The Qualiflow HDV is an innovative stainless steel float box, integrating the patented Variflow HDV float valve. This system regulates the water supply to pasture troughs with great precision, simplicity, and robustness. The Variflow HDV ensures an adjustable flow rate of 30, 50, or 90 liters/minute at 3 bars, also at low pressure < 1 bar, via an end-stop system. The water level is adjusted without tools, by positioning the float on a notched arm with a movable axis. Manual shut-off of the water supply is done via an upper lever, accessible from the top, without disassembling the protective stainless steel cover, making maintenance and control accessible, safe, and fast. The mechanism remains out of reach of animals. The box can be fixed to all standard troughs on the market, thanks to adjustable brackets (trough thickness from 40 to 80 mm). The entire device is robust, compact, and fully disassemblable without tools, for optimized water management in livestock farming.