Tip: Use Control+F on a PC or Apple+F on a Mac, to search for specific words or phrases in the glossary.

2 Wire Decoder System

Works with 24 VAC lawn controller's start/stop command to facilitate the electrical path from the breaker box to the pump motor.

2 Wire Water well Motor

Motor which has own starting circuitry built into the motor, which is suspended off the bottom of the pump. The pump must be pulled out of the well to replace the start circuitry.

Absolute Pressure

Atmospheric pressure added to gauge pressure.


Rate at which velocity increases.


Connects the dry (power) end to the wet end of a pump.

Air Lock

An air bubble caught in a pump or pipework that prevents the flow of water.


Centerline of the pump is aligned to the drive shaft of a pump motor.

Ambient Compensated

Environmental conditions around an operating system to be considered during planning.

Ambient Heat

The heat where the equipment is located.

Ambient Pressure

The pressure where the equipment is located.


Also known as current or Coulombs, it is the amount of electrical energy flowing through an appliance at any time, measured in amperes (amps).

Amperes (Amps)

Measurement of electrical energy flowing through an appliance.


Equipment that can work on land and submersed in water.


Description of the conditions in which the equipment must operate in.


American Society of Mechanical Engineers

Atmospheric Pressure

Pressure produced by Earth's atmosphere measured in PSI (Pounds per square inch), at sea level pressure is measured at 14.7 PSI


American Water Works Association

ANSI Process Pump

Horizontal, end suction, single stage pump with dimensionally standard sizes. Used in transfer and process applications for many type of industrial and manufacturing applications.

API Process Pump

Pump built to API 610 standard for use in industrial applications

Auger Pump

Pump that raises water by means of helical impellers in the pump casing. Used in irrigation and dewatering applications.

Axial Flow Pump

Also known as propeller pump, pump that is very high flow, low head. Used in dewatering, circulating and irrigation applications.

Back Flow

Occurs when water flows in reverse within the piping.

Back Plate

Used in some centrifugal pumps to positions the stuffing box and provide the impeller with a wear surface.

Back to back double seal

Rotating seals are facing opposite directions. Worst configuration.

Backflow Prevention Device

Used to prevent the flow of water from the system back to the pump/watersource.

Ball bearing

Consists of an inner race, an outer race and a series of balls between them.

Ball Valve

Contains a spherical disk in order to control flow.


Metric term for on atmosphere of pressure

Base Plate

Piece of material that the pump and motor is connected to.

Basket Strainer

A filter usually containing a type of mesh in order to filter certain particulates out of a fluid.


Supports the rotating shaft and allows it to turn with minimal friction.

Bearing - Sealed

Designed bearing that requires little or no additional lubrication. See owner's manual.

Bearing Lubrication

Grease used for lubriation, which allos for smooth continuous operation of equipment, with only mild wear, and without excessive stress or seizure at the bearings. Consult owners manual for information.

Best Efficiency Point

The point where the power coming out of the pump is closest to the power coming into the pump.

Booster Pump

A pump that adds pressure to the existing pressure of a system.

Booster Pump system

A system intended to add pressure to an existing system.

Booster Station

A pumping sytem used to increase the pressure in a system


Momentarily supplying power to a pump to determine impeller rotation.

Butterfly Valve

Employing a metal disk, this valve can restrict flow or completely stop flow.

Booster Pump

This pump is used to boost the pressure in a system.

Cam Coupling (Fitting)

Connection fitting which allows a quick hook-up and removal of hose at a pump or other connection point.


Strorage device for electrical energy

Capacitor Start Motor

Motor in which a capacitor is in series with the start winding.

Capacity (Flow Rate)

The amount of water a pump will put out or a tank will hold.


A compound that is formed when carbon combines with an element creating a very hard metal often used as a mechanical seal face


An effect that results in residue affecting the movement of mechanical seals.


The pump reservoir in which a fluid enters in the intake and then exits through the discharge.


Bubbles form in areas of low pressure in fluid being pushed through a pump, the bubbles implode causing damage to the impeller.

Cavitation Damage

The pitting or wearing away of the impeller caused by the collapsing of bubbles in the pump.

Centrifugal Force

Fluid is forced from the center of the impeller outwards.

Centrifugal Pump

A type of kinetic pump that employs centrifugal force to move water.

Centrifugal Switch

Within a motor, an electric switch that operates using centrifugal force created from a rotating shaft which disconnects the start windings after reaching operating speed.


A hard, chemically inert seal face material.

Check Valve

These valves only allow for a one way flow of liquid, entering at one end and exiting at the other.

Chemical Feeder

A device used to introduce chemicals into something else.

Circuit Breaker

An automatic device for stopping the flow of current in an electric circuit as a safety measure.


Waterproof receptacle for holding liquids.

Clear Water

Rain water runoff collected in a sump or collection basin.

Closed Impeller

These impellers are designed to have enclosed veins which increases the velocity of the liquid moving through the pump resulting in higher head.


In mechanical face seals, this refers to a non-metallic material or a combination of non-metallic inserted into a metal holder

Continuous Duty Design

A design specification that allows motors to run for long periods of time through heat dispersement.

Control Box

A device that contains electrical components and are used to control irrigation systems

Corrosion Resistant

Corrodes at a rate of .002 inches per year.


The movement of an electrical charge, matter, carried by electrons along a path (conductor, wire). Current is measured in terms of amperes (amps).


This happens when a pump repeatedly turns on and off, which can damage the pump.

Canned Motor Pumps

A seal less centrifugal pump, with an impeller that is attached to the motor rotor. Used in chemical or high temperature pump applications.

Circulator Pump

Pump that is used in HVAC systems in buildings circulating all temperatures of water.

Concrete Pump

A concrete pump is designed to pump concrete and other mixed aggregate solutions.

Cryogenic Pump

Used in applications where the liquid is at a very low temperature.

D.I.N. Standard

The German standard for industrial products.

Dead Head

The point on a pump performance curve where the unit is pumping zero GPM.

Deep Well Jet Pump

A pump that can lift water less than 70'.

Deep Well Submersible Pump

Pumps that can be submersed around 1000' feet.


A measure of the weight of fluid.


Removing water areas that you don't want water in.


Portion of a volute case from the cutwater to the pump flange.


The pump orifice where water exits the pump.

Discharge Head

The total head, including static head and friction head, on the discharge side of the pump.


The straight line seperation between an object and a reference point.

Double Suction Pump

The rotor is suspended between bearings with the fluid entering on either side of the impeller. Used at higher capacities.


The difference between the static water level and the pumping water level in a well.

Drawdown Level

The water level in a well measured while the pump is pumping at full capacity.

Dry End

The mtor end of the pump.

Dry Running

Running the pump without fluid at the seal face.

Dual Seal

Two seals running in various configurations.


The property of a metal that lets you give it a great deal of mechanical deformaiton without cracking.

Dynamic (System) Head

The pump head created by friction in the system.

Dynamic Elastomer

The rubber part that has to move or flex to compensate for seal face wear or shaft movement.

Deep Well Jet Pump

Uses a venturi, which becomes a second pump that charges the above ground unit, to increase pressure.

Deep Well Submersible Pump

Pump that can be submersed up to 1000's of feet.

Diaphragm Pump

Reciprocating positive displacement pump used where the fluid has high solids or high viscosity.

Double Suction Pump (horizontal split case)

The rotor is suspended between bearings with the fluid entering on either side of the impeller.

Drum Pump

This slim pump is used to move small quantities of liquids out of drums and carboys.


Environmental Protection Agency

E.P.R. (Ethylene Propylene Rubber)

The most common elastomer used in the sealing of water based higher pH materials, but cannot be used in petroleum products.

Effective Diameter

The calculated diameter where the pressure penetrates between the metal plats. This number is used to determine the hydraulic balance diameter of the seal face.


Power out of the equipment divided by the power in.


Sewage or waste water which has undergone some pretreatment.

Elastic Range

The stressed part retains its memory and returns to its original shape.


A rubber like material that, when compresed and then released will return 90% of its original shape in less than five seconds.

Electrical Disconnect Switch

A manually operated, external switch that is used to make sure that an electrical circuit can safely be completely de-energized.

Electrical Ground

Circuits connected to the ground to protect the user.

Electrical Phase (motor nameplate reference)

Usually motors are run on either single or three phase. Consult power company for availability of power.

Electrical Relay

A switch operated by electricity. Can be controlled using low power and can control multiple loads.


The vertical distance that a fluid must travel from the pump to the highest point in the discharge system.

Endurance Limit

Beyond this point the metal will fatigue without increasing the stress.

Energy Driven Pump

A type of pump which uses an electric or hydraulic motor as its driver or motive force.

EPDM (Ethylene Propylene Diene Monomer)

Elastomer characterized by a wide range of applications.

Extended Duty Design

Designed for long-term intermittent use. (Not continuous duty use)

Eye of the Impeller

The center of the impeller, where the fluid enters.

Effluent Pump

A pump used in sanitary sump drainage and grey water applications. Usually pump smaller solids than a sewage pump.

End Suction Pump

Flow enters the end of the casing and is pushed out of the top, used to transfer or circulate liquid. This is not a self priming pump and requires a foot valve.

Face Lubrication

The fluid or vapor that sometimes exists between lapped mechanical seal faces.

Face Pressure

The sum of all the loads on the seal face divided by the area of the seal face.

Face to Face Seals

Two seals running against a common seal face.


A device used to remove solid particls from a fluid, removing smaller particles than a strainer.


A device used to couple to a pipe on the suction or discharge of a pump.

Float Control - see float switch

Float Switch

A device used to detect the level of liquid within a tank.

Flow Control Valve

A device that requlates the flow or presure of a liquid.

Flow Sleeve

A sleeve attached to a submersible pump to force liquid to pass around it and enter the pump's suction intake from below to water cool the motor.

Flow Switch

A device designed to monitor fluid flow in a pipe.


A substance that can either be a liquid or a gas.


Supports the wet and power end of the pump and attaches it to the base plate.

Foot Valve

Use to prevent debris from entering the pump or pipe and to prevent back flow.


An applied effort that tends to attempt to move something.

Francis Vane Impeller

Most popular impeller shape with a specific speed between 1500 and 4000.


The reistance to motion of two objects or surfaces that touch.

Friction Loss

The loss of pressure or head due to resistance to flow in the pip and fittings.

Friction Loss Calculations

Based on the type of pipe used, the size of the pipe, the average flow rate, and the length of the pipe.

Friction Loss Charts

Table showing resistance to water movement within various types of piping material.

Full Load Amps (FLA)

This is the rating on the motor nameplate. The FLA is the amperate rating at the motor nameplate horsepower rating and at its rated (nominal) voltage. This is usually the point of maximum efficiency and maximum power factor for the motor. This is where the motor prefers to run.

Full Port Ball Valve

A valve that allows for full pipe size flow, no friction loss, when in the open position.


A safety device utilizing a thin strip of metal that will melt and break an electric current if the current exceeds a safe level.

Fire Pump

Centrifugal pump, employing high pressure, used for fire fighting.

Flexible Impeller Pump

Type of rotary displacement pump that has a rotating rubber impeller with vanes that bend then straighten as the impeller rotates to conform to the internal cam in the pump casing. Used in marine services.

Gallons Per Day (GPD)

Flow rate measurement.

Gallons Per Hour (GPH)

Flow rate measurement.

Gallons Per Minute (GPM)

Flow rate measurement.


A plastic or rubber ring or flat plastic or paper device used in machinery as a seal against air, oil, or high pressure.

Gate Valve

This valve opens and closes by lifting or dropping a gate or wedge.


A measurment instrument, some uses include measuring PSI.

Globe Valve

A valve used to regulate flow in a pipeline, utilizing a movable disk.


A device that maintains a constant engine speed; a spring loaded device which is mounted under the canopy on the motor shaft designed to regulate rotational spped or momentum.

Gray Water

Non-toilet household wastewater that is sometimes recycled expecially for use in gardening or for flushing toilets.

Grease Seal (Lip Seal)

A spring loaded elastomer seal commonly used to seal bearing. Sometimes called a "lip seal".

Grinder Pump

A sewage pump designed to chop or cut solids into smaller pieces.

Ground Water

The water that systems pump and treat from aquifers.

Gear Pump

Rotary displacement pump in which liquid is passed between two meshing gears and the surrounding casing. Used for clean oils and other viscous liquids.

Grinder Pump

A sewage pump designed to chop or cut solids into smaller pieces.

"High Voltage" (motor nameplate reference)

The highest voltage a motor can use to run. Running a motor on high voltage may increase the amperage draw and heat of the motor, while decreasing the life of the motor.


A toggle switch which allows you to choose how you want the pump to run. Auto allows flow switches to turn the pump on or off, while hand allows for manual on/off.

Hard Face

A seal face either rotating or stationary, must be a wider seal face.

Head in Feet

A term used to define water pressure in vertical feet.

Hertz (HZ)

One cycle of AC electric flow.

Horse Power

One horsepower' is defined as the ability to move 33,000 pounds one foot in a minute. It is a measure of the work performed.

Hose Connector

The fitting used to connect the hose to the wall or pump fitting.

Hydraulic Shock

A damaging condition that occurs when a column of liquid changes direction quickly and increases in velocity. Also known as water hammer.

Horizontal Split Pump

Centrifugal pumps that has a single double suction impeller supported between two bearings. Used in higher flow applications.

Hydraulic Ram Pump

Cyclic water pump power by hydropower, using the water hammer effect to develop pressure that allows a portion of the input water that powers the pump to be lifted to a point that is higher than where the water originally was. Used for pumping water to an elevation higher than the water source. Requires no outside source of power.


International standards organization. Sets pump and seal standards for the metric community.


Attaches to the end of the shaft to impart energy the fluid being pumped. Available in open, semi-open and closed designs.

Impeller Eye

The center of the impeller or where fluid enters the impeller.

Impeller Vane

Located between the eye and the discharge side of the impeller. Directs the flow of the liquid to the outside diameter of the impeller.


Occurs when a material collapses in on itself, releasing stored energy in the molecules, causing damage to a pump. (Cavitation)


The fitting through which water passes through.

Jammed Impeller

Occurs when some type of debris is pulled into the suction port that stops motor rotation.

Jet Pump

A centrifugal pump with a jet attached, either at the pump (shallow well) or in the well (deep well).


A metric unit for the measurement of heat. Defind as the energy required to move one Newton over one meter.

Jet Pump

A centrifugal pump with a venturi attached, either at the pump (shallow well) or in the well (deep well).


One thousand watts. The normal unit for work in the metric system.

"Low Voltage" (motor nameplate reference)

The lowest voltage a motor can use. Will cause either the current or the amps to increase to compensate for the low voltage, causing the motor to heat up and decreases the life of the motor.


The height that a water must be pushed through a system.

Lip Seal (Grease seal)

A spring loaded elastomer seal commonly used to seal bearing. Sometimes called a "lip seal".

Liquid Level Control

General term given to any device that monitors the height change of liquid that can send a start/stop or warning signal to a separate electrical device.

Liquid Level Probes

An electrical device that detects the level of liquid within a tank.

Low Flow

A condition that can cause excessive heat inside the pump volute.


Any fluid that will maintain a film thickness of one micron or more at its operating temperature and load.

Lobe Pump

Employs two shaft drive lobes which mesh with each other, but do not touch due to the use of timing gears. Used for food, beverage, pharmaceutical and biotech applications.

Mechanical Groove Fitting

Components of a pipe joining system where a bolted coupling and gasket use grooves to join different parts together.

Mechanical Seal

A positive sealing device used to seal all fluids.

Minimum Flow

A condition that can cause excessive head inside the pump volute.

Mixed Flow Pump

Functions as a compromise between radial and axial flow pumps, the fluid experiences both radial acceleration and life and exits the impeller somewhere between 0-90 degrees from the axial acceleration.

Motor Bearings

Supports both ends of the motor shaft allowing it to rotate smoothly with a minimum of friction and wear.

Multistage Pump

A pump that utilizes multiple impellers, sometimes to boost pressure or increase the depth of a deep well pump.

Magnetic Drive Pump

A seal less centrifugal pump transmitting torque from the motor to the impeller using a rotating outer magnet which transmits the magnetic flux through a can to an inner magnet that is attached to the impeller. Used for pumping chemicals, hydrocarbons or other liquids difficult to seal.

Metering pump

Type of reciprocating positive displacement diaphragm pump that has a very low flow rate. Used to meter low doses with high accuracy, for chemical treatment applications.

Mixed Flow Pump

Functions as a compromise between radial and axial flow pumps, the fluid experiences both radial acceleration and life and exits the impeller somewhere between 0-90 degrees from the axial acceleration.

Multistage Pump

A pump that utilizes multiple impellers, sometimes to boost pressure or increase the depth of a deep well pump.


Net Positive Suction Head - static pressure on the suction side of the pump, must be high enough to prevent the water entering the impeller from boiling.


Net Positive Suction Head Available is the amount of head available to overcome the NPSHR.


Net Positive Suction Head Required is the amount of head required by the pump to keep the liquid being pump in a liquid state.

NBR (Nitril Rubber)

Synthetic Rubber that is resistant to oil, fuel and other chemicals.


National Electrical Code is a standard for the safe installation of electrical wiring and equipment in the United States.


National Electrical Manufacturers Association is the association of electrical equipment and medical imaging manufactureres in the United States.


General-purpose electrical enclosure. Protects against dust, light and indirect splashing; primarily prevents contact with live parts. Used indoors and under normal atmospheric conditions.


Electrical enclosure intended for outdoor use. Mainly used in the irrigation industry to protect electrial components from falling rain and ice formation.


Watertight (weatherproof) electrical enclosure used outdoors. Used for industrial applications; employing gaskets to protect against wind-driven or directed water, dust, or particle entry.


An ejector part/device that increase the velocity of the liquid flowing through it by creating a partial vacuum at its throat.

O-Ring Groove

The space into which an O-ring is inserted.


Original equipment manufacturer. The pump or seal company, not the distributor of the products.

Ohms Meter

Device used to check the resistance of the flow of electricity.

Oil Life

Lubricating oil has a useful life of about thirty years at thirty degrees centrigrade if it is not contaminated.

Open Impeller

Impellers deisgned with oprn blades or veins. This impeller works vest when unrestricted.


Occupation and Safety Health Administration is a federal agency of the United States that regulates workplace safety and health.


An extremely oxidizing agent and bacteriocide, which consists of three oxygen atoms.

Parallel Operation

The pumps are discharging to a common header.


Allowing some material to pass through.


A measurement of water acidity or alkilinity using a scale of 0-14. 7 is neutral, below 7 is acidic, above 7 is alkalinity.

Pipe Strain

The strain on the pump volute caused by the piping. It will cause excessive mechanical seal movement and can cause contact between rotating and stationary pump and seal components.


Surface voids caused by corrosion, erosion or cavitation.


A chemical compound with many repeating structural units.

Potable Water

Any water, such as an approved domestic water supply, which is bacteriologically safe and otherwise suitable for drinking.


The effect produced by the application of force over the surface of an enclosed area.

Pressure Drop

The decrease of hydrostatic force due to the effects of friction or restrictions on a flowing liquid.

Pressure Gradient

The pressure drop between the seal faces.

Pressure Head

The pump head exerted by atmospheric pressure or any additional pressure that might be in the vessel.

Pressure Sensor

A device that measures the pressure of a gas or liquid.

Pressure Switch

Electrical/pneumatic device used to turn the pump on and off.


Filling the pump case to remove any trapped air in the system.


A type of fan that converts energy into thrust.


Pounds per square inch.


Converts mechanical energy into hydraulic energy.

Pump Curve

A diagram supplied by the pump manufacture to describe the relationship between the head and the capacity of a particular pump using various size impellers.

Pump Efficiency

The ratio or water power to the shaft power.

Pump Hat

Small cover for protecting the pump motor from the elements while providing shade for cooling.


Polyvinyl Chloride. Plastic material widely used in irrigation for pipe and fittings because it is light, inexpensive, easy to assemble and can have a long life.

Peristaltic Pumps

Also known as a hose pump that has a roller or shoe that squeezes a tube or hose as it rotates. Used in applications where solids or corrosive liquids exist.

Piston Pumps

Pumps that employ double acting reciprocating pistons. Used in oil production and high pressure applications.

Plunger Pumps

Pumps that are built with 3 or 5 single acting reciprocating plungers. Used in oil or high pressure applications.

Positive Displacement Pump

This pump does not have impellers, but instead relies on rotating or reciprocating parts that directly push liquid in an enclosed volume, until enough pressure is built up to move the liquid into the discharge system. Used in low flow, high pressure, high viscosity or fragile solid applications.

Progressive Cavity Pump

A type of positive displacement pump that transfers fluid by means of the progress, through the pump, of a sequence of small fixed shape, discrete cavities as the rotor is turned. Applications include: oil, slurry, and sewage pumping.

Rate of Flow (GPM)

The measurement of the volume of flow per unit of time expressed in gallons per minute.

Reduced External Voltage - REV

A wiring configuration assuring any voltage leaving an electrical panel to a float, probe or other device is rated at a safe level of 30v.

Reduced Incoming Amps - RIA

A component configuration that will work with low amperage incoming signals. Will work with all start/stop signal controls - including 2-wire systems.

Relief Valve

A type of valved used to relieve the pressure in a system.


Impedes the flow of electrons, and is measured in Ohms

Rotation Clockwise (CW)

A left to right shaft rotation while facing the shaft end of a motor, or suction tap of a pump.

Rotation Counterclockwise (CCW)

A right to left shaft rotation while facing the shaft end of a motor, or suction tap of a pump. Most pumps run this direction.

Regenerative Turbine Pump

Type of pump in which the fluid takes multiple trips through the vanes of the impeller increasing flow and pressure. Used in boiler feed applications.

Roller Pump

Employs rollers that revolve inside the pump housing to force a liquid through the outlet to the nozzle. Used for agricultural applications and industrial spraying.


Service Factor Amps. A factor indicating the degree to which an electric motor can be operated over the specified horsepower without danger of overloading or failure.

Seal Faces

The lapped faces that that provide the primary sealing in a mechanical seal.

Seal Life

Seals should run leak free until the sacrificial face (usually carbon/ graphite) is worn away.

Self Align

A method of keeping both mechanical seal faces square to the rotating shaft.

Self Priming

The ability to exhaust gasses from a pump case.

Self Priming Pump

a centrifugal pump having the capability of dispersing a certain amount of air from its pump body, assuming the pump has been primed initially, when operating under a suction lift; to free itself of entrained gas without losing prime; and to continue normal pumping operation without attention.

Septic Tank

A container used to collect wastewater from a house. Generally they have two compartments and are watertight. The larger compartment is for the raw sewage and the second compartment for effluent water. The second compartment can also be used as a pump chamber.


Raw wastewater from residential, commercial or industrial sites. Sewage from residential sites is generally defined as 2” or less solids and commercial sites are 3” or 4” solids.

Sewage Pump

A pump designed to pump black water (effluent).

Shallow Well

A type of jet pump OR a well having less than 25' of lift.

Shallow Well Submersible Pump

A type of submersible pump will work up to a depth of around100 feet.

Shallow-Well Jet Pump

A type of pump that will work to a maximum depth of about 25 feet. The jet is either attached or pre-cast into the pump body.

Shut off Head

The total head created by a pump that is running against a closed discharge.

Silica Carbide

Synthetically produced crystalline compound that is incredibly hard - used in pump seals.


A machine that separates debris from the top of the water.


Solids in liquid. It is impossible to define when the quantity and size of the particles becomes too much for the mechanical seal.


A Munro Manufacturing trademarked control panel that offers exceptional pump protection against loss of prime or heat.

Soft Start

Device used to temporarily reduce the load and torque in the powertrain and electrical current surge of the motor during startup.

Solenoid Valve

An automatic valve operating under low voltage (24V AC) which may be remotely located in the landscape and controlled via a signal cable from the central controller (timer).


When one liquid dissolves or mixes with another liquid.

Specific Gravity

Ratio of the weight of a volume of a substance to an equal volume of water.

Stainless Steel

Alloy steels containing a high percentage of chromium.

Start Signal

An electrical signal sent to begin a water cycle. Signal can initiate from a switch, controller, manual operation or other means.


A Munro Manufacturing trademarked control panel that provides pilot duty operation between start signal and pump.

Static Head

The maximum height that a liquid is being pump.


A measure of the amount of deformation produced in a substance when it is stressed.


Any device used to sift debris from inlet of pipework.


A measure of the intensity of the load applied to a material.

Stress Relieve

To take residual stress out of an object. This is very important with lapped seal faces; especially those that have been inserted into a metal holder.

Submersible Pump

A multi-stage centrifugal pump with a waterproof electric motor mounted below the pump end.

Suction Head

The head on the suction side of the pump. You subtract it from the discharge head to determine the head being produced by the pump. It is a sum of the static, pressure and friction heads.

Suction Leak

An escape of liquid from, or insertion of air into, the piping system going into a pump.

Suction Lift

The condition where the water supply is below the pump.

Suction Side (of a pump)

The side of the pump where the inlet is located.


A low space that collect liquids such as water or chemicals.

System Capacity

The ability of an irrigation system to deliver water to an acreage.

System Curve

A description of what the pump is required to perform. The pump will pump where the system curve intersects the pump curve.

System Head

The head caused by friction in the piping. valves and fittings.

Sand Pump

A type of plunger pump that removes chopped-up drill core from a drill hole.

Screw Pumps

Built with two intermeshing screws, driven by timing gears these pumps are used in fuel transfer, and other applications requiring high flow rates of viscous liquids.

Self Priming Pump

A centrifugal pump having the capability of dispersing a certain amount of air from its pump body, assuming the pump has been primed initially, when operating under a suction lift; to free itself of entrained gas without losing prime; and to continue normal pumping operation without attention.

Sewage Pump

A pump designed to pump raw sewage water.

Shallow-Well Jet Pump

A type of pump that will work to a maximum depth of about 25 feet. The water return through a venturi orifice is either attached or pre-cast into the pump body to assist with lift. See Jet Pump

Single stage Submersible Pump

A type of submersible pump that will work to a depth of approximately 100 feet.

Slurry Pump

A pump that handles abrasive slurry in mining, procession, dredging and slurry applications.

Spur-gear Pump (Internal Gear)

Utilizing a "gear within a gear" system, the intermeshing gear provides pockets of liquid which rotate and force liquid from the pump. Used in industrial applications to pump fluids such as: fuel, glycol, and asphalt.

Submersible Pump

Pumps with an enclosed motor that are able to be submersed. Used in sump, dewatering and irrigation applications.


Total Discharge Head. A combination of the suction head and the head being produced by the pump.


A steel, plastic, or fibrewound vessel designed to store pressure or water.

Temperature Switch

A device used to monitor the temperature within a pump. If the temperature is too high the pump will turn off, protecting the pump.

Thermal Conductivity

A measure of the material's ability to conduct heat.

Thermal Overload

Over-working equipment causing it to generate heat to the point of damaging itself.

Thermal Overload Protection

Relay used to shut down an overloaded motor before the motor becomes hot enough to cause damage. A bi-metallic heat detection device.

Thermal Protection

A bi-metallic heat detection device that will shut an over-worked motor down before the generated heat causes damage to itself.


A plastic material that can be softened or melted repeatedly without change of properties.

Time Delay

A adjustable timer capable of delaying an action after start signal is received.


A turning or twisting effort that results from a force being applied to a rigid object at a radial distance from the center of rotation.

Torque Arrestor

A device use to prevent the turning and twisting of pipes.

Total Dynamic Head (TDH)

Total height that a fluid is to be pump, taking into account all losses, which include friction loss, pounds per square inch and elevation change.


Attached to the pump and used to send a vibration signal to a meter where it can be read.


A measurement of the amount of suspended solids (colloids) in a solution.

Trash Pump

Self-priming centrifugal designed to handle rocks and other solids, used in dewatering applications.

Utility Pump

An inexpensive pump similar to a sump pump except that it is not automatic.

Utility Pump

A versatile pump similar to a sump pump.

Vane Impeller (Semi-Open)

This has only one shroud. The other side of the impeller is in close contact with the pump volute case. The vanes of the impeller are spaced far enough apart to pass solids.

Vane Passing Syndrome

A type of cavitation caused by the impeller/ cutwater clearance being too small.


The fluid passes from a liquid to a gaseous state. If this happens at the seal faces the seal faces will be blown open.

Variable Frequency Drive

Circuitry that runs a motor from 0 to 60 Hz. Adjusting the power to save energy.

Variable Speed Motor

Used to control flow in a system by varying the frequency of the motor. Recommended for circulating systems and any other system where the main head is friction losses in the piping system.


The measurement of the motion of liquids, expressed in feet per second.

Velocity Head

Part of the total head calculation.


To remove air or gas from the system. It is important to vent the stuffing box in vertical pumps to prevent the seal faces from running dry.


Resistance to deformation by shear force. Example honey has a higher viscosity than water.


An E.I. Dupont Dow manufactured elastomer widely used in the sealing industry. The generic name is fluorocarbon. Many of these compounds are attacked by water and steam.


Volatile Organic Chemical. It is a category of water contaminants.


Electrical force or pressure that causes current to flow in a circuit.

Voltage Imbalance

Difference between the highest and the lowest voltage exceeding 4%.

Volute Casing

A pump component that encloses the impeller and converts the high velocity energy created by the impeller into pressure energy. It is spiral shaped, similar to a snail's shell.

Vortex Impeller

This impeller creates a revolving mass of water which forms a whirlpool. Minimizing the risk of clogging.

Vortex Pump

A type of pump used for excessive solids. The impeller is recessed into the volute. A very low efficiency design, but practical in many applications.

Vortexing Liquid

Creating a "whirlpool affect" that can draw air into the suction of the pump.

Vane Pumps

These pumps employ a rotor with vanes located in slots, rotating inside an eccentrically shaped casing. Used in transferring oils and other viscous liquids.

Vertical Sump Pump

These pumps are built with a vertical shaft supported in a center column. Used in sump applications.

Vertical Turbine Pump

Vertical shaft pump that is designed to fit in a bore-hole well. Used for irrigation and booster applications.

Vortex Pump

A type of pump used for excessive solids. The impeller is recessed into the volute. A very low efficiency design, but practical in many applications.


Designation for parts rated for water, oil and gas.

Water Hammer

A damaging condition that occurs when a column of liquid changes direction quickly and increases in velocity. Also known as hydraulic shock.

Water Horse Power

The energy added by the spinning impeller.


Liquid is forced past the motor so that the heat of the motor can be transferred to the liquid increasing usage time and usable life.


A measurement of electrical power where watts = volts x amps. One watt is the rate of energy expended when a steady current of one amp flows under a pressure of one volt.

Wear Ring

Used with closed impeller pumps to restrict leakage from the high pressure side of the pump to the low pressure side. Should be replaced when the recommended clearance is doubled.

Weep Hole - Nema 3R box

Small opening meant as an outlet for water to escape an electrical box.

Weep Hole - pump

Small opening meant as an outlet for air to escape a pump case to prevent air lock.


A barrier that is designed to alter flow characteristics across rivers and streams.

Well Cap

A tight-fitting, vermin-proof seal designed to prevent contaminants from flowing down inside of the well casing.

Well Casing

The tubular lining of a well. Also a steel or plastic pipe installed during construction to prevent collapse of the well hole.

Wiring Diagram

Shows how the pump is wired for voltage.


Inline strainer that removes unwanted solids from liquid, gas, or steam lines.


A zone is the area to be watered by a single control valve. Zones are ideally comprised of similar sprinkler types and plants with similar water requirements. This term is usually used with domestic sprinkler systems.