Hemodialysis machine with vent valve

摘要

A hemodialysis machine includes a chemical treatment system having a source (90) of chemical, and a proportioning pump (66) which pumps a dialysate concentrate in a dialysis mode, and pumps the chemical in a chemical treatment mode used for cleaning the machine. A vent valve (98) is provided for decoupling the chemical source (90) from the pump (66) by coupling an air source to the pump (66) when the machine is not in the chemical treatment mode. This ensures that cleaning chemicals are not inadvertently pumped during the dialysis mode.