The invention relates to a dosing mechanism for a fluid, comprising an inlet, an outlet, a dosing pipe and two valve groups with an inlet valve and an outlet valve each, wherein the inlet is connected to both inlet valves and the outlet is connected to both outlet valves, wherein the inlet valve of one group is arranged to connect the inlet to a first end of the dosing pipe while the outlet valve of the same group is arranged to connect the outlet to a second end of the dosing pipe, wherein the inlet valve of the other group is arranged to connect the inlet to the second end of the dosing pipe while the outlet valve of the same group is arranged to connect the outlet to the first end of the dosing pipe, wherein control means are arranged to open only the valves of one group at a time thereby allowing the fluid to flow from the inlet through the dosing pipe to the outlet, wherein a dosing object is arranged in the dosing pipe in a manner to be translated from one end towards the other by the fluid, wherein a dose to be delivered from the output is determinable by a position of the dosing object in the dosing pipe.
