Not sure if this applies for the cut edges on the periphery of of repads but I'm not sure why it would not:
5.7.1.6 Sheared or oxygen-cut surfaces on manhole necks, nozzle necks, reinforcing plates, and shell-plate openings shall be made uniform and smooth, with the corners rounded except where...
If you have nothing positive to contribute to the topic of the forum, why participate? I get it that you may not think climate change exists or should not be addressed but the forum was created to talk about engineering solutions to climate change. If you don't think any effort should be...
There is a non-zero risk that is probably low but it is hard to quantify. If there is a change of service, tank lean, foundation settlement, external (pipe) loading, observation of corrosion or other change or detail that might affect the fitting then the risk goes up. You can try NDE, PMI and...
What is the function of the OLet? If you need a pressure tap maybe drill the flange or buy a drilled flange? If it has to be a branch connection, do you have room to put a short section of straight pipe there and then the elbow? You can also try to buy a long-tangent elbow which would have a...
Great discussion!
My 2 cents:
[ol 1]
the most productive path forward of all the above is to test it with actual loading
the best first order approximation is the difference between a straight line and curved length using uniform load defletion to etermine a circular or elliptical shape.
when it...
This design does not comply with many aspects of API 650 or 653.
The upper bottom must go through the tank shell.
API does not include the "rectangular bar profile" and is not clear what its material or function is besides being a corrosion accellerator
Self drilling screws are typically leaks...
Since you seem to be removing the entire bottom to dig out and remediate the contaminated soil under the bottom, going back with a single bottom over a liner and sand or concrete pad seems to be a good option. API does not mandate a double bottom.
Without additional tank / foundation / soils /...
I think it is becasue if your large, expensive, high capacity vessel has a hole in it the enigneers who wrote API 653 think should put a butt-welded patch in it and not fool around with lap patches that have a low joint efficiency as well as load path and/or other issues. Trying to guess why a...
If the tank is known to leak, it must be taken out of service immediately, without question or delay. All pollution must be remediated without delay. Those should be your first priorities.
The tank owner has a responsibility to the community to provide a secure place to store the product...
For API 12C tanks circa 1960, API 12C 15th edition 1958 includes this language regarding frangibility in the roof design section of the standard.
It would appear that you are on the right track, although the current standard has more details, requirements and restrictions. If you are...
I think you read API 653 correctly and there is no "out" for old equipment that has not failed yet. If you have found a potentially dangerous situation or weakness in a design feature it is your responsibility to let the owner know. The conditions that the tank is exposed to may have changed...
"I honestly think they haven't even fastened the plywood and simply put it on top of the beams."
This may not fly - the beams may roll or bend sideways without weak axis bracing, the posts may fall over.
"We can't use a steel plate of that size it would be too expensive I'm pretty sure"
You are not sure?
1/4" steel plate is cheap and it does not change anything else.
1" road plate is cheap and may be readily available.
Does the plywood fail in deflection?
In which case, who cares?
Can you add...
I would not flip the beam.
This beam shape would drive you nuts determining the allowable and actual stresses in each component.
It is intended to be used one way and if it fails you are left high and dry all on you own, an island amongst lawyers.
"I don't feel comfortable with a 9 inch...