Abstract: A device for filtering oil circulating in a hydraulic circuit for operating hydraulic actuators has at least one inlet port for the oil entering the device, at least one outlet port for oil flowing out of the device, a main filter to filter the oil flowing from the inlet port to the outlet port, at least one auxiliary or discharge port and one or more by-pass ports to place the device in fluid communication with an oil accumulator. A main valve assembly is arranged between the main filter and the auxiliary or discharge port. The device extends along an axis and has by-pass valves arranged between the inlet port and the by-pass ports. The by-pass valves are radially arranged about the main valve assembly.