Abstract: A regulator adapted to regulate the throughput of an ink between an ink source and a print head includes: (a) a pressurized chamber including an ink inlet in fluid communication with and ink source, an ink outlet in fluid communication with a print head, and at least one flexible wall; and (b) a lever including a flexible arm extending along a portion of the flexible wall and an opposing arm operatively coupled to a seal biased to close the ink inlet when the lever is in a first position and to open the ink inlet to allow fluid communication between the ink inlet and the pressurized chamber when the lever is pivoted to a second position; where a lower pressure differential across the flexible wall causes the flexible wall to actuate the flexible arm, pivoting the lever to the first position (inlet closed), where a higher pressure differential across the flexible wall causes the flexible wall to actuate the flexible arm to pivot the lever to the second position (inlet open), and where a pressure change from th