Printing apparatus on a print support comprising: - A print head to print on said print support a print material; - A feed device to feed said print material to said print head, and - A recirculating unit to generate a recirculation of said print material through said print head, said recirculating unit in its turn comprising: a. A first container of said print material placed upstream of said print head; b. A second container of said print material, placed downstream of said print head; c. A first recirculating sub-unit to generate a first flow of said print material from said first container to said print head and said second container; d. A second recirculating sub-unit to transfer said print material from said second container to said first container, wherein said first container and second container are both maintained under two distinct negative pressures and in which the feed device comprises an accumulation tank, a pumping device and an ink refilling pipe for feeding refilling ink to a first container of the recirculating unit, which ink refilling pipe connects the output of pumping device with the said first container, and a pumping device control unit is provided; characterized in that the pumping device control unit is configured to drive the pumping device in a pulsed manner, for feeding in an alternate manner predetermined amounts of ink from the accumulation tank to the first container. - A print head to print on said print support a print material; - A feed device to feed said print material to said print head, and - A recirculating unit to generate a recirculation of said print material through said print head, said recirculating unit in its turn comprising: a. A first container of said print material placed upstream of said print head; b. A second container of said print material, placed downstream of said print head; c. A first recirculating sub-unit to generate a first flow of said print material from said first container to said print head and said second container; d. A second recirculating sub-unit to transfer said print material from said second container to said first container, a. A first container of said print material placed upstream of said print head; b. A second container of said print material, placed downstream of said print head; c. A first recirculating sub-unit to generate a first flow of said print material from said first container to said print head and said second container; d. A second recirculating sub-unit to transfer said print material from said second container to said first container, wherein said first container and second container are both maintained under two distinct negative pressures and in which the feed device comprises an accumulation tank, a pumping device and an ink refilling pipe for feeding refilling ink to a first container of the recirculating unit, which ink refilling pipe connects the output of pumping device with the said first container, and a pumping device control unit is provided; characterized in that the pumping device control unit is configured to drive the pumping device in a pulsed manner, for feeding in an alternate manner predetermined amounts of ink from the accumulation tank to the first container.