A disposable pumping cassette in one embodiment includes a pump chamber; and a valve chamber in communication with the pump chamber, the valve chamber including an inlet and first and second outlets. A disposable pumping cassette in another embodiment includes a first valve chamber including an inlet and first and second outlets; and a second valve chamber including an inlet and an outlet, the second valve chamber openable to allow dialysis fluid to flow through one of the first and second outlets of the first valve chamber, through the outlet of the second valve chamber. A disposable pumping cassette in a further embodiment includes a valve chamber including a fluid inlet and first and second fluid outlets; and a flexible sheet openable to open and close only one of the first and second outlets.