Basic Operating Principles Water pumps on fire trucks are usually based on the centrifugal principle. The basic working principle of centrifugal pumps is as follows:Centrifugal Pumps: These pumps move water by centrifugal force created by a rotating impeller. Water enters the centre of the impeller and is pushed towards the periphery of the impeller by rotating rapidly. This movement ensures that the water is directed to the outlet point with high pressure. Centrifugal pumps are widely used in fire trucks because they can provide high flow and pressure. Types of Water Pumps Water pumps used in fire trucks can be found in different types to meet various needs. The main pump types are as follows:Single Stage Centrifugal Pumps: These pumps pressurise water using a single impeller. They are generally used in simple firefighting operations and are suitable for situations requiring lower pressure.Multistage Centrifugal Pumps: These pumps pressurise water progressively using multiple impellers. They are used in firefighting operations where high pressure is required, especially in high-rise buildings and large areas.Gear Pumps: These pumps, which are in the category of positive displacement pumps, move water with the rotation of gears. They are generally preferred for high viscosity liquids, but are rarely used in fire trucks.