how to prevent corrosion by inherently safer design?

[navycaptain]

Hi Folks:
This is my first time to raise a thread, if there is something wrong to disobey forum rules, please kindly get me noticed, thank you!
I'd like to discuss with you professional guys about how to prevent corrosion by inherently safer design. For example, there are some area which is prone to get corrosion: pipe eblow, weld seam/base plate welding zones on pipelines, relief valve and instrument sensor fittings and so on. please see tha attached file which describes the easily corrosion area.
even though the steel material selected based on chemical characterics(pH, viscosity, Temoperature, but still corrosion could occur at these parts, normally, when leakage happened or thickness measured by UV device, we can detect the thickness change on equipment. are there any way on design which can specially deal with the prone corrosion part? such like: increase the thickness of pipe elbow?
i'm opearting a chemical plant, i personnally believe that corrosion prevent design is the design institution responnsibilty.
hopefully, i make myself clear the question, thanks a lot!

 

[mk3223]

are there any way on design which can specially deal with the prone corrosion part? such like: increase the thickness of pipe elbow?

IMO, the part of the engineering work is always to deal with the material corrosion issue in term of the plant operation life, project budget, etc. A perfect, 100% corrosion free material is existed in a cost if it's really available.
It could be in one's wish list, but the reality could be in a very opposite way.

 

[don1980]

Internal corrosion is minimized by choosing the optimal vessel or pipe material. There are many more variables involved in minimizing external corrosion such as whether it's insulated, type of pipe supports, proper welding procedures, proper maintenance and painting program, materials selection for fasteners and attachments, etc.).

Corrosion minimization is one of the many details considered when corporate engineering practices/guidelines are developed. After a plant is built, corrosion is minimized by adhering to good maintenance practices (e.g. painting and leak prevention). There are lots of engineering design details aimed at preventing corrosion, which the reader may not recognize as being for that purpose. For example, requiring the use of welded pipe shoes instead of clamp-on shoes.

 

[rotw]

I think the concept of inherent safety is more directed towards the human action or behavior. Think of " system one / system two " concept dropped by D. Kahnemann. The system one is sort of instinctive human behavior. The system two is analytical. The system two is off by default in human brain so it has to be switched on or activated by a human intentional action.
As for the link with safety, inherent safety ackowledges the so called system 1 type of human behavior and attempt to mitigate consequences by taking appropriate measures. Example: if you have a child and you are boiling water on a apparatus with rear and front plates, you could disconnect (take them off or break them) the plates that are on the front where a drop of hot water is still possible and could cause harm to your child. In this case you are creating conditions that oblige you to use the rear plates only, say by design. So when your system 2 awareness is off and things go wrong you can fall back on something.
I dont understand very well the connection of inherent safety with corrosion which is more of a chemical phenomenon then the result of a human (e.g. operator) course of action - typically I would expect. Maybe a further clarification?

 

[moltenmetal]

Use corrosion-immune rather than merely corrosion-resistant materials whenever possible. Use free-draining design as free as possible of crevices. Select the right materials, and fabricate and passivate them properly. What more do you want here?