Whether you’re a homeowner dealing with flooding, a contractor installing pump systems, or a professional maintaining industrial equipment, understanding pump terminology is essential. This comprehensive glossary covers everything from basic pump components to advanced technical concepts, helping you make informed decisions about your pumping needs.
Why Understanding Pump Terminology Matters
Proper pump terminology knowledge helps you:
- Communicate effectively with pump specialists
- Make informed purchasing decisions
- Understand pump specifications and performance charts
- Troubleshoot pump problems effectively
- Ensure proper installation and maintenance
A
Affinity Laws
Mathematical relationships that describe how pump performance changes with impeller diameter, speed, and fluid density. These laws help predict pump behaviour when operating conditions change.
Air Lock
A condition where air becomes trapped in the pump or suction line, preventing proper water flow. Common in self-priming pumps and can cause pump failure if not addressed.
ATEX Rating
European safety certification for equipment used in explosive atmospheres. Critical for pumps operating in hazardous environments with flammable gases or vapours.
Axial Flow Pump
A pump where water flows parallel to the impeller shaft. These pumps are ideal for high-volume, low-head applications like flood control and irrigation.
Axial Thrust
The force exerted along the pump shaft due to pressure differences across the impeller. Must be managed through proper bearing design and thrust balancing.
B
Backflow
The reverse flow of water through a pump system, potentially causing contamination or damage. Prevented using check valves and proper system design.
Best Efficiency Point (BEP)
The operating point where a pump achieves its highest efficiency, minimising energy consumption and wear. Pumps should operate as close to BEP as possible for optimal performance and longevity.
Booster Pump
A pump designed to increase water pressure in existing water systems. Essential for buildings with inadequate water pressure or multi-storey applications.
Bypass Valve
A valve that allows water to recirculate within the pump system, preventing dead-heading and providing flow control during startup.
C
Cavitation
The formation and collapse of vapour bubbles in the pump due to low pressure, causing noise, vibration, and potential damage. A critical issue in pump operation that must be prevented through proper NPSH management.
Centrifugal Pump
The most common pump type, using a rotating impeller to transfer energy to the fluid through centrifugal force. Includes most sump pumps, drainage pumps, and surface-mounted pumps.
Check Valve
A one-way valve that prevents backflow, protecting pumps from reverse rotation and maintaining prime. Essential component in most pumping systems.
Close-Coupled Design
A pump configuration where the pump is directly mounted to the motor shaft without a separate coupling. Common in smaller pumps for space efficiency.
Closed Impeller
An impeller design with front and back shrouds covering the vanes, providing higher efficiency and better performance in clean water applications.
Clogging
The blockage of pump passages by debris or solids. A major concern for sewage pumps and dirty water pumps.
D
Dead Head
Operating a pump with no flow (closed discharge valve), causing overheating and potential damage. All pumps have maximum allowable dead head time specifications.
Dewatering Pump
A pump specifically designed to remove water from excavations, basements, or other areas where water accumulation is problematic.
Diffuser
A component that converts velocity energy from the impeller into pressure energy, typically through gradually expanding passages.
Discharge Head
The vertical distance from the pump centreline to the highest point in the discharge system, plus any additional pressure requirements.
Dirty Water Pump
A pump designed to handle water containing suspended solids, debris, or other contaminants. Features larger passages and more robust construction.
Dry Run Protection
Safety features that prevent pump operation without sufficient water, preventing damage from overheating and seal failure.
E
Efficiency
The ratio of useful hydraulic power output to electrical power input, expressed as a percentage. Higher efficiency means lower operating costs.
End Suction Pump
A centrifugal pump with suction nozzle on the end opposite the drive motor. Common configuration for many applications.
Engine Driven Pump
A pump powered by an internal combustion engine rather than an electric motor, useful for remote locations or emergency applications.
F
Float Switch
An automatic control device that starts and stops pumps based on water level. Essential for sump pump systems and automatic drainage applications.
Flow Rate
The volume of water moved by a pump per unit time, typically measured in litres per minute (LPM) or cubic metres per hour (m³/h).
Foot Valve
A check valve installed at the bottom of the suction line to maintain prime and prevent backflow.
Friction Loss
The pressure loss due to water friction in pipes, fittings, and valves. Must be calculated for proper pump sizing.
G
Gland Packing
Traditional sealing method using braided materials around the pump shaft. Being replaced by mechanical seals in most modern applications.
Grinder Pump
A type of sewage pump with cutting mechanism to break down solids before pumping. Essential for sewage systems with limited pipe sizing.
H
Head
The energy added to the fluid by the pump, measured in metres of water column. Includes elevation, pressure, and velocity components.
High Head Pump
A pump designed to operate against significant pressure or elevation, typically over 30 metres of head.
Horizontal Pump
A pump mounted with horizontal shaft orientation, common for larger installations and industrial applications.
I
Impeller
The rotating component that transfers energy to the fluid. Available in various designs including open, semi-open, and closed configurations.
Impeller Diameter
The outer diameter of the impeller, which affects pump performance. Can be trimmed to adjust pump curves.
Industrial Water Pump
Heavy-duty pumps designed for continuous operation in industrial applications with robust construction and materials.
Inline Pump
A pump where suction and discharge connections are in line, allowing installation directly in the piping system.
J
Jet Pump
A type of pump using the venturi effect to create suction, commonly used in shallow well applications.
K
Kilowatt (kW)
Unit of electrical power consumption, important for calculating operating costs and electrical requirements.
L
Lift
The vertical distance a pump can raise water, limited by atmospheric pressure and pump design.
Low Flow Cutoff
Protection feature that shuts down the pump when flow drops below a minimum threshold, preventing damage.
M
Magnetic Drive Pump
A pump using magnetic coupling instead of mechanical shaft seals, providing leak-free operation for hazardous or sensitive fluids.
Maximum Head
The highest head at which a pump can operate, typically at zero flow conditions.
Mechanical Seal
A sealing device that prevents leakage along the rotating shaft using smooth, hard faces pressed together.
Motor
The driving component of electric pumps, available in single-phase and three-phase configurations.
Multistage Pump
A pump with multiple impellers in series to achieve higher heads than possible with a single impeller.
N
Net Positive Suction Head (NPSH)
A critical parameter preventing cavitation. NPSH Available must exceed NPSH Required for proper pump operation.
Non-Clog Impeller
An impeller design that resists clogging from solids and debris, essential for sewage and wastewater applications.
O
Open Impeller
An impeller without front and back shrouds, better for handling solids but less efficient than closed impellers.
Operating Point
The intersection of pump curve and system curve, determining actual flow and head in a given system.
Overload Protection
Electrical protection that prevents motor damage from excessive current draw due to system problems.
P
Parallel Operation
Operating multiple pumps simultaneously to increase total flow capacity whilst maintaining the same head.
Petrol Engine Water Pump
Portable pumps powered by petrol engines, ideal for emergency use and remote locations without electrical power.
Pond Pump
Specialised pumps for water circulation in ponds and water features, designed for continuous operation and fish-safe materials.
Positive Displacement Pump
A pump that moves a fixed volume of fluid with each cycle, providing constant flow regardless of pressure.
Priming
The process of filling the pump and suction line with water to enable proper operation. Critical for centrifugal pumps above the water source.
Puddle Pump
A low-profile pump designed to remove water from flat surfaces down to very shallow depths, ideal for flooding situations.
Pump Curve
A graph showing the relationship between flow rate and head for a specific pump at a given speed.
Q
Quick Connect
Coupling systems allowing rapid connection and disconnection of hoses and fittings without tools.
R
Radial Flow Pump
A pump where water flows perpendicular to the shaft, typical of most centrifugal pumps.
Relief Valve
A safety valve that opens at a preset pressure to protect the system from overpressure conditions.
Rotary Pump
A positive displacement pump using rotating elements to move fluid, common in oil and viscous fluid applications.
Run-Dry Protection
Systems that prevent pump operation without adequate water flow, protecting against seal and bearing damage.
S
Self-Priming Pump
A pump capable of creating its own prime by evacuating air from the suction line. Essential for applications above the water source.
Series Operation
Operating multiple pumps in sequence to increase total head whilst maintaining the same flow rate.
Sewage Pump
A pump designed to handle wastewater containing solids and debris. Features larger passages and robust construction.
Shaft Seal
Any device used to prevent leakage along the rotating pump shaft, including mechanical seals and packing.
Shut-off Head
The head developed by a pump at zero flow conditions, representing the maximum pressure the pump can generate.
Small Sump Pump
Compact sump pumps designed for residential applications and smaller basements or cellars.
Specific Speed
A dimensionless parameter characterising pump impeller design and performance characteristics.
Strainer
A device that removes debris from the water before it enters the pump, protecting internal components.
Submersible Pump
A pump designed to operate completely underwater, with a sealed motor and electrical connections.
Suction Head
The height of water column above the pump centreline that assists in moving water to the pump inlet.
Suction Lift
The vertical distance the pump must lift water from the source to the pump inlet, limited by atmospheric pressure.
Sump Pump
A pump installed in a sump pit to remove water from basements and cellars, preventing flooding damage.
Swimming Pool Pump
Specialised pumps for pool circulation systems, designed for continuous operation with appropriate flow rates for filtration.
T
Three-Phase Motor
More efficient motor type for larger pumps, providing smooth operation and better power factor.
Throttling
Restricting flow using valves to control pump operation, though less efficient than variable speed control.
Total Dynamic Head (TDH)
The total head against which a pump must operate, including elevation, pressure, and friction losses.
Turbine Pump
A type of pump using multiple staged impellers, common in deep well applications.
U
Unloader Valve
A valve that reduces pressure during pump startup to reduce motor starting load.
V
Variable Frequency Drive (VFD)
Electronic device that controls motor speed by varying the frequency of the electrical supply, providing efficient pump control.
Velocity Head
The kinetic energy component of total head, typically a small portion except in high-velocity systems.
Vertical Pump
A pump mounted with vertical shaft orientation, often used in pit installations and limited space applications.
Volute
The spiral casing around a centrifugal impeller that converts velocity energy to pressure energy.
W
Water Hammer
Pressure surges caused by sudden flow changes, potentially damaging pumps and piping systems.
Well Pump
Pumps specifically designed for water well applications, including shallow well jet pumps and deep well submersible pumps.
Wet End
The portion of the pump that comes in contact with the pumped fluid, including the volute, impeller, and wear plates.
X
X-Ray Inspection
Non-destructive testing method used to inspect pump castings and welds for defects in critical applications.
Y
Yield Point
The stress level at which pump materials begin to deform permanently, important for pressure rating calculations.
Z
Zero Flow
Operating condition where the pump generates head but produces no flow, typically at shut-off conditions.
Zone of Operation
The recommended operating range for a pump, typically between 70-120% of best efficiency point flow.
Conclusion
Understanding pump terminology is crucial for selecting, installing, and maintaining pump systems effectively. Whether you’re dealing with a simple sump pump installation or complex industrial applications, this knowledge helps ensure optimal performance and longevity.
For specific pump recommendations and expert advice, explore our comprehensive range of pumps and accessories, or contact our technical team for personalised assistance with your pumping requirements.
Remember that proper pump selection depends on understanding your specific application requirements, including flow rate, head, fluid characteristics, and operating conditions. When in doubt, consult with pump professionals to ensure optimal system performance and reliability.