Should the minimum forming thickness be specified for a flanged conical head?
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Some people believe that folding and shaping can result in thinning, so it is necessary to specify the minimum thickness to facilitate proper material cutting. Does it make sense?
That makes sense. But it hasn’t been marked. It seems that it’s indeed difficult to come to a definite conclusion regarding this issue. There is also loss during the heat rolling of the cylinder; so shouldn’t the minimum achievable thickness be specified as well?
At present, end caps generally specify a minimum forming thickness, which helps manufacturing plants to control the thickness of the material used, thereby avoiding unnecessary waste. Flanged conical heads are generally formed through spinning, resulting in more significant local thinning. If a minimum forming thickness is specified, material waste is reduced, and manufacturers can achieve better control over the thickness required for allowable stress levels as well as the thickness needed for post-weld heat treatment.
Since it’s a cover, it’s best to mark it.
There is definitely some thinning, it’s just that I’ve never seen it indicated. These days, a large margin is usually built in, so there’s no need to worry
This post was last edited by zjq1962 on 2018-4-14 09:21. It is not indicated on the drawings, but the amount of thinning due to the formation of the transition zone is taken into account during calculations. In the pattern part list, the thickness is indicated in the same way as for elliptical heads, showing the minimum formable thickness.
There is thinning in the transition sections, and the degree of thinning is actually quite significant; it’s best to indicate the minimum achievable thickness
How is the forming thickness of that transition section calculated? The standard doesn’t specify the thickness reduction amount, right?
If thinning occurs after processing, the minimum thickness should be indicated on the design drawings, so that the manufacturing party can take the material thickness into account.
It should be indicated (especially for end caps and thick plate materials). For some commonly used specifications, it is known from experience that there is generally no significant thinning in cold-formed tube sections, so it may not need to be specified on the drawings.