Glossary
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Abrasion Resistance
The ability of pump materials to withstand wear caused by solid particles suspended in the fluid being pumped. Pumps handling slurries or gritty fluids must be made from highly abrasion-resistant materials to extend service life.Air-Operated Double Diaphragm Pump (AODD)
A type of positive displacement pump powered by compressed air rather than electricity. Two flexible diaphragms alternately push and pull fluid through the pump, making them safe for flammable liquids and easy to run dry without damage.Ambient Temperature
The temperature of the surrounding environment where a pump is installed or operating. Pumps must be rated for the ambient temperature range of their installation location to avoid performance issues or failure.ANSI Standard
A pump design standard established by the American National Standards Institute that defines dimensional and performance requirements. ANSI pumps are interchangeable between manufacturers, simplifying maintenance and parts replacement.B
Back Pressure
Resistance to flow on the discharge side of a pump, caused by elevation, friction, or downstream equipment. Excessive back pressure reduces pump efficiency and can damage components if not accounted for in system design.Bearing
A mechanical component that supports the rotating shaft of a pump and reduces friction. Bearings must be properly lubricated and maintained to prevent overheating and premature pump failure.BEP (Best Efficiency Point)
The flow rate at which a centrifugal pump operates at its highest efficiency. Running a pump at or near its BEP extends equipment life, reduces energy consumption, and minimizes vibration and heat.Booster Pump
A pump used to increase pressure in a fluid system, typically installed inline when the existing pressure is insufficient for the application. Common in water supply, irrigation, and industrial process systems.Bypass Valve
A valve that allows fluid to be redirected around a pump or component when pressure exceeds a set limit. It protects the pump and system from overpressure damage.C
Cavitation
A damaging condition where low pressure inside a pump causes dissolved gases in the fluid to form and collapse as bubbles. This creates intense shock waves that erode pump impellers and casings over time.Centrifugal Pump
The most common pump type, which uses a rotating impeller to generate velocity in a fluid and convert it to pressure. Best suited for high flow, low viscosity applications like water, chemicals, and light oils.Check Valve
A one-way valve that prevents fluid from flowing backward through a pipe or pump. Essential in systems where backflow could damage equipment or contaminate the fluid source.Chemical Compatibility
The ability of pump materials (seals, impellers, housing) to resist degradation when in contact with specific fluids. Selecting chemically compatible materials is critical when pumping corrosive or reactive chemicals.Corrosion Resistance
A material's ability to withstand chemical attack from the fluid being pumped or the surrounding environment. Stainless steel, PTFE, and certain plastics are commonly used for their corrosion-resistant properties.D
Deadhead
A condition where a pump operates with no flow — the discharge is blocked or closed. Most centrifugal pumps will overheat if deadheaded for extended periods, while positive displacement pumps can generate dangerously high pressures.Diaphragm Pump
A positive displacement pump that uses a flexible membrane (diaphragm) to move fluid. These pumps can handle viscous, abrasive, or chemically aggressive fluids and are self-priming.Discharge
The outlet side of a pump where pressurized fluid exits. Discharge pressure is the pressure the pump generates on the output side of the system.Drum Pump
A portable pump designed to transfer fluids directly from drums, barrels, or IBCs. Drum pumps typically consist of a motor, tube, and impeller and are used for chemical transfer and dispensing applications.Dynamic Seal
A sealing mechanism that prevents fluid leakage where rotating components (like a shaft) meet stationary ones. Mechanical seals and packing glands are common types of dynamic seals in pumps.E
Efficiency
The ratio of useful output power (hydraulic power delivered to the fluid) to input power consumed by the pump motor. Higher efficiency means less energy wasted as heat and lower operating costs.Elastomer
A flexible, rubber-like material used for pump seals, diaphragms, and gaskets. Common elastomers include Buna-N (Nitrile), EPDM, Viton, and Neoprene, each suited to different chemical and temperature conditions.EPDM
Ethylene Propylene Diene Monomer, a synthetic rubber commonly used for pump seals and diaphragms. EPDM offers excellent resistance to water, steam, and many chemicals, but is not suitable for petroleum-based fluids.F
Flow Rate
The volume of fluid a pump moves per unit of time, typically expressed in gallons per minute (GPM) or liters per minute (LPM). Matching flow rate to system requirements is essential for proper pump selection.Fluid Viscosity
A measure of a fluid's resistance to flow — essentially how thick it is. Water has low viscosity, while honey or oil has high viscosity. Pump selection and sizing must account for fluid viscosity.Foot Valve
A check valve installed at the bottom of a suction pipe to keep the pump primed and prevent backflow when the pump is not running. Common in centrifugal pump installations.G
Gear Pump
A positive displacement pump that uses interlocking gears to move fluid. Gear pumps are ideal for high-viscosity fluids like oils, resins, and adhesives, and deliver a smooth, continuous flow.GPM (Gallons Per Minute)
A standard unit of flow rate measurement in the United States. GPM indicates how many gallons of fluid a pump can move in one minute under specified conditions.Graco
A leading manufacturer of fluid handling equipment including pumps, sprayers, and dispensing systems. Graco products are widely used in industrial, construction, and automotive applications.Grundfos
A global pump manufacturer known for high-efficiency centrifugal and submersible pumps used in water supply, HVAC, wastewater, and industrial process applications.H
Head
A measure of pump pressure expressed as the height of fluid the pump can raise. Total head accounts for elevation, friction losses, and pressure requirements throughout the system.Horsepower (HP)
A unit of power used to rate pump motors. Higher horsepower motors can drive pumps at greater flow rates or pressures, but require more electrical energy to operate.Hydraulic
Relating to fluid mechanics and the use of liquids under pressure to transmit force or motion. Hydraulic pumps generate the pressure needed to operate hydraulic systems.I
Impeller
The rotating component inside a centrifugal pump that imparts velocity to the fluid. Impeller design, size, and material significantly affect pump performance and chemical compatibility.Injection Pump
A metering pump designed to inject precise quantities of a chemical into a fluid stream. Common in water treatment, agriculture, and industrial processes for dosing disinfectants, scale inhibitors, or nutrients.Iwaki
A Japanese pump manufacturer specializing in magnetic drive and centrifugal pumps for handling corrosive and high-purity fluids in semiconductor, chemical, and laboratory applications.L
LMI
A brand of metering pumps used for precise chemical dosing in water treatment and industrial applications. LMI pumps are known for reliability and ease of maintenance.Lobe Pump
A positive displacement pump using two or more lobed rotors that mesh to move fluid. Lobe pumps handle viscous, shear-sensitive, or sanitary fluids with minimal product degradation.M
Magnetic Drive Pump
A sealless pump that uses magnetic coupling to transmit torque from the motor to the impeller without a mechanical shaft seal. Eliminates leakage risk, making them ideal for hazardous or corrosive chemicals.Mechanical Seal
A device that prevents fluid from leaking along the rotating shaft of a pump. Mechanical seals use two precision-ground faces — one rotating, one stationary — held together under spring tension.Metering Pump
A precision pump that delivers an exact, controllable volume of fluid per stroke or revolution. Used for chemical dosing, water treatment, and laboratory applications where accuracy is critical.MTBF (Mean Time Between Failures)
A reliability metric indicating the average operating time between pump failures. Higher MTBF values indicate a more reliable pump, which translates to lower maintenance costs and less downtime.N
Neptune
A manufacturer of metering and mixing pumps for chemical dosing in water treatment, industrial, and agricultural applications. Known for durable, high-accuracy positive displacement designs.Net Positive Suction Head (NPSH)
A measure of the pressure available at the pump inlet versus the pressure required to avoid cavitation. Systems must provide sufficient NPSHA (available) to meet the pump's NPSHR (required) for safe operation.O
O-Ring
A circular rubber seal used to prevent fluid leakage at connections, covers, and fittings. O-rings must be compatible with the fluid being pumped and the operating temperature range.P
Peristaltic Pump
A pump that moves fluid by squeezing a flexible tube with rollers or shoes. The fluid contacts only the tubing, making peristaltic pumps ideal for sterile, abrasive, or chemically aggressive fluids.pH
A scale from 0 to 14 measuring how acidic or alkaline a fluid is. Pump materials must be selected based on the pH of the fluid to prevent corrosion — low pH (acidic) and high pH (alkaline) fluids require different materials.Positive Displacement Pump
A pump that moves a fixed volume of fluid with each cycle, regardless of discharge pressure. Types include diaphragm, gear, lobe, and peristaltic pumps. Ideal for viscous fluids and precise metering applications.Pressure Drop
The reduction in fluid pressure as it flows through pipes, valves, and fittings due to friction and resistance. Calculating pressure drop is essential for proper pump sizing and system design.Prime (Self-Priming)
The process of filling a pump and suction line with fluid before startup. Self-priming pumps can evacuate air from the suction line automatically, eliminating the need for manual priming.PTFE (Polytetrafluoroethylene)
Commonly known as Teflon, PTFE is an extremely chemically resistant material used for pump seals, diaphragms, and linings. It handles nearly all chemicals and is FDA-approved for food and pharmaceutical use.Pump Curve
A graph showing a centrifugal pump's performance characteristics — typically flow rate vs. head — at a given speed. Pump curves are used during selection to match the pump to the system's requirements.R
RPM (Revolutions Per Minute)
The rotational speed of a pump's impeller or rotor. Pump performance — including flow rate and pressure — changes with RPM, and operating outside the rated speed range can damage the pump.S
Sanitary Pump
A pump designed to meet hygienic standards for food, beverage, dairy, or pharmaceutical applications. Sanitary pumps use smooth, crevice-free surfaces and FDA-approved materials to prevent contamination.Seal-less Pump
A pump without a traditional mechanical shaft seal, using magnetic drive or canned motor technology to eliminate leakage paths. Ideal for toxic, valuable, or ultrapure fluids where any leakage is unacceptable.Self-Priming Pump
A centrifugal pump capable of evacuating air from its suction line and priming itself without manual intervention. Useful in applications where the pump is installed above the fluid source.Slurry
A mixture of solid particles suspended in a liquid. Slurry pumping requires special wear-resistant pump materials and designs to handle the abrasive nature of the mixture.Specific Gravity
The ratio of a fluid's density to the density of water. Fluids with specific gravity greater than 1 are denser than water and require more pump power; those less than 1 are lighter.Strainer
A device installed on the suction side of a pump to filter out debris and solids that could damage the pump internals. Regular strainer cleaning is essential for maintaining pump performance.Submersible Pump
A pump designed to operate while fully submerged in the fluid being pumped. Submersible pumps are used in sumps, wells, wastewater pits, and other below-grade applications.Suction Lift
The vertical distance between the fluid source and the pump inlet. Most centrifugal pumps have a practical suction lift limit — exceeding it causes cavitation or loss of prime.Surge Suppressor
A device installed in a pump system to absorb pressure spikes and water hammer caused by rapid pump starts, stops, or valve closures. Protects piping, fittings, and pump components from damage.T
Throttling
Restricting flow through a valve or orifice to reduce flow rate or pressure. Throttling a centrifugal pump on the discharge side is a common but energy-inefficient way to control flow.Total Dynamic Head (TDH)
The total pressure a pump must overcome to move fluid through a system, accounting for elevation change, friction losses, and velocity head. TDH is the key parameter used to select the right pump for a system.Turbine Pump
A vertical pump with a multi-stage design used to lift water from deep wells or sumps. Turbine pumps deliver high pressure and are commonly used in municipal water supply and irrigation systems.U
Utility Pump
A general-purpose, portable pump used for light-duty fluid transfer, dewatering, or sump drainage. Utility pumps are typically inexpensive, easy to use, and require minimal maintenance.V
Variable Frequency Drive (VFD)
An electronic device that controls motor speed by varying the frequency of the electrical supply. VFDs allow pump speed — and therefore flow rate — to be adjusted without throttling, saving significant energy.Viscosity
A fluid's resistance to flow. High-viscosity fluids like heavy oils and resins require positive displacement pumps, while low-viscosity fluids like water are well-suited to centrifugal pumps.Viton (FKM)
A fluorocarbon elastomer known for exceptional resistance to petroleum-based fluids, oils, and many solvents. Commonly used for pump seals and O-rings in chemical and fuel handling applications.Volute
The spiral-shaped casing around a centrifugal pump impeller that converts fluid velocity into pressure. The shape of the volute is carefully designed to minimize turbulence and energy loss.W
Walchem
A manufacturer of metering pumps and electronic controllers for precise chemical dosing in water and wastewater treatment applications. Known for their digital control and easy programming features.Water Hammer
A pressure surge or shockwave caused by a sudden change in fluid velocity — typically when a valve closes quickly or a pump stops suddenly. Water hammer can damage pipes, fittings, and pump components.Wear Ring
A replaceable component in centrifugal pumps that maintains the clearance between the impeller and casing. As wear rings degrade, pump efficiency decreases; they can be replaced to restore performance.Wilden
A leading brand of air-operated double diaphragm (AODD) pumps used in chemical processing, food production, mining, and wastewater treatment. Known for reliability in handling abrasive and corrosive fluids.X
Xylem Goulds
A global pump manufacturer producing centrifugal, submersible, and vertical turbine pumps for water, wastewater, industrial, and commercial HVAC applications.Y
Yamada
A Japanese manufacturer of AODD pumps known for lightweight construction and reliable performance in chemical transfer, paint, and coating applications.Z