Does internal thinning and external thinning of the head affect strength?
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Head thickness 12, shell thickness 8, atmospheric pressure oil storage tank. When welding the head to the cylinder, does thinning the inside of the head or thinning its outside affect the strength of the head? The appearance is more aesthetically pleasing with internal thinning; aside from that, what are the similarities and differences between the two types of thinning? Thank you!
This post was last edited by Si Rongtao on 2009-8-21 at 14:47. Inner thinning and outer thinning of the head have no impact on strength. If the head is not thinned, the misalignment amount of the weld joint between the head and the cylinder exceeds the allowable limits; therefore, the head must be thinned in order to meet standard requirements. Inner thinning of the head also results in a more aesthetically pleasing appearance of the finished product.
This post was last edited by prt0683 on 2009-8-22 at 17:00. If we have to say which design offers better safety, my personal opinion is that it’s better to thin the outer wall of a pressure vessel under internal pressure or the inner wall of a pressure vessel under external pressure. At the junction between the head and the cylinder, in addition to circumferential and longitudinal tensile or compressive stresses, there are also bending stresses. Sudden changes in the shape of the structure are not conducive to resisting bending stresses... So, as mentioned above...
Since most end caps have straight edges, their inner or outer diameter is equal to that of the cylinder. If the thickness of the end cap is greater than that of the cylinder, in order to ensure a good fit, it is necessary to thin either the inside or the outside of the end cap; this however will affect the strength of that part of the end cap. However, if the material of the end cap is the same as that of the cylinder and the stress levels are identical, then this will not affect performance. But if the materials of the end cap and the cylinder are different, or if the stress levels differ, it is not possible to thin the inside or outside of the end cap; in such cases, welds must be added on the cylinder itself.
It doesn’t matter; the main consideration is ease of manufacturing
It is best to avoid edge trimming, carry out surfacing for transition, and then weld for strength.
Thinning does affect strength, but it’s not a significant issue given the usage conditions mentioned by the original poster. Additionally, thinning is mainly done to reduce stress concentration. For reference only.
This post was last edited by SHISHOUHUA on 2009-8-23 at 14:19. It is a measure taken to ensure that materials of varying thicknesses can be welded together, and it has no impact on strength
When welding the head to the cylinder, the head needs to be thinned for welding, and whether thinning is done on the inside or outside has no impact on strength. Of course, it depends on whether you go for a flush outer diameter or a flush inner diameter; this determines whether thinning is done on the inside or the outside. Of course, aesthetic considerations also need to be taken into account.
Internal thinning or external thinning has no effect on strength, while external thinning can make the weld appearance neater and more attractive; given this additional advantage, external thinning should be used!
This post was last edited by JFTANG726 on 2009-8-24 at 12:36. Regarding what the original poster mentioned, it’s unclear whether the equipment is horizontal or vertical; why is the thickness of the head 4 mm greater than that of the cylinder? As for the reason for thickening the head, if the head and the cylinder are made of the same material, thinning it will not affect the strength.