A hemodialysis system is disclosed. The hemodialysis system includes a dialyzer, a saline container including saline, and a disposable set comprising a blood pumping tube fluidly connected to a first end of the dialyzer, an arterial line fluidly connected to a first end of the blood pumping tube, a venous line fluidly connected to a second end of the dialyzer, a saline line fluidly connected to the blood pumping tube and the saline container, and a dialyzer line fluidly connected to a second end of the blood pumping tube and a second end of the dialyzer. The hemodialysis system also includes a dialysis instrument comprising an arterial line clamp, a venous line clamp, and a saline valve. The saline rinses blood out of the arterial line when the venous line clamp is closed, the arterial line clamp is opened, and the saline value is opened.