Tank deformation

Testing for leaks in this way is very dangerous; there must be considerable pressure inside to cause such a situation. It’s difficult to restore; try filling it with water.

It was probably caused by improper operation. Has the cause of the accident been identified? As you said, it could be a problem with the welding at the bottom of the storage tank, or it might be due to incorrect calculations. I don’t know what substance is stored there; it would be best to redo the work

I don’t understand why you need to inflate the tank to test for leaks; it’s a bit dangerous. The tank is designed to hold liquids, not gases, and the forces exerted on the tank by liquids and gases are completely different. Gases introduce an additional axial force, and it is this extra force that causes the tank to deform. You can reinstall the bottom plate.

Remove the bottom plate and weld a new one; non-destructive testing should also be carried out on the welds in other areas

Is it a flat-bottomed tank? Could you send a photo? Also, using nitrogen for pressure testing poses a risk of asphyxiation

It’s a flat-bottomed pot. Circular. The bottom is completely bulged, with the edges rising upward by 300, and there is a positional offset.

Replacing the tank bottom plate is the best solution; if you find it troublesome, cut the large corner seams of the tank bottom, then cut the welds of the edge plates according to the actual situation, reshape the bottom plate, and weld it again. Final water filling test.

This phenomenon is known as \"flying jar\"; it occurs most often when the air pressure inside the tube is high and there is little material present. It results from the axial force exerted by the pressure on the cross-section of the jar being greater than the weight of the material inside the jar plus the load from the bolts. This phenomenon occurred several times in petrochemical companies years ago, but it rarely happens now. There may be two reasons for this phenomenon: 1. Design-related reasons. I see that there are bolt connections, and the design should have been validated through calculations. The pressure testing was not carried out as required, which led to excessive instantaneous pressure

Does the tank store liquid or gas? Is there any pressure? What is your test pressure, and what is the diameter of the tank? Based on its volume, the diameter must be at least ten meters; having only 24 foot bolts seems far too few! A one-meter tower has even more than that. Moreover, several beams need to be welded to the base for reinforcement! It is best to have experts take a look first to determine whether the design of this storage tank meets the required standards. If it does, repairs can be carried out by appropriately cutting open the bottom of the tank, using external force to straighten the bottom plate, and then welding it back together. Several steel sections can be welded to the upper surface of the base plate for reinforcement. A sealing test is necessary; to prevent deformation, it is recommended to first apply a certain amount of water pressure to hold the base plate in place, and then fill the remaining space with air to conduct the leak test

The large corner seam at the bottom of the tank can be cut open, and then the welds on the edge plates can be cut as appropriate; after shaping the bottom plate, it can be welded again. Then, a vacuum leak test is conducted on the bottom plate of the tank, followed by a water filling test. The final remediation plan should be determined based on the degree of deformation.

What medium is inside the tank? What are the process conditions? Is it necessary to conduct pressure tests and airtightness tests? If it is a pressure vessel, there are requirements regarding the pressure used for the pressure test, and this test has already been carried out during the factory inspection. If it’s not a design issue, it’s an operational error – the pressure exceeded the limit. The plate thickness is 8 mm; it seems that the design pressure you’re using isn’t very high! This post was last edited by yang8939 on 2009-2-16 22:57.]

I encountered the same problem – the bottom edge was raised by 50 mm. How did the original poster deal with it?

We encountered the same problem before as well; we learned* it

I just want to say that the wall thickness is a bit thin, and the pressure load exceeds what the tank can withstand. If we use 16mm, this problem doesn’t occur

Repairing this tank is likely to cost just as much as manufacturing it from scratch, and the construction time will not be reduced significantly either. Originally, such storage tanks were not allowed to be tested for leaks using air pressure, as this is equivalent to a pressure test, and storage tanks at normal pressure cannot withstand it. The deformation of the storage tank is likely to affect not only the bottom of the tank, but also the top and the pipe walls.