Vessel wall corrosion, increase

Tray deck, downcomer, and vessel wall corrosion is increased. Water conducts electricity a thousand times better than do liquid hydrocar-... 

Corrosion is generally considered to be in one of two forms uniform or localized. Uniform corrosion occurs evenly on all surface areas of a pressure vessel. Such corrosion occurring at slow rates is quite typical and can be planned for by increasing the original wall thickness design. For vessel systems with a predictable corrosion rate, allowances can be calculated for vessel life spans of 2-20 yr. ... 

Pressure vessels are subject to thinning by corrosion, erosion, or mechanical abrasion. To increase the desired useful life of the vessel, the design should include a suitable increase in wall thickness over the minimum design thickness required for safe pressure containment. In most cases, there is no specific code requirement for how much corrosion allowance a vessel requires. Vessels subject to corrosion should have provisions for complete draining as well as openings to allow for the inspection of internal surfaces. 

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