 CO2 electricity emission factor
This factor allows to calculate the amount of greenhouse gases emitted per unit of electricity produced. The CO2 emission factors vary from country to country. They depend on the specific fuels used to make the energy. Countries that use a high percentage of fossil fuels for electricity production will, in general, have a higher factor than those that use more renewable and nuclear energy.

A term in fluid mechanics to represent the energy stored in a fluid due to the pressure exerted on its container. Measured as a length of fluid where a standard of 10m is equal to one atmosphere, or 14.7 psi.

Flow
The measurement of the liquid volume capacity of a pump. Often given in litres per minute (L/min), litres per second (L/sec) and metres3 an hour (m3/hr).

Flowrate
Flowrate (Q) is the flow (volume of liquid per unit of time) delivered by a pump through the outlet, normally expressed in litres per second (L/s).

Performance curve
A graph depicting the plot of total head vs flow rate for a specific pump, with a specific impeller and set of characteristics.

​Pipe friction loss
The loss in head due to the friction between the process fluid and the walls of the pipes and joints.

The force (pressure) required to overcome the friction that is solely due to the inside of the pipes/fittings/pumps in a system.

The sum of the head produced by the pump. It can be calculated by subtracting the suction head from the discharge head. Also referred to as Total Dynamic Head.

​Pressure
Is the ratio of a force over an area over which the force is applied. Often measured in psi or kPa.

​Pressure drop
The difference in pressure between two areas of a pump, or between the inside and outside of a container.

​Efficiency
The measured power out of a piece of equipment divided by the power produced by the piece of equipment. Shown as a percentage.

​BEP
Best Efficiency Point. The kinetic energy that a pump produces is never converted with 100% efficiency to pressure energy. There are always losses due to friction in the seals / bearings, friction of the pumped fluid over the impeller, etc. The BEP is thevolumetric flow rate of the pump for which the pump was designed to convert the most kinetic energy into pressure energy.

​NPSHA
The net positive suction head available that can be used to prevent cavitation within the pump. It is defined as static head plus surface pressure head minus the vapour pressure of the process fluid minus the friction loss due to the piping, valves and fittings.

​NPSHR
Net positive suction head required to keep a pump from cavitating. A characteristic of the pump. Calculated by the manufacturer with cold water.

Cavitate
Formation of cavities (bubbles) in fluid flow applications in areas of low pressure, causing a collapse in the high pressure area of the pump and loss of capacity, excessive noise and possibly damage.

​Specific gravity (SG)
The ratio of the density of a substance compared to the density of a reference (usually water at 4 °C).

BHP
Brake horsepower. The measure of an engine’s horsepower before the loss in power caused by any load (gearbox, etc.). Measured by attaching a “Prony brake” to the engine’s shaft.

​Flooded suction
If the pump is below the liquid source, and the suction is fed by gravity. This is a preferred method for centrifugal pumps.