Regarding the design service life of pressure vessels
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When working on projects, we encounter the following issue: The contract stipulates that the service life of pressure vessels is 40 years； Therefore, when designing the fund raising, we require a design life of 40 years. But our subcontractors refuse to indicate a design life of 40 years on the drawings ； They still use those regulatory requirements against us, saying the heat exchanger has a lifespan of 8 years and the tank has a lifespan of 15 years. The specifications clearly state that the design life of the tank is not less than 15 years. They also threatened us, saying that if we wrote about 40 years, they wouldn’t provide the design. I’m dizzy. Has anyone encountered this situation? To meet regulatory requirements, the design agencies aim to keep the design lifespan as low as possible. But the technical requirements of the users also need to be met, right? Why is that design firm so sensitive to the design life?
How is it possible to have containers that have been squeezed for forty years?
So what material is this device made of? What is the corrosion allowance! If it is uniform corrosion, the remaining corrosion allowance = corrosion rate (mm/year) x time period. The corrosion allowance of your device is really high, isn’t it? ! Why does any equipment have to last forty years? It is usually a cycle of 15 years.
Yeah, why use 40 years? Haha. No wonder they won’t design it for you; I wouldn’t agree either.
The design life should be related to the engineering installation; if the entire installation is discarded after 10 years, what’s the point of having individual equipment with a service life of 50 years? The determination of the design life is also closely related to operating conditions and the materials chosen for design. Generally, ordinary containers have a design life of 8-10 years, while tower equipment has a design life of 15-20 years; it is rare for such structures to last more than 20 years. The design life should be set reasonably.
Reply to 3# Xiaoxiaobao521: Equipment for nuclear power generation, with a required lifespan of 40 years
Reply to 5# qianshixu: Equipment for nuclear power plants is required to last 40 years; it seems like you don’t know much about this.
It also depends on whether the technology is advanced or not. Times are changing rapidly; even if a design is meant to last 40 years, high energy consumption means it will inevitably need to be replaced
Reply to 7# VINELI: I haven’t been involved with nuclear power at all, so I don’t know anything about it! !
I think the key is that you should provide them with detailed information on the corrosion rate, and there must also be a formal document. It can’t be like the equipment designed for normal use; after all, it’s meant to last 40 years, and such equipment has extremely high costs
As long as the equipment can be maintained and replaced, a lifespan of 15 years can be specified; after all, this container is subject to inspection in accordance with relevant container regulations, and other inspection standards can also be used if applicable. If 40 years is specified, the thickness of the corrosion allowance must be increased; if it is 2 mm for 10 years, it needs to be increased to 8 mm for 40 years.