Regarding the use of national standard flanges
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I would like to ask: if I design an atmospheric storage tank in accordance with NB/T47003.1 and use national standard flanges, what will be the consequences, and are there any additional measures that need to be taken?
For vessels at atmospheric pressure, there are no requirements regarding flanges
Just use it normally; what consequences could there be?
Under normal use, if the wall thickness of the storage tank is too small, check the calculation documents to determine whether reinforcement ribs are needed
Small connectors have little impact, but for larger connectors, it becomes necessary to consider the combination of the connector wall thickness and the weight of the flange. For example, it’s not possible to use a connector with a diameter of 530, 5, or 6 mm together with a flange that weighs 500 kg; there might even be another flange cover weighing 500 kg as well, which could serve as an access hatch or a spare opening for process purposes
Generally speaking, if the equipment uses flanges that comply with national standards, then the pipeline flanges should also meet those standards; or it is necessary to verify whether they can be connected to flanges that meet national standards, as the equipment needs to be connected to external pipelines
According to Clause 7.2.4 of NB/T47003.1-2009, \"Steel pipe flanges, gaskets, and fasteners should preferably be selected in accordance with HG/T20592～20635.\" ”. It is also stated here that it is appropriate; in other words, other standards can also be considered for use. It is necessary to check whether the requirements of the relevant flange standards regarding the applicable range of flanges are met.
For atmospheric-pressure containers, as long as they meet the stiffness requirements and do not leak, that’s sufficient. When using national standard flanges, the minimum nominal pressure should be 0.25 kilograms; of course, such flanges can be used
What’s wrong with national standard flanges? In terms of the standards themselves, as well as the materials and inspection processes, they are somewhat lower than those specified by the Ministry of Chemical Industry. But they can be used in vessels under normal pressure just fine
It doesn’t matter whether it is Chinese standards, American standards, or European standards; what’s important is that they match. Don’t do A on the left and B on the right, haha