Noise-reducing dialysis systems and methods of reducing noise in dialysis systems

A dialysis system comprising:

• first and second pneumatic valves;
• a first pneumatic pump head in fluid communication with the first pneumatic valve;
• a second pneumatic pump head in fluid communication with the second pneumatic valve;
• a first pneumatic line communicating directly with an inlet and an outlet of the first pneumatic pump head;
• a second pneumatic line communicating directly with an inlet and an outlet of the second pneumatic pump head;
• a first flow restrictor placed in the first pneumatic line;
• and
• a second flow restrictor placed in the second pneumatic line,
• wherein the first and second valves are configured (i) in a noise-reducing state to cause at least one of (a) air to re-circulate through the first pneumatic line and the first flow restrictor and (b) air to re-circulate through the second pneumatic line and the second flow restrictor, and (ii) in a pressure-supplying state to cause pressure to be supplied to a component of the dialysis system via at least one of the first and second pneumatic valves.