A firefighting pump is a special pump that provides adequate pressurised water for extinguishing fires. The pump may be connected to underground tanks and reservoirs or water pipes. Fire pumps are powered by diesel or electric motors. The fire pump starts when the water system goes below certain threshold, which happens when a fire fighting connection is opened. Fire pumps can be categorised into two categories: centrifugal and positive displacement.
The firefighting equipment used before the invention of the fire pump consisted mostly of buckets and lines for passing the buckets. Some of the early civilisations invented different forms of handheld pumps to put out fires.
In the second century B.C., the Greek inventor Ctesibius introduced a handheld wooden pump to the Greeks. His invention was probably “borrowed” from the Egyptians. Centuries before his invention, the Egyptians were putting out fires using hand-operated pumps.
The Romans introduced the first fire pump to Britain between 27 B.C and 14 A.D. The use of this equipment stopped when the Romans left the British Isles. After the great fire of London in 1666, the British devised fire fighting pumps that drew water from ponds and rivers through hoses.
The invention of the steam pump in the 19th century facilitated firefighting to a great extent. Steam pumps were faster than hand-to-hand water brigades were. In the 20th century, the motorised pump was invented. The first fire engine used a single motor for the dual functions of running the vehicle and pumping water to fight fires.
As cities grew during the industrial revolution, the focus on mechanical devices set the stage for the development of extraordinary firefighting equipment throughout the world.
This type of fire pump traps a fixed amount of water in it then forces it out through a discharge pipe. This type of pump can be subdivided further into two categories: reciprocating pumps and rotary pumps. Examples of reciprocating pumps include piston and diaphragm pumps. Screw and gear pumps can be categorised as rotary pumps. Of the two types of positive displacement pumps, rotary pumps are the most common fire fighting pumps. They are used as primary pumps for filling hoses, lines and main pumps.
This type of pump is normally used as the main pump in firefighting systems. Centrifugal pumps use revolving devices called impellers that accelerate water in a radial pattern from the center of the pump housing. The acceleration creates velocity inside the pump. This velocity, coupled with the resistance of the pump housing and discharge line leads to the buildup of pressure, which forces water out of the pump. In addition, vacuum created at the opening of the impeller continuously draws in more water.
The main difference between the two types of fire fighting pumps is that displacement pumps can pump air whereas centrifugal pumps cannot. This is the reason why displacement pumps are used as primer pumps because they are suitable for filling empty water lines. Centrifugal pumps are used as main fire pumps because they have higher flow rates and efficiency.
For more information about fire fighting pumps, click here.