Water Gardening Terminology

Capacity Amount pumped in gallons per minute or gallons per hour, etc.

Dual Purpose This versatile pump category is designed to operate either submersed or in-line.

Epoxy Encapsulated (Potted) Pumps featuring a epoxy -encapsulated motor, plastic housing, and radial lip seal on the motor shaft.

Flooded suction / Gravity fed Liquid source is higher than the pump, and liquid flows to the pump by gravity. Recommended for centrifugal pump installations.

Flow The measure of the liquid volume capacity of a pump. Given in GPH (Gallons per Hour) or GPM (Gallons per Minute) as well as LPM (Liters per Minute) and mL/M (milliliters per minute).

FNPT This refers to the female pipe thread, in which the threads are on the inner side on the connection fitting.

Head Another measure of pressure, expressed in feet. Indicates the height of a column of water being lifted by the pump, neglecting friction loss in piping. If pump is submersed, the head can be measured from the surface of the water. Head (feet of water) = PSI x 2.31

Impedence Protected A non-mechanical method of preventing motor overheating. The motor coil is designed to "impede" excess current, resulting in a stabilized motor temperature.

Inlet/Intake Refers to the opening through which water enters the pump head.

In-Line A pump which operates in open air, by connecting tubing to the inlet and discharge outlet.

Lift (Suction Lift) Occurs when the liquid source is lower than the pump. The pumping action creates a partial vacuum and atmospheric pressure forces liquid up to the pump. The theoretical limit of suction lift is 34 feet for water at sea level, but in practical applications it is 25 feet or less, depending on the pump style.

Lip Seal A flexible ring usually rubber or similar material with the inner edge held closely against the rotating shaft by a spring.

MNPT This refers to the male pipe thread, in which the threads are on the outer side on the connection fitting.

Mechanical Seal A two-part seal with one rotating part and one stationary. Touching surfaces on the parts are highly polished and provide excellent sealing capability and life. The surfaces can be damaged by dirt or grit in the liquid.

NPT Refers to the "National Pipe Thread" standard measurement. Outlet/Discharge The opening through which the water exits the pump.

Packing Rings of flexible material (foil, graphite or synthetic fiber) held in the pump stuffing box by a packing gland or nut. Permits adjustable sealing with minimum maintenance.

Permanently Lubricated The oil-filled motor housing design also features a radial lip seal on the motor shaft. They have an exceptional life expectancy, because the oil serves as a continuously lubricate for all the moving parts and the shaft seal. This non-toxic oil, often paired with an aluminum, cast iron, or plastic housing, also helps dissipate the heat build-up found in continuous-running pumps. Therefore the motor stays cool and extends the life of the pump.

Prime The liquid required to begin pumping action.

Seal A device mounted in the pump housing and on the pump shaft to prevent liquid leakage from the pump.

Seal-less No seal is used, power is transmitted from the motor to the pump impeller by magnetic force. An example is Magnetic Drive Aquarium Pumps.

Specific Gravity The ratio of the weight of a given volume of a liquid to the same volume of pure water. Power requirement increases for liquids with specific gravities greater than 1.0.

Submersible A pump which operates only when totally submersed in the fluid which is being pumped, with water-proof electrical connections, using a motor which is cooled by the liquid.

Sump A pit that collects liquid below floor level. Sometimes refers to the waste sump or oil reservoir.

Thermally Protected Mechanical safety device in the motor to prevent overheating.

Total Head The sum of discharge head, suction lift and friction losses.

Viscosity The thickness of a liquid affecting its ability to flow. The more viscous the liquid, the slower the pump speed.

Wet-Rotor (Hysteresis) Often referred to as magnetic drive pumps, utilize an epoxy-encapsulated motor and plastic housing. A permanent magnet is attached to the impeller. The magnet acts as the rotor in a conventional motor. They are seal-less and oil-less.

Questions & Answers

Ask a question about Water Gardening Terminology. Click here
Customer Reviews

About Us Contact Us Customer Reviews Facebook Twitter Disclaimers Privacy Policy Returns Shipping Policy Terms of Sale Terms of Use Warranty FAQ Site Map Technical Info Terminology Troubleshooting
  • Internet prices apply only to Internet purchases.
  • Minimum order amount is $20.00.
  • All merchandise listed is in stock.
  • Orders are shipped the next business day.
  • We only sell within the 48 adjacent United States.
  • Shipping tracking numbers are e-mailed automatically.
  • Office hours are: Mon - Fri, 8am - 4:30pm EST excl. holidays.
Copyright © 2012 All Rights Reserved.