Abstract: The invention relates to an automatic device for mixing fluids, particularly paints or varnishes, that are to be sent on to one or more mixing containers (9), said device comprising a plurality of circuits (1), independent of one another, and in particular a circuit (1) for each fluid being dosed, each circuit (1) comprising a storage tank (2) for storage of the fluid, a pump (4) for taking in the fluid from said storage tank (2) and for delivery thereof into said mixing container (9), valves, pipes, and an automatic-control device, also comprised in which are a plurality of precision circuits (1?), each one of which associated in parallel to each of said circuits (1), each of said precision circuits (1?) sharing with the associated circuit (1) the same storage tank (2) and the same automatic-control device and further comprising a precision pump (4?) for taking in the fluid from said storage tank (2) and for delivery thereof into said mixing container (9), as well as valves and pipes of their own.

Abstract: A metering valve wherein an outer casing defines a first and second chamber communicating with each other via a hole and respectively communicating externally of the casing via a fluid inlet conduit and a fluid recirculating conduit. The first chamber also communicates externally via a supply conduit, and houses a shutter movable axially inside the chamber between a first position wherein a first portion of the shutter closes the aforementioned hole, and a second position wherein a second portion of the shutter closes the supply conduit. For any intermediate position between the first and second positions, the total area of the gaps between the supply conduit and the second portion and between the hole and the first portion is notably constant, so that, for any position of the shutter, the total section of the fluid passage of the metering valve is constant.