A dialysis machine that includes a valve member having a deformable area configured to deform outwardly away when pressurized fluid is introduced into the valve member. The valve member is configured so that, when a dialysis fluid cassette is disposed in a cassette compartment of the dialysis machine and pressurized fluid is introduced into the valve member, the deformable area obstructs a fluid channel of the dialysis fluid cassette to control dialysis fluid flow therethrough.