Ball check valve for bulk ink supply system

The present invention relates generally to the field of inkjet printing, and more particularly, to bulk ink supplies for inkjet printing systems. A ball check valve for use in a bulk ink supply system of an inkjet printing system, for disposal in an ink flow path between an ink reservoir and a printhead, so as to control back pressure at the printhead thereby reducing the occurrence of de-priming of the printhead, including a valve body defining a chamber with an inlet and an outlet; a ball disposed in the chamber, the ball having a diameter; a ball retainer disposed in the inlet, the ball retainer having an aperture with a diameter which is less than the diameter of the ball, wherein backflow of ink in the chamber causes the ball to seat against the ball retainer, placing the ball check valve in a closed position such that ink flow through the aperture is restricted.