Abstract: This cleaning system is designed to automated and minimize or eliminate the excessive amount of manpower associated with other suction processes. It is a combination of paint recovery, and flushing methods in a automated manner. It is designed to minimize the paint lost as a result of color changing of circulation systems, as well as minimize the associated time and solvents used to in the cleaning process. This is accomplished by inserting a first pig into the circ system at the end of a desired painting cycle to push out the paint and propelling the first pig through the system using a solvent. The location of the first pig is then sensed and the first pig collected from the system. A second pig is injected into the system to separate the solvent from a new cycle of paint.

Abstract: A paint circulation system for supplying paint to a plurality of distributors utilizing a circulating pump to circulate paint to the distributors and an injection pump operated by a closely controlled electric motor for injecting paint into the circulation network from a paint supply reservoir to maintain a predetermined pressure within the circulation network. A "leakage" passage having a predetermined restriction permits paint to leave the circulation network when the valved paint distributors are closed, and the use of an automatic timing valve within the leakage bypass permits flow rates within the circulation network to be varied. The components permit paint viscosity and volumes to be determined, settling of the paint particles within the circulation network and degradation of the circulating paint is minimized, and circulating motor wear may be determined.