CSA G40.21 Gr 350WT plates API Std 650 larger diameter tanks

The API Std 650 larger diameter tanks must go through strict inspection before putting into use. Inspection of plate groove of API Std 650 larger diameter tanks, vertical oil tank: After finishing the groove processing of oil tank plate, it is necessary to conduct dye penetrant inspection on the groove. This process is mainly aimed at the hard damage of groove in the machining process and the defects of the plate itself. If any defect is found, it shall be processed again until the defect disappears.

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 Std 650 larger diameter 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.

Before pressure testing, thoroughly flush the API 650 tank floating roof primary drain hose system. Supply API Std 650 larger diameter tanks blind flanges, gaskets, and bolting (for other types of blanking covers as may be required) necessary for testing.