Firefighting foam-mixing system

A firefighting foam-mixing system, comprising:

• a water line for providing a water flow,
• a storage tank having an inlet and an outlet, the storage tank comprising an internally arranged membrane adapted for holding a foaming agent and connected to the outlet,
• a first conduit having a first end connected to the inlet of the storage tank, and
• a second conduit having a first end connected to the outlet of the storage tank and a second end connected to the water line at a first position,
• wherein:
• the firefighting foam-mixing system further comprises a water diverter arrangement connected to the water line at a second position and to a second end of the first conduit, the second position being upstream of the first position in relation to the water flow through the water line,
• the water diverter arrangement is configured to, independent of a current flow of water at the second position, divert a predetermined proportion of the water flowing through the water line at the second position, to the first conduit for pressurizing an outside surface of the membrane.