Vascular phantoms can be used as in vitro test objects to explore flow behaviour in pathological conditions and novel ways of improving ultrasound diagnosis. This kind of phantom should be anatomically realistic both in terms of geometry, acoustic and physical properties. In particular, enhancing measurements reliability of in vitro models test needs a realistic physiological flow performed by a reliable phantom setup. This paper describes the design of a programmable flow pump system, designed to be used in an in vitro experimental studies. This system wants to overcome budget problem due mainly to expensive flowmeters. The proposed solution is to use a low cost device, not able to perform a reliable closed loop control, but suitable to obtain an ARX non-linear model of the hydraulic circuit thanks to Matlab tools. By using that model, it is possible to act an open loop control able to produce the targeted waveform with median deviation less than 9% and a similarity index of 0.98. Here, we present also the flow rate calibration steps of the designed flow phantom setup. In the current work, the flow pump system has been developed using Carotid artery Phantom (CaP), but thanks of its programmability it's possible to implement different flow profiles suitable for others flow phantoms.