A flushing apparatus for use with an iv infusion set and an iv infusion set having an automatic flushing function

An IV bag (20) comprising a collapsible infusion liquid chamber (21), said collapsible infusion liquid chamber (21) having an upper end and a lower end, said IV bag (20) comprising a container (3) defining a rigid and/or non-collapsible flushing liquid chamber (2) for containing a flushing liquid and containing said flushing liquid, said flushing liquid chamber (2) having an upper end and a lower end, wherein:

• said flushing liquid chamber (2) being a closed chamber, except for at least one flushing port (7) at or near the lower end of said flushing liquid chamber (2) and at least one venting port (17) for allowing air from said bag (20) to enter said flushing liquid chamber (2), said venting port (17) being fluidically connected to bag (20) at a vent height (VH), said vent height (VH) being above the flushing port (7);
• said at least one flushing port (7) being fluidically connected to said collapsible infusion liquid chamber (21) at or near said lower end of said collapsible infusion liquid chamber (21) and the at least one venting port (17) being fluidically connected to the collapsible infusion chamber (21) at a level above said flushing port (7), for simultaneously allowing air from said collapsible infusion liquid chamber (21) to enter said flushing liquid chamber (2) and flushing liquid from said flushing liquid chamber (2) to enter collapsible infusion liquid chamber (21) when, during use of IV bag (20), the level of IV liquid in collapsible infusion liquid chamber (21) has become lower than the at least one venting port (17), thereby allowing the flushing liquid chamber (2) to be drained at least partially by gravity into the collapsible infusion liquid chamber (21);
• said at least one flushing port (7) forming a permanently open fluidic connection between said flushing liquid chamber (2) and said fluid flow path,
• the at least one venting port (17) forming a permanently open fluidic connection between said flushing liquid chamber (2) and said collapsible infusion liquid chamber (21).