Understanding of the provisions in GB/T150
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Clause 6.5.5 of GB/T150.4-2011 states that \"During assembly, the arrangement of welded joints on the shell shall meet the following requirements: a)\". . . b). . . c) In the assembled cylinder, the length of any individual section shall not be less than 300 mm. What is meant by the \"assembled cylinder\" mentioned in clause c)? For clamp-type kettle U-tube heat exchangers, with the additional short section of shell between the shell flange and the inclined cone, is it still necessary to meet the aforementioned requirements when the reinforcement length at the smaller end of the conical shell is less than 300 mm?
This post was last edited by fzujunru on 2018-2-5 at 18:36. The original intention of this rule is to prevent the use of scraps to assemble tube sections; it’s fine if the length of tube sections that do not need to be assembled is less than 300. That’s how I understand it
"In the assembled cylinder, the length of any individual section shall not be less than 300 mm; however, if the structure truly requires a length of less than 300 mm, it is not subject to this restriction. This clause clearly specifies the tube sections for assembling the cylinder.
If the cylinder body is assembled from two or more cylinder sections, the length of any single cylinder section shall not be less than 300 mm.
After looking at everyone’s opinions, it seems that this inclined cone cannot be considered a tube section; rather, it should be seen as two separate components that are assembled together, right?
Including the tube sheet sections of heat exchangers, their length can be less than 300 mm as long as the strength design requirements are met.
During the presentation, it was explained as follows for \"within the assembled cylinder\": I wrote it down: \"For cylinders that have only one section (such as heat exchanger tube boxes), there is no restriction on the length of that section\"”
I checked the explanatory notes for the GB150-2011 standard on pressure vessels; pages P229-P230 provide detailed explanations
The standard requirement is clear: \"In the assembled cylinder, the length of any individual section must not be less than 300 mm\"!