The present invention refers to a flexible multiple chamber bag comprising: a) three adjacent chambers, a first chamber partially separating a second upper chamber from a third lower chamber by first and second welded seams, b) said second chamber and said third chamber being partially connected by a third welded seam, c) said first welded seam being non-peelable and said second and third welded seams being peelable said second and third welded seams having the shape of an inverse letter “V” each second and third welded seam starting at the basic point of said “V” and terminating essentially in a right angle at the circumference weld of said bag, said bag comprising a hanger flap extending from the top end of said bag and a medical port welded to the lower end of said circumferential weld.