Laboratory Pumps: Liquid Pump Terminology

Knowing the correct terminology for laboratory pumps helps you understand their functionality. Dead head? We’re not talking about a fan of a 70’s jam band. Find the meaning of this and other terms below.

Masterflex® L/S® Precision Modular Drive with Bench Top Controller

Masterflex® L/S® Precision Modular Drive with Bench Top Controller

Cavitation. Process in which small bubbles are formed and implode violently; occurs when NPSHa < NPSHr

Dead Head. The ability of a pump to continue running without damage when discharge is closed off. Only recommended for centrifugal pumps

Density (specific weight of a fluid). Weight per unit volume, often expressed as pounds per cubic foot or grams per cubic centimeter

Discharge Head. The outlet pressure of a pump in operation

Flooded Suction. Liquid flows to pump inlet from an elevated source by means of gravity. Recommended for centrifugal pump installations

Flow. A measure of the liquid volume capacity of a pump. Given in gallons per hour (GPH), gallons per minute (GPM), liters per minute (L/min), or milliliters per minute (mL/min)

Fluids. Include liquids, gases, and mixtures of liquids, solids, and gases

Head. A measure of pressure, expressed in feet of head for centrifugal pumps. Indicates the height of a column of water being moved by the pump (without friction losses)

Pressure. The force exerted on the walls of a tank, pipe, etc., by a liquid (normally measured in pounds per square inch (psi))

Prime. Charge of liquid required to begin pumping action when liquid source is lower than pump. Held in pump by a foot valve on the intake line or by a valve or chamber within the pump

Seals. Devices mounted in the pump housing and/or on the pump shaft that prevent leakage of liquid from the pump.

Self-Priming. Pumps that draw liquid up from below pump inlet (suction lift), as opposed to pumps requiring flooded suction

Shear Rate. The velocity of a liquid per unit distance between two surfaces

Specific Gravity. The ratio of the weight of a given volume of liquid to pure water. Pumping heavy liquids (specific gravity greater than 1.0) will require more drive horsepower

Strainer. A device installed in the inlet of a pump to prevent foreign particles from damaging the internal parts

Sump. A well or pit in which liquids collect below floor level; sometimes refers to an oil or water reservoir

Total Head. Sum of discharge head minus the suction head

Viscosity. The “thickness” of a liquid or its ability to flow—most liquids decrease in viscosity and flow more easily as they get warmer

 

Be the first to comment on "Laboratory Pumps: Liquid Pump Terminology"

Leave a comment

Your email address will not be published.


*


This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: