Dosing device

Device for dosing liquid effective substances in flowing water comprising a housing arranged to conduct water through a flow path therein, said housing being arranged for connection to a water line, a drive mechanism located in the water flow path in said housing and arranged to be driven by the water flowing therethrough, a dosing pump driven by said drive mechanism, a replaceable tank containing the liquid effective substance, an injection valve arranged to deliver the liquid effective substance to the water flowing through said housing, said dosing pump having a suction side connected to the interior of said tank and a pressure side connected to said injection valve, wherein the improvement comprises that said tank and said dosing pump form a disposable unit removable mountable on said housing and connectable with said driving mechanism said dosing pump comprises a piston pump including a cylinder, a piston guided in said cylinder, a tappet connected to said piston, and spring means for biasing said tappet into contact with said drive mechanism, said tank including a chamber separate from the interior of said tank and being in communication with the interior of said tank, said pump cylinder including said piston being located within said tank chamber, a valve body located at the opposite end of said cylinder from said tappet and providing a closure from said cylinder to said chamber, said chamber having an opening therethrough at the opposite end thereof from said valve body and opening to the exterior of said tank, said tappet extending from said opening to the exterior of said tank, and means forming a sealed closure between said through opening and said tappet.