Warping around the bottom plate of the acid storage tank at the construction site
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Hello, everyone from CNOOC. I have a question for you: we have an acid storage tank with a diameter of 1.5 meters and a height of 2 meters. Its outer wall is made of carbon steel, while the inner wall is lined with plastic. There is a bottom plate at the bottom of the tank, and it has been in use. However, over the past couple of days, we noticed that the edges of the bottom plate have warped, by about 4 cm. The center of the bottom plate remains in contact with the foundation. Could anyone help us figure out what might be causing this?
During this process, pressure is generated by welding; therefore, the tank foundation needs to be designed with a slight arch shape.
When the feed is full, it will drop; the center of the storage tank will arch, and the repeated movement of feed and discharge can cause damage to the welds.
If the bottom of the tank is filled with sand, it’s best to check whether any is missing I have encountered situations where uneven bottom sediment caused the edges of the tank to lift up.
Since the tank is not large and there is no sand filling in the foundation – it’s just a regular concrete foundation – after applying anti-corrosion treatment, the equipment is placed there. Does this have anything to do with starting up production?
So it hasn’t been dealt with yet, as the reason is unclear. Is the warping related to the fillet welds at the corners of the wall panels and the bottom panel?
I’ve learned that. So what is the reason why the bottom plate is warping now?
Of course, there is a certain relationship, but it is mainly caused by the welding of the floor panel joints. In fact, this phenomenon occurs to some extent in storage tanks; it’s just a matter of the severity. It stems from the welding sequence when assembling the bottom plates, with no deliberate effort being made to control the generation and elimination of stress.
Was the deformation gradual or sudden? A visual inspection of the floor slab shows that it appears to be a single piece, with no joints
Is there a vent on top of the acid storage tank? Please check this; it’s possible that the acid has evaporated inside the tank, causing the acid tank to expand and leading to warping around the foundation. If there is a top vent, open the top vent valve