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 the ink source, an ink outlet in fluid communication with the 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 the lower pressure differential to the higher pressure differential across the flexible wall causes the flexible wall to actuate and flex the flexible arm without causing the lever to pivot.