Diesel Water Pumps
Diesel powered water pumps are most frequently used in areas where there is no electrical
current available. Diesel water pumps are therefore typically used by farmers, local authorities,
builders, and for maritime use. They are also used as fire pumps.
Diesel water pumps are typically much larger than utility water pumps, measuring on
average a 20 inch cube (50 cm cube). They are freestanding and typically feature a carry handle because these pumps
are usually moved around from one place to another as needed, instead of being permanently installed. Diesel water
pumps are relatively expensive compared to electrically driven water pumps, but are more powerful, offering 3-7
horsepower.
Diesel Water Pumps: Centrifugal Versus Diaphragm
Diesel water pumps have one of two main modes of action: centrifugal or diaphragm. It is
important to determine which one is desired for the application at hand, because the two modes of action result in
very different pump properties. The centrifugal diesel water pump works via an impeller, which is a rotating blade
which pushes the water against the walls of the cylinder to give the water high pressure. The diaphragm water pump
works by pressurizing hydraulic oil using a plunger, which flexes a diaphragm inside the pump that drives the
liquid.
Centrifugal diesel water pumps give the strongest pressure and is therefore best when large
amounts of water need to be moved quickly, for example if jetting is needed. However, the centrifugal water pump
can lose its prime, meaning that instead of a liquid-only environment, air can eventually seep into the pump,
decreasing performance. Losing the prime is less likely if the inlet material is strictly water, but if dirt or
slurry is also present, air can more easily be introduced. The diaphragm water pump is less prone to this problem,
but it works more slowly. A diaphragm diesel water pump is therefore ideal for removing slow seepage of water,
especially in an environment where there is a high proportion of sludge or other solids in the water.
Specialized Diesel Water Pumps: Fire Pumps
Fire pumps are used to provide sufficient water to sprinklers in buildings, because in the event
of a fire, the municipal water supply may not be enough to maintain enough water pressure at all sprinkler heads. A
fire pump is therefore an example of very specialized water pumps, and is most commonly diesel or electric powered.
The advantage of using diesel water pumps is that it will still work even if the fire has affected the electrical
power to the site. On large sites, two fire pumps are often used; sometimes one diesel and one electrical, to
ensure at least one will be operational even if the other fails.
Fire pumps should be tested regularly to ensure they will start and run (these are dry tests).
Less frequently, wet (flow) tests should be done annually to ensure that the flow does indeed meet the
specifications. For convenience, flow tests are done through a test head, rather than to all the sprinklers in the
building. If the flow of a fire pump does not meet the specifications, then it is an indication that something is
falling out of repair and needs to be diagnosed and fixed.
Fire pumps have regulations governing their specifications; these are slightly different in
each country. Therefore, when purchasing a diesel fire pump, it is important to select one whose specifications
fit the regulations of the country in which it is to be used.
Diesel Water Pumps Are Multi Functional
Diesel water pumps have the advantage of being functional even on sites where there is no
electricity. This feature makes the diesel water pump ideal for agricultural, construction, and maritime use. In
the urban setting, the diesel powered fire pump is a very specialized water pump, unlike mini water pump, which delivers water at sufficient pressure to sprinkler heads
in the event of a fire. Diesel water pumps are therefore very versatile.
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