The VHP70 valve is an hydraulic device that regulates/limits the pressure. When the high pressure water spray gun connected to the valves outlet (OUT) is opened, the high pressure water sprays through the nozzle. The pressure created, if the nozzle size is fixed, depends on the flow rate that crosses it (it rises as the flow rate increases). The VHP70 valve regulates this pressure by opening the by-pass hole, which lets out the excess water so that the pump can be kept at the required pressure. This
value must not exceed the Rated Pressure for which the valve is designed. A feasible excess flow rate (the one that will cause the
pressure to rise beyond the set value if flow through the
nozzle) is discharged from the valve through the by-pass hole.