AUTOMATIC METERING UNIT Russian patent published in 2013 - IPC A62C27/00 

FIELD: fire-prevention facilities.

SUBSTANCE: invention relates to the field of fire-fighting equipment, in particular to foam extinguishing systems, and enables to maintain automatically the given concentration of the foam generating agent in aqueous solution, regardless of its flow rate. The automatic metering unit for special systems of foam extinguishing of fire-fighting ships and boats comprises a pipe of pressure piping of the system, connected by the curved tubes to the metering unit housing. In the metering unit a float with a rod is mounted, as well as a cylinder with calibrated windows and a piston rigidly connected to the float. And the horizontal ends of the tubes are located along the pipe axis and directed to the end of the lower tube in the opposite direction, and the end of the upper tube is in the direction of liquid flow. In the inner space of the metering unit housing the liquid flow parallel and proportional to the main flow is created, by which hydrodynamic force the float and the piston connected to it hold a certain position, changing the passage areas of calibrated windows.

EFFECT: increased accuracy and reliability of automatic maintenance of necessary concentration of foam generating agent in aqueous solution at any uncontrolled change in flow rate of the solution by the consumers is achieved.

1 cl, 2 dwg