How is the lifespan of pressure vessels calculated?

How did the original poster come up with this question? ! ! ! It is recommended to learn more *^_^ PS: I’ll help you transfer to the relevant section; maybe some experts there can answer your question.

The service life of the equipment is obtained by dividing the corrosion allowance used in calculating the wall thickness by the medium’s corrosion rate (the annual amount of corrosion, which can be found in relevant data).

It’s hard to calculate; haha, it’s very difficult to match it with the actual service life of the equipment! ! !

During design, the annual corrosion rate of the medium on the equipment materials should be determined first (there are various ways to obtain this value), followed by the determination of the equipment’s service life (major equipment such as towers and reactors should generally have a service life of at least 15 years, while ordinary equipment and heat exchangers should have a service life of at least 8 years). Finally, the corrosion allowance is calculated, which then enables the design thickness of the shell to be determined; I believe this is the proper sequence.

For stainless steel materials, if there is no corrosion or only minimal corrosion, how can the service life be determined?

Generally, it is 10 to 15 years; in cases of severe corrosion, it is 8 years

There are many issues related to the design life, and it’s not possible to explain them all at once. For example, it’s difficult to determine the corrosion allowance – in chemical production, it’s not possible to specify the medium used with precision, and such media are diverse and complex. Moreover, it’s not true that the corrosion allowance for stainless steel is 0; a material’s resistance to corrosion depends on factors such as the medium, temperature, pressure, and concentration. Saying that a material has a corrosion allowance of 0 in certain conditions doesn’t mean it won’t corrode at all, but rather that the degree of corrosion is negligible enough for the equipment to function properly. Of course, for designers, we generally do not specify a design life, but it is still taken into consideration in the design process, as the corrosion allowance is determined based on the service life. Typically, for important equipment such as towers, a corrosion allowance of 15 years is considered, while for heat exchangers, it is 8 years; of course, specific considerations should be given in actual design work.

I guess what the original poster is asking about is containers with no corrosion. These days, more and more containers are designed using stainless steel, and our company doesn’t specify a design life for them at all