An inlet seal, an outlet seal, and a piston are connected to a shaft. The inlet seal seals an ink inlet of an ink reservoir. The outlet seal seals an ink outlet of the ink reservoir. Also, the piston is within a cylinder. The inlet seal, the outlet seal, and the piston all move with the shaft. A biasing member contacts the piston to bias the piston in a first direction. Pressurized air simultaneously provided to the cylinder and to the ink reservoir biases the piston in a second direction, opposite the first direction, and pressurizes ink within the ink reservoir. Moving the shaft in the first direction does not seal the ink inlet but does seal the ink outlet. Moving the shaft in the second direction seals the ink inlet but does not seal the ink outlet, thus allowing the pressurized ink out from the ink reservoir.