Pressure washing

The pressure, expressed in pounds per square inch, pascals, or bar, is designed into the pump but can be varied by adjusting the unloader valve or using specialized nozzle tips.

An industrial pressure washing surface cleaner is a tool consisting of two to four high-pressure jets on a rotating bar that swivels when water is flowing.

A pressure washer is used to clean residential surfaces such as gutters, roofs, decks, paved areas, siding, cladding, and windows.

[4] Hot water pressure washers are best for washing flatwork (concrete driveways, walkways, etc) that can have grease or oil residue.

When the unit is moved over the surface the rotating jets clean a swathe a little smaller than the circular cover, which confines splashback and reduces noise.

[7] High-pressure water jetting, also called hydrojetting, is a variation in which the pressure can be significantly higher (up to 1,400 bars (20,000 psi)) than consumer models, and is sufficiently hazardous that special precautions are necessary for acceptable safety.

High-pressure water jetting also has applications in cutting a wide range of materials with very low heat input or dust production, and can be effective underwater.

It is used for cleaning tanks, pipes, sieves, filters and heat exchangers, for removal of coatings, corrosion products, scale, old paint, burned materials, biological fouling, and many insoluble substances, with little or no damage to the substrate when the appropriate pressure is used.