Difference between cladding and lining
Difference between cladding and lining
(OP)
Dear All,
What is the difference between cladding and lining? Can these two terms be used interchangeably?
Appendix 3 of the Code (ASME VIII-1) defines a “clad vessel” and a “lined vessel”. To me, it appears that the differences between these two terms is based only on whether the corrosion resistant material is integral/continuous (in case a clad vessel) or whether it is intermittent (in case a lined vessel). Is my interpretation correct?
Your opinions on this subject will be highly appreciated.
Regards,
jehan
What is the difference between cladding and lining? Can these two terms be used interchangeably?
Appendix 3 of the Code (ASME VIII-1) defines a “clad vessel” and a “lined vessel”. To me, it appears that the differences between these two terms is based only on whether the corrosion resistant material is integral/continuous (in case a clad vessel) or whether it is intermittent (in case a lined vessel). Is my interpretation correct?
Your opinions on this subject will be highly appreciated.
Regards,
jehan





RE: Difference between cladding and lining
Steve Jones
Materials & Corrosion Engineer
http://www.pdo.co.om/pdo/
RE: Difference between cladding and lining
Thanks for your reply. But now I have some other questions.
Based on your below reply, would it be ok to interpret that a lining is in a way a "mechanicaly inferior cladding" since it is attached by plug welds?
When is lining prefererred over cladding? What are the merits of lining over cladding?
Is cladding applicable for metals only and does lining include both metallic and non-metallic (example- plastic lined, FRP lined, etc) lining?
-Jehan
RE: Difference between cladding and lining
The choice of whether to go for lining or cladding is a function of all the usual input parameters in materials selection: cost, availability, schedule, fitness for service etc etc.
As to the last question, you really should study the wording of UCL-1 and not get confused with painting and coating terminology that ASME VIII does not address.
Steve Jones
Materials & Corrosion Engineer
http://www.pdo.co.om/pdo/
RE: Difference between cladding and lining
RE: Difference between cladding and lining
However in my experience the two terms are sometimes interchanged and can cause some confusion as some people call clad, “lining” – which I suppose is correct too.
I define it as:
CLAD:
Clad steel is a base carbon steel material (which takes the pressure and loads) covered with a corrosion resistant alloy (CRA) material.
The CRA can be either integrally bonded (i.e. explosive or hot roll bonded to the base carbon steel material) or applied by weld overlay deposit.
Although UCL-23c allows you take account of the claddings strength, I have never done this and most clients don’t allow it either. The cladding is just assumed as a corrosion allowance and no credit is taken for its strength in the pressure calculations.
The CRA material can also be applied as strip lining or as loose sleeves in pipes. However there is still welding involved here back to the base CS material. Strip or sleeve lining is not used as stated above in high temperature services or where there is vacuum pressure. Additionally sleeve lining is used in situations where CRA material cannot be or is difficult to integrally bond to the base CS.
LINING
Lining are loose non metallic linings (e.g. rubber, PTFE) or painted / sprayed coatings or glass linings. The glass or painted / sprayed coatings may also need to be cured at temperature.
The loose non-metallic linings are bonded to the base CS
Loose and coated / sprayed and glass linings will required attention to vessel internal surfaces, welds and nozzle corners which need to be of a smooth profile and radiused in accordance with the lining manufacturers or clients requirements,
Hope this helps
RE: Difference between cladding and lining
a star for you for clearly out"lining " the differces (!?!) between the two.
-jehan
RE: Difference between cladding and lining
I wish to share my experience with a cladded & lined vessel. If any one wishes to measure the thickness of shell using Ultrasonic method, on a cladded vessel & a lined vessel, the results would be as under:-
Cladded Vessel : Will get thickness of Shell + Clad
Lined Vessel : Will get Thickness of outer shell only.
This may sound simple but sometimes the info may be very useful.
RE: Difference between cladding and lining
Another reason is that cladding usually has to be stipped back prior to welding the carbon steel portion to ensure good weld quality. Lining is added afterward so this is not an issue.
-Christine