钢板负偏差为0.3mm计算的时候需不需要考虑

难念的经

UG-16（c）中当板材标准允许有更大的下偏差时，则材料的订货厚度应足够的大于设计厚度，这半句还能明白，最后半句不明白了，求大神指教。。。。

asnt2012

Interpretation:           VIII-78-27
Subject:  Section VIII, Division 1,UCS-56(d)(4)
Date Issued:  February 7, 1978
File:              BC77-860


Question:      Under UCS-56(d)(4) it is indicated that,with the exception of Fig. UW-16.1, sketches (a) and (b), the criteria for establishingthe thickness to be used in applying the requirements for postweld heattreatment is the thickness of the shell or head plate in nozzle attachmentwelds.  May the ordered thickness be usedfor establishing this criteria?


Reply:           Yes. See also UG-16(c).




Interpretation:           VIII-80-70
Subject:  SectionVIII, Division 1, UG-16(c) and UG-32(a), Tolerance on Plate Thickness
Date Issued:  August 8, 1980
File:              BC79-322


Question:     Assumethat in accordance with footnote 12 of UG-32 Section VIII, Division 1, a platewhich is to be formed into a head is ordered with a forming allowance consideredappropriate for the application but without an additional allowance for millunder tolerances on the plate.  Afterforming, the head is found to have a minimum thickness less than required byUG-32. May the undertolerance permitted by UG-16(c) be applied to the minimumthickness calculations, and if the actual minimum thickness is within thislimit, may the head be used at the design pressure corresponding to thecalculated minimum thickness?


Reply:           Yes.




Interpretation:           VIII-80-76
Subject:  SectionVIII, Division 1, UG-16(b) and (c), Sheet Tolerance
Date Issued:  August 15, 1980
File:              BC80-194


Question:      Isit the intent of UG-16(b) to establish a minimum thickness of 1/16 in. withoutallowance for undertolerance?


Reply:           No.The undertolerances of UG-16(c) may be applied to the minimum thickness ofUG-16(b).  We caution you to observe thewarning in the last sentence of UG-16(c) which points out that some materialspecifications permit greater undertolerances than permitted in UG-16(c).




Interpretation:           VIII-1-86-67
Subject:  SectionVIII, Division 1; UG--16(c)
Date Issued:  May 13, 1986
File:              BC86-240


Question:      Astainless steel pressure vessel is being fabricated with no corrosion allowancespecified.  The plate material ordered isequal to the design thickness. Can the plate material be accepted and used inthe vessel with the mill undertolerance values given in UG-16(c) if thethickness is less than required by the calculations of UG-27?


Reply:          Yes.




Interpretation:           VIII-1-92-216
Subject:  SectionVIII, Division 1 (1992 Edition, 1992 Addenda); UG-16(b)(4) and (c)
Date Issued:  May24, 1994
File:              BC93-718


Question:      Anair tank is constructed to the minimum required thickness of 3/32, in. as givenin UG-16(b)(4) of Section VIII, Division 1; may a formed head with a 6% undertolerance,as described in UG-16(c), be used in the construction?


Reply:          Yes.




Interpretation:          VIII-1-04-92
Subject:             Section VIII,Division 1 (2004 Edition, 2005 Addenda); UG-16(c)
Date Issued:       April 27, 2006
File:             BC06-357


Question:     A pressure vesselthat has no specified corrosion allowance is made of plate that is ordered to athickness equal to the required design thickness. If the actual plate thicknessreceived is less than the required design thickness, but is within theallowable under-tolerance as given in UG-16(c); may the plate be used inaccordance with the rules of Section VIII Division 1?


Reply: Yes.

本大风

建议看英文原版，UG16（c）首先规定实际用来制造容器的板材其厚度负偏差不得大于0.01in与6%订购的板材厚度规格两个数值当中较小者，当遇到板材厚度负偏差大于0.01in与6%订购的板材厚度规格两个数值当中较小者的情况时，为了能够满足“第一句”中的要求，就要订购够更厚规格的板材，比如设计厚度是5mm，但是钢板供应方5mm板材的负偏差大于0.254mm，此时必须要订购6mm或者更大厚度规格的板材。

xiaoshugenliu

第1卷中，AI将我计算书中的壁厚负偏差删掉了，但我觉得应该考虑才对。

xiaoni1983

应该不需要吧，这个应该允许有误差

rivera

如果是0.25MM，可以不考虑

难念的经

本大风 发表于 2016-5-13 16:25
建议看英文原版，UG16（c）首先规定实际用来制造容器的板材其厚度负偏差不得大于0.01in与6%订购的板材厚度 ...

C:\Users\Administrator\Desktop划红线的英文怎么翻译啊。。。求指教

难念的经

rivera 发表于 2016-5-14 00:38
如果是0.25MM，可以不考虑

我也知道0.25不考虑

inconel

as per code, generally max. allowed under tolerance is smaller value of 0.25mm or 6% of the ordered thickness.

If, any material specification allows larger under tolerance than ASME Sec-VIII, then the material shall be ordered to a higher thickness value, so that the final under tolerance shall not go below 0.25mm value.

design thickness is different and ordered thickness is different. under tolerance value will be added to design thickness to get the final thickness for safe equipment operation.

难念的经

inconel 发表于 2016-5-14 11:21
as per code, generally max. allowed under tolerance is smaller value of 0.25mm or 6% of the ordered  ...

那我在开孔补强的时候就要考虑负偏差呗？看到之前那个截图了么 划红线的句子该怎么翻译啊，大神

8341fghy

不同的厚度等级，偏差不一样，常用的是要考虑的！