Adding system for fire-extinguishing units

An adding system for fire-extinguishing units for producing a mixture of extinguishing agent and extinguishing agent additive (premix) by adding an extinguishing agent additive to an extinguishing agent, comprising

• a motor able to be driven by a flow of extinguishing agent with an input for supplying the extinguishing agent to the motor, an output for discharging the extinguishing agent from the motor, and an output shaft able to be driven by the motor,
• an adding pump for conveying the extinguishing agent additive which has an input shaft coupled to the output shaft of the motor, an inlet for providing the extinguishing agent additive, and an outlet for discharging the extinguishing agent additive,
• an adding line having a first motor-side end and a second outlet-side end, wherein the motor-side end is fluidly connected to the output of the motor,
• an extinguishing agent additive line having a first pump-side end and a second adding line-side end, wherein the pump-side end is fluidly connected to the outlet of the adding pump and the adding line-side end is fluidly connected to the adding line at an admixture point, and
• wherein the inlet of the adding pump is arranged at the adding pump such that the extinguishing agent additive can flow into the adding pump substantially parallel to the direction of movement of at least one of the pistons of the adding pump.