Flush valve and pump station comprising such a flush valve

A flush valve configured to be connected to a pump, which is located in a reservoir containing liquid, the flush valve comprising:

• an inlet configured to be in fluid communication with a volute of said pump,
• an outlet configured to open into said reservoir, and
• a valve arrangement comprising (i) a first chamber, (ii) a second chamber that is partly delimited by a diaphragm, (iii) a conduit extending between and connecting the first chamber and the second chamber, (iv) a third chamber that connects the inlet and the outlet of the flush valve and that is partly delimited by said diaphragm, the third chamber comprising a valve member configured to control a fluid flow from the inlet to the outlet based on the position of said diaphragm, and (v) a control mechanism arranged in said conduit,
• wherein said control mechanism comprises a stepper and a plunger, the plunger being displaceable in use back and forth between an inactive position and an active position, the plunger being biased towards said inactive position and being displaced towards said active position by a second pressure [P2] in the second chamber when said second pressure [P2] in the second chamber is greater than a threshold value [PT], the plunger being configured to engage the stepper when the plunger is displaced towards the active position,
• wherein the stepper, each time the plunger engages the stepper, changes position once in a repeated set of positions according to a step-by-step routine, and
• wherein the stepper, in at least one position of said set of positions, enables fluid communication between the first chamber and the second chamber via said conduit.