The safe operating life of isothermal steel vessels for dock storages of liquid ammonia

摘要

The report considers the problems of life evaluation for the steel isothermal vessels intended for storing of liquid ammonia in connection with their operating conditions. It was determined that in the process of long-term service ( up to 30 years) the stress-corrosion damages and structural changes of metal and welded joints of the internal vessel filled with liquid ammonia do not take place. Formation and growth of fatigue cracks as a result of cyclic loading caused by change in height of product filling are regarded as the main probable factor of vessel material damageability. The possibility of normative period refinement for periodical inspection of technical state of ammonia storages with emptying of internal vessel from product is shown by the example of operating life calculation of typical isothermal storage of liquid ammonia with a volume of 20,000 m~3.