Abstract: The present invention relates to a device containing a tube for a varied flow, comprising a tube being fixed in both its ends, whereby the tube is arranged to be stretched or shortened by longing or shortening of the distance between said attachment points.

Abstract: Pressure infusion apparatus (10) of the type that includes a chamber (13) for at least one infusion bag (21). In the chamber a pressure apparatus (18) applies pressure on the infusion bag to press out infusion liquid through an infusion tube (24). The pressure apparatus (18) includes a pneumatic pressure chamber (25) and a pressure source (27). Between the pressure storage chamber (25) and the pressure source (27) there is a pressure reduction valve (26) that significantly reduces the pressure in the pressure source (27) relative to the maximum loading pressure in the pressure storage chamber (25). The pressure source (27) includes an essentially unstretchable, air tight, flexible membrane (27a) which divides the chamber (13) into an infusion chamber and a pressure chamber (27b) and which presses directly on the bag (21). At least one flow regulating valve (28) giving a calibrated flow per unit time is attached to the infusion tube (24) or its extension from the infusion bag (21).