Abstract: The present invention relates to a failure alarm system for an intravenous feeding pump in which the pumping force is secured by the projection of a plunger into a chamber filled with the liquid to be pumped, which plunger is encased in a tightly fitting sheath of elastic material. In such a pump, actuation is secured by the application of a force from an actuator to the end of the plunger extending without the wall of a pumping chamber and the return force is secured by the elasticity of the sheath. The actuator of such a pump provides an actuator which can be selectively set to provide an extended range of operations per unit of time and can be modified to control the amount of projection into the pumping chamber by the plunger. In such a combination means is provided by the present invention for sensing the fact that there is a negative pressure, or suction, in the system that is not balanced by the in-flow of liquid, i.e.