Generally when a Spherical Tank goes out of service for maintenance, most NDT and inspection activities are focused on the Pressure Vessel body. The support legs are also important components and they contribute to the global integrity of the Spherical Tank. Examination of the legs is mainly a visual examination of the outside fireproofing.
SONOPEC allows for a good evaluation of the integrity of Spherical Tank Support Legs through its fireproofing. When the support legs are not considered or not good examined, there may be serious consequences for the integrity of the structure that may collapse during a water test prior to its going back to service (Figure). Water is generally heavier than the liquefied gas product stored in this Pressure Vessels types.