US measure for rate of flow. Metric measures in litres per minute. The Orifice is the opening in the spray tip. It is important to select the right orifice for the coating to be sprayed. Heavier coatings require larger openings to flow through.
Thin coatings require smaller orifice sizes.
Heavy coatings will clog small orifices, thin coatings will not atomize properly through large openings. Packings Packings prevent fluid leakage. They are located around the piston in a piston pump system and also around the gun needle. Packings can be mounted on the rod or in the cylinder. Piston Pump A piston pump is composed of a piston rod and a cylinder.