Pressure washers force the water through a hose with the help of a motor and blast the water on the items to remove the dirt off their surfaces. They produce ten times greater pressure than a garden hose and also use just one-fourths of water used by a normal hose. So, they are efficient tools for dislodging the dirt off many of the outdoor items. You can also use detergent with the water so that dirt is removed even more efficiently.

Pressure washer has following parts which are assembled as a unit.

• A powerful motor that pumps the water through the hose at high pressure.
• The hose attached to the water supply
• The spray lance assembly with an adjustable nozzle.
• The trigger to open the valve.
• Some pressure washers have thermal switch to prevent overheating.

The underlying principle of pressure washers is based on the cleaning power of pressurized water which is blasted out through a nozzle. The various components of the pressure washer produce the powerful jet of water which removes the dirt off the surface.

Here is the mechanism behind an electric pressure washer:

The hose is connected to the water supply before the pressure washer is switched on. The electric motor runs the pump that increases the pressure of water to a level of 120 or 130bar. The pump has a pressure switch which automatically turns off the motor once the water is pressurized to the required level. The pressurized water stays in the pump ready for use.

Then, the trigger in the pressure washer turns on a valve and this releases the water through the pressure hose and the water finally reaches the spray lance assembly.

The lance has a nozzle whose holes can be adjusted by the user to increase or decrease the pressure of water that exits from the holes.

While the trigger is pressed, the motor automatically runs and the pump driven by the motor pressurizes the water that comes from the domestic water supply.

In few models, the electric motor continues to run even when the trigger is not pressed. However, these pressure washers come with a thermal switch which automatically turns off the motor when the motor becomes too hot.

On most occasions, pressure washers do the cleaning tasks more efficiently than a garden hose. In fact, they are used for some specific tasks that need to be done only by pressure washers such as removing of rust, old paint and creasy materials off the surfaces.

Here is a list of uses of pressure washers:

• Automobile vehicles like motor cycles, cars, boats and bicycles can be cleaned.
• The algae, fungus or moss can be removed from walls, roofs etc.
• Domestic user can clean the driveways, fences, walls and patios.
• Farm surroundings, stable and poultry can be cleaned thoroughly to maintain better hygiene.