3 Questions about an API 12C AST Inspection
3 Questions about an API 12C AST Inspection
(OP)
An external inspection revealed :
1)A portion of the bottom of the tank projecting beyond the outside shell has been reduced to 1/2" from an original 1 7/8" or thereabout. Is this a matter of importance to the integrity of the shell to bottom joint?
2) Is this projection part of the critical zone?
3) This tank was erected on a sand base and this base is being eroded by rain exposing the underside of the projection by a 1/4". Would replacing this missing sand and compacting it with a hand held vibratory compactor (or jumping jack) work adquately? Any suggested procedure is welcome!!
1)A portion of the bottom of the tank projecting beyond the outside shell has been reduced to 1/2" from an original 1 7/8" or thereabout. Is this a matter of importance to the integrity of the shell to bottom joint?
2) Is this projection part of the critical zone?
3) This tank was erected on a sand base and this base is being eroded by rain exposing the underside of the projection by a 1/4". Would replacing this missing sand and compacting it with a hand held vibratory compactor (or jumping jack) work adquately? Any suggested procedure is welcome!!





RE: 3 Questions about an API 12C AST Inspection
1) The required chime projection is now 3/8", so the 1/2" spounds fine. It must have a thickness of 0.10" to need the Code requirements.
2) No, the chime is not part of the critical zone
3) You may find that "ramming" backfill material under the chime with a 2x4 may give better results before using the jumping jack.
Joe Tank
RE: 3 Questions about an API 12C AST Inspection