In the past we have always used a full fillet weld. I am curious as to why the top shell course would be 1/2" thick as usually it is only 1/4" as there is virtually no hydrostatic head and a thicker course is not required.
We have decided to replace the corroded sheet based on the following:
Per API-653, Section 9.10.1.2 Repairs Within the Critical Zone “The use of welded-on patch plates is permitted for repairing a portion of tank bottoms within the critical zone (see3.10 for definition) provided 9.10.1.1...
If you are using a tombstone patch to repair an area in the critical zone you have to follow API-653, 9.10.1.2. Point f states the bottom plate under the perimeter of a welded-on patch plate shall meet the thickness requirements in 4.4. If you have an isolated hole through a plate in the...
Depending on the height to diameter ratio (providing that the foundation can take the loading), designing for wind loading per API-650 may require anchors which has a cost impact. Sometimes by manipulating the size of the tank (height/diameter) you can avoid anchors if the design pressure of...
On an existing field storage tank, the tank is going to be jacked and leveled due to excessive settlement. Once leveled, the old annular plate will be removed and new annular plate will be installed. To mitigate future settlement, a concrete annular ring or the use of a bearing plate is being...
