from the source to the pump inlet.
Flooded Suction
Configuration where fluid flows to the pump by gravity (source above pump).
Priming
Filling the pump and suction line with liquid to expel air before starting.
Self-Priming Pump
A pump designed to evacuate air and begin pumping without manual priming.
Backflow
Unintended reverse flow of fluid, typically prevented with check valves.
Slurry
A mixture of liquid and solid particles, often abrasive and difficult to pump.
Cavitation
Formation and collapse of vapor bubbles in the liquid, causing damage to pump internals.
Download a PDF of all these terms: Glossary of Pumping Terms.pdf