In commercial paint spraying, piston pumps have become the industry standard. This is due to their high output, compact size, and excellent reliability.
An electric piston pump uses a lightweight, compact motor as a power source. The motor turns at a relatively high RPM, which must be reduced before power can be transferred to the piston rod. This is accomplished through a built in gear reduction system. Once the speed is reduced, the rotary motion is converted to linear motion by an off-center bearing or crankshaft, and then coupled to the piston. The piston system in all Lemmer pumps is double acting, which means it pumps when going up AND down for a more constant pressure delivery.
Paint is typically drawn into the pump by vacuum and is pressurized up to several thousand PSI before it enters the spray hose. At the spray gun, this high pressure is forced through a small orifice, making the paint accelerate to a high speed and atomize when it hits the surrounding air. Since paint is delivered to the point of application by pressure only, airless spray offers high application rates with minimal overspray.