Method for cleaning spray drying systems, comprising the following steps (i) providing a spray drying reactor; (ii) providing of at least two pipelines (L1, L2) for feeding aqueous starting materials, containing (ii-a) a first multi-way valve V1 for metering in a cleaning liquid, (ii-b) a second shut-off valve V2 located between the first shut-off valve V1 and the reactor for metering in compressed air, and (ii-c) valves V3 arranged according to the number of nozzle lances for introducing the product into the reactor (ii-d) a three-way valve V4 for draining the compressed air system (ii-e) valves V5 arranged according to the number of nozzle lances for blowing out the nozzle lances with compressed air (ii-f) a shut-off valve V6 after the three-way valve to shut off the compressed air connection (iii) providing a nozzle table per pipeline with at least one nozzle and preferably 5 to 10 nozzles (D1... D10), (iv) providing of a cleaning collecting tray R E, (v) providing a feed pump per pipeline, optionally provided with a pressure relief valve, and whereby the pipes are operated alternately, are connected to the head of the reactor and end in the nozzles (D1... D10), characterized in that each change of the pipelines, the shut-off valves V1-V6 are opened and closed in four steps in the following directions: Step Valve V1 Valve V2 Valve V3 Valve V4 Valve V5 Valve V6 R C R D R C R D R A R B R C R D R E R A R D R C R D (a) ZU zu auf auf zu zu auf auf zu auf auf auf auf (b) zu zu zu zu zu zu zu zu zu zu zu zu zu (c) zu/auf zu/auf zu/auf zu/auf auf/zu auf/zu auf zu auf zu/auf zu/auf zu/auf zu/auf (d) auf auf auf auf auf auf auf auf zu auf auf auf auf wherein: R A direction spray drying reactor; R B direction starting materials; R C direction cleaning liquid; R D direction compressed air and R E direction cleaning collecting tray. (i) providing a spray drying reactor; (ii) providing of at least two pipelines (L1, L2) for feeding aqueous starting materials, containing (ii-a) a first multi-way valve V1 for metering in a cleaning liquid, (ii-b) a second shut-off valve V2 located between the first shut-off valve V1 and the reactor for metering in compressed air, and (ii-c) valves V3 arranged according to the number of nozzle lances for introducing the product into the reactor (ii-d) a three-way valve V4 for draining the compressed air system (ii-e) valves V5 arranged according to the number of nozzle lances for blowing out the nozzle lances with compressed air (ii-f) a shut-off valve V6 after the three-way valve to shut off the compressed air connection (ii-a) a first multi-way valve V1 for metering in a cleaning liquid, (ii-b) a second shut-off valve V2 located between the first shut-off valve V1 and the reactor for metering in compressed air, and (ii-c) valves V3 arranged according to the number of nozzle lances for introducing the product into the reactor (ii-d) a three-way valve V4 for draining the compressed air system (ii-e) valves V5 arranged according to the number of nozzle lances for blowing out the nozzle lances with compressed air (ii-f) a shut-off valve V6 after the three-way valve to shut off the compressed air connection (iii) providing a nozzle table per pipeline with at least one nozzle and preferably 5 to 10 nozzles (D1... D10), (iv) providing of a cleaning collecting tray R E, (v) providing a feed pump per pipeline, optionally provided with a pressure relief valve, and whereby the pipes are operated alternately, are connected to the head of the reactor and end in the nozzles (D1... D10), characterized in that each change of the pipelines, the shut-off valves V1-V6 are opened and closed in four steps in the following directions: Step Valve V1 Valve V2 Valve V3 Valve V4 Valve V5 Valve V6 R C R D R C R D R A R B R C R D R E R A R D R C R D (a) ZU zu auf auf zu zu auf auf zu auf auf auf auf (b) zu zu zu zu zu zu zu zu zu zu zu zu zu (c) zu/auf zu/auf zu/auf zu/auf auf/zu auf/zu auf zu auf zu/auf zu/auf zu/auf zu/auf (d) auf auf auf auf auf auf auf auf zu auf auf auf auf wherein: R A direction spray drying reactor; R B direction starting materials; R C direction cleaning liquid; R D direction compressed air and R E direction cleaning collecting tray.