Patent attributes
A downhole tool includes a housing and a mandrel glidingly arranged within the housing, wherein the mandrel is formed as a piston. The flange is acting on a spring arranged around the mandrel. In a first position of the mandrel, a fluid flow can run 100% through the tool via a first nozzle at a first end of the housing, the inside of the mandrel and a second nozzle at a second end of the housing. At a predetermined flow rate and with the help of a passage arranged in the housing wall and connecting the first side of the tool with the space or ring room on the non-spring side of the mandrel and a side port in the mandrel on its spring side, the mandrel will be moved towards the second nozzle due to sufficient force acting on a flange of the mandrel thus overcoming the spring resistance.