Airless spraying is the use of piston pumps, diaphragm pumps and other forms of booster pumps to pressurize the liquid paint, and then through the high-pressure hose to the airless spray gun, and finally in the airless nozzle at the release of the hydraulic pressure, instantaneous atomization, sprayed to the surface of the painted object, the formation of coating layer. Since the paint does not contain air, it is called No air spraying , or airless spraying for short.