How should we understand “containers that cannot be internally inspected due to structural reasons”?
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Article 3.1.4.4.2(3) of TSG21-2019: “Containers that cannot be inspected internally due to structural reasons.” Do containers with a small inner diameter that do not require the installation of manholes or access holes fall within the scope of the aforementioned containers? Whether to follow this principle by indicating the calculated thickness on the construction drawings and specifying the requirement for regular inspections during use.
This refers to devices with special internal structures, such as fixed-tube-sheet heat exchangers. As for small containers, those that lack manholes but have nozzles that can be used as inspection holes do not fall into this category either.
Some devices with linings also fall into this category.
Some devices with internal fillers cannot be inspected internally. When the equipment is too small to be accessed, or when the diameter of the pipes does not allow for the creation of inspection holes, this rule must be followed. Special attention should be paid to specifying the relevant technical requirements; the minimum thickness indicated in the drawings takes into account factors such as reinforcement due to openings and supports, and it should not merely be a calculated thickness.
Does Article 3.1.4.4.2(3) of the Greater Capacity Regulations not stipulate that indicating the calculated thickness is sufficient? Why still need to consider issues like opening reinforcements?
We consider that what needs to be indicated in the diagram is the minimum thickness required to ensure the safe use of the equipment; therefore, there are many factors to take into account, and indicating only the calculated thickness seems insufficient.
You’re welcome; everyone should share their opinions for more references