Arrangement to supply a print head unit having at least one print head with ink in an ink printing apparatus

An arrangement to supply ink to a print head unit having a print head, an input, and an output in an ink printing apparatus, comprising:

• a back-pressure tank having ink and that is connected with said input of the print head unit via a supply line;
• a degassing unit for ink and having an input and an output;
• a first selector valve connected to said degassing unit input, said first selector valve in a first position establishing a connection of the degassing unit with the output of the print head unit;
• a second selector valve connected to said degassing unit output, said second selector valve in a first position establishing a connection of the degassing unit with the back-pressure tank;
• said first selector valve also having a second position for feeding ink from a reservoir to said input of said degassing unit and then to said back-pressure tank through said second selector valve in said first position;
• and
• said second selector valve also having a second position such that ink from said print head unit is fed through said first selector valve in said first position to said input of said degassing unit and then to said reservoir through said second selector valve in said second position.