Clad Material Strength

[roca]

Morning All
When we have a clad vessel it is normal industry practise to ignore the clad material thickness when calculating the shell / head required wall thickness, nozzle reinforcement, etc. The clad material is treated as a corrosion allowance - even though in service the clad material may not even corrode.
In my past experience we have even added on to the required Code pressure thickness 1mm allowance for the clad material cut-back which is performed at longitudinal / circumferential weld seam joint preperations. This is of course a very conservative approach.
My question is where in the Code (ASME / BS / or any other) does it state that the clad material thickness SHALL NOT be taken into account when assessing the vessel design.

 

[prex]

Well, ASME VIII does not forbid to take into account the cladding, provided of course it meets some minimum criteria. In Div.1 see UG-26, but also part UCL, that is specifically devoted to clad materials. Div.2 also allows for design based on total thickness (AD-116).

prex

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[aybee]

refer UCL-23 (A)-(C) some times you include the cladding some times not, depends on the method of application