Pressure vessel manhole thickness
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The operating temperature of the pressure vessel is 50 degrees, the pressure is 6.4 MPa, and the wall thickness is around 100 mm. However, the thickness of the manhole is about 500 mm. I would like to ask why there is such a large difference in thickness between the manhole and the vessel walls? I also want to ask everyone: as can be seen in the pictures, surfacing is being used in all cases. I would like to know under what circumstances we usually use surfacing – and why do we do that?
The thickness of a manhole cannot be 500 mm; the manhole section is connected to the container wall, and there are specified standards for the difference in thickness between the two.
I guess it will also be over 400 somewhere
It is unreasonable for the ratio of the takeover wall thickness to the cylinder thickness to exceed 2.
400mm thick? Are you sure? Let me do the calculations for you: for 500 manholes, we’ll assume an inner diameter of 500. If the thickness of the manhole cylinder is 400, then the diameter will be 500 + 400×2 = 1300. Go and measure it with a ruler again. It must be a mistake! I forgot to divide the cylinder thickness by 2!
Well, definitely, the diameter of that manhole is twice the thickness of its wall. The outer layer is carbon steel, with a layer of 316L stainless steel welded on top; I haven’t measured it, but it’s at least over 400 in thickness. I tried to climb inside – it was very difficult
There are heat-resistant bricks inside this, right? Was the thickness of the brick taken into account as well?
Without heat-resistant bricks, it is not a pressure vessel
The pressure isn’t too high, and the temperature isn’t high either; it seems the poster is referring to an inner diameter of 400 mm. There is a device with a design pressure of 11 MPa; the wall thickness of its DN450 manhole is 46.5 mm, which is mainly required for reinforcement through opening. The wall thickness mentioned by the poster seems a bit unreliable.