Abstract: In a plant for automatic spray application of paint through a spray nozzle (12), two parallel lines (9,10) each lead from an associated arrangement (1,2) for supplying paint to the spray nozzle. After paint has been fed through one of the lines to the spray nozzle followed by closing of a valve means (15,16) associated therewith for changing the arrangement (1, 2) supplying paint, a device (24) is adapted to feed such a volume of fluid into this line upstream of the valve means, with respect to the paint feeding direction, in the reverse direction so that the paint present in the line is pushed back into the arrangement without the fluid reaching it.

Abstract: A paint dosage device is particularly adapted to be mounted in close proximity to a spray gun (P) in a program controlled spray painting installation for dosed paint supply to the spray gun. The device includes at least two dosage cylinders (SA,SB), each having a regulating piston (PA,PB) connected to a piston departure position and displacement velocity regulator (RA,MA:RB,MB) for setting the paint filling amount of the associated cylinder by controlled adjustment of the departure position of the regulating piston in the cylinder, and for setting the dosage rate of the cylinder when supplying paint to the spray gun, by program controlling the displacement velocity of the regulating piston in the cylinder. A valve assembly (V1,V2,V3,V4) is arranged for connecting the cylinders (SA,SB) alternately to the spray gun (P) and putting the cylinder disconnected from the gun in connection with means for cleansing and paint filling apparatus.