RUPTURE OF A GAS-PRESSURIZED CYLINDRICAL PRESSURE-VESSEL - THE VELOCITY OF ROCKETING FRAGMENTS

If a cylindrical vessel containing high pressure gas ruptures, missiles (i.e. vessel fragments with significant kinetic energy) may be generated and equipment in the vicinity put at risk. When a vessel is severed by a circumferential fracture the resulting sections undergo a rocket-like acceleration as the fluid contents escape. The velocity achieved by such 'rocket' missiles is dictated by the internal pressure history during the venting process, which is a function of the rate of breach development. Where the breach develops slowly the internal pressure remains essentially uniform during the depressurization process, whereas the internal pressure history for the rapid breach development case is dominated by wave action. Theoretical models are developed to predict 'rocket' velocities for these extremes assuming the break is adjacent to the vessel end-cap. The predicted velocities are compared with experimental data. Methods whereby the end-break data can be used to determine 'rocket' velocities when the break is in the central region of the vessel are then described.