Pressure washer
（重定向自High pressure water cleaning）
A pressure washer or power washer is a high-pressure mechanical sprayer used to remove loose paint, mold, grime, dust, mud, and dirt from surfaces and objects such as buildings, vehicles and concrete surfaces. The volume of a pressure washer is expressed in gallons or litres per minute, often designed into the pump and not variable. The pressure, expressed in pounds per square inch, pascals, or bar (deprecated but in common usage), is designed into the pump but can be varied by adjusting the unloader valve. Machines that produce pressures from 750 to 30,000 psi (5 to 200 MPa) or more are available.