This paper sums up five years of research and development focused on producing composite pressure vessel prototypes for the transportation of substances in powder form. Twenty years ago, Spitzer Eurovrac, a European leader in bulk powder transportation, was one of the first to consider replacing stainless steel with aluminium for this kind of vessel. They successfully reduced the weight of the vessel and then, a few years later, the weight of the trailer chassis. Since 2002, the company has been preparing the transfer from metal to composite with the support of Cetim-Cermat for design, calculation and process development.