In this paper, the results of long-range testing of
pressure vessels, and especially the spherical storage tanks made of fine-grain
micro-alloyed steels have been analysed. Special attention has been paid to the
results confirming that multiple cold-water pressure testing of the equipment in
service can be a cause of crack occurrence, especially so if the proof pressure
equals to that prescribed for new equipment.
Final conclusions are not derived, since the aim of the
paper is to give data to DIVK Commission for proof pressure test, which can
enable to elaborate the recommendations for equipment inspection and acceptance
in service and after repair.
Keywords: pressurized equipment, European
directives, pressure proof test, structural integrity