CSA G40.21 Gr 350W plates API 650 carbon steel storage tanks

API 620 Tank Standard Post-heat Treatment (Stress Relief)
The post-heat treatment now performed on pressure vessels is of established value, although the mechanism by which the improvement is realized may be open to debate. Post-heat treatment of API 650 carbon steel storage tanks tank sections when the plate thickness exceeds 11/4 in. is required as stated in 5.25. In special cases, the possibilities of post-heat treatment after erection should be explored. Post-heating an insulated tank may be possible if an ample source of heat is readily available and if the rigidity of the tank is adequate.
The thermal stress-relief treatment performed on pressure vessels is recognized as a means for reducing the probability of brittle failures.

Fixed roof API 650 oil storage tank includes inner floating roof tank, which API 650 carbon steel storage tanks can effectively prevent sand, rain, snow or dust from polluting the storage liquid. Under various weather conditions, API 650 oil storage tank can ensure the quality of liquid storage, which is called "all-weather API 650 carbon steel storage tanks storage tank".

The main reason of "small breathing" loss of API 650 carbon steel storage tanks is the change of atmospheric temperature. When the temperature rises with the increase of solar radiation from dawn, the temperature of oil in the API 650 carbon steel storage tanks also changes, resulting in the acceleration of evaporation speed and the increase of evaporation pressure. When the pressure exceeds the positive pressure rating of the breathing valve, the oil-gas mixture in the API 650 carbon steel storage tanks is discharged into the atmosphere through the breathing valve, which is the "exhalation" process of the oil tank.