A Short Glossary Of Pump Industry Terms
This guide will help you know your head from your flow when looking into the pump industry.
· BEP (best efficiency point): The kinetic energy produced by a pump is never converted to pressure energy with 100% efficiency. Friction in the seals/bearings, friction of the pumped fluid over the impeller, and other factors contribute to losses. The BEP is the pump’s volumetric flow rate, designed to convert the most kinetic energy into pressure energy.
· BHP (brake horsepower): An engine’s horsepower before the loss of power caused by any load like a gearbox, etc. It is measured by attaching the engine’s shaft to a “Prony brake.”
· Cavitate: The formation of cavities (bubbles) in fluid flow applications in low-pressure areas, resulting in a collapse in the pump’s high-pressure area and loss of capacity, excessive noise, and possibly damage.
· Efficiency: Calculated by dividing the measured power out of a piece of equipment by the power produced and presented as a percentage.
· Flooded suction: This occurs when the pump is located beneath the liquid source, and the suction is fed by gravity. For centrifugal pumps, this is the preferred method.
· Flow: The measurement of a pump’s liquid volume capacity. It is commonly expressed in litres per minute (L/min), litres per second (L/sec), and metres3 per hour (m3/hr).
· Friction head: The force or pressure necessary to overcome friction caused solely by the inside of a system’s pipes/fittings/pumps.
· Head: The energy stored in a fluid due to the pressure applied to its container. It is measured as a length of fluid where a standard of 10 m equals one atmosphere (14.7 psi).
· Impeller: A device attached to a rotating shaft that converts motion energy into the fluid being pumped.
· NPSHA: The available net positive suction head, which can be used to prevent cavitation within the pump. Defined as static head plus surface pressure head minus process fluid vapour pressure minus friction loss due to piping, valves, and fittings.
· NPSHR: Net positive suction head required to prevent cavitation in a pump.
· Performance curve: A graph that shows the relationship between total head and flow rate for a specific pump with a specific impeller and set of characteristics.
· Pipe friction loss: The loss in head caused by friction between the process fluid and the pipe and joint walls.
· Pressure drop: The difference in pressure between two areas of a pump or the inside and outside of a container.
· Pressure: The ratio of a force to the area over which the force is applied, usually expressed in psi or kPa.
· Specific gravity (SG): The ratio of a substance’s density to the density of a reference, typically water at 4°C.
· Specific speed: A dimensionless number used to characterise turbomachinery. Impellers are normalised to a speed in revolutions per minute equal to that of a geometrically similar impeller delivering three litres per minute against 30 centimetres of hydraulic head.
· Suction static head: The height difference between the inlet reservoir’s surface and the pump’s centre line. Pressure is also included if the tank is pressurised.
· Suction static lift: This only happens when the pump is above the inlet reservoir.
· Total head: The sum of the pump’s output heads. It is calculated by subtracting the suction and discharge heads.
· Viscosity: A fluid’s resistance to gradual deformation caused by shear or tensile stress.
Contact Ernest Electro Engineering for details
Ernest Electro Engineering is a leader in the local pump industry and has a great selection of pumps. We’ll be happy to recommend the right pump for your needs, and if you want to know more about our offers on pumps, contact one of our representatives today. If you would like to learn more about the pump industry and our other offers and solutions, feel free to continue browsing our website for details.