Corrosion Allowance
Corrosion Allowance
(OP)
This is the first time I ever saw below expression in a spec,
could you pls. advice how could I handle it?
Manufacturers shall conform the Corrosion
allowance of 3mm within the thickness
achievable as per the Design Standard of the
valve.
Type is high performance butterfly valves.
Thanks
could you pls. advice how could I handle it?
Manufacturers shall conform the Corrosion
allowance of 3mm within the thickness
achievable as per the Design Standard of the
valve.
Type is high performance butterfly valves.
Thanks





RE: Corrosion Allowance
My only interpretation of what you've stated is that they intend to have corrosion allowance applied on top of your specified thickness/schedule taking into account mill undertolerance. What is the particular item you are specifying? Pipe/Valves/etc... More elaboration is needed to provide a decent answer.
I appreciate your effort in accurately wording your issue although it does add a slight confusion. Can anyone else provide their opinion?
Thanks,
Ehzin
RE: Corrosion Allowance
Looks like someone has used 'Google Translator' to build up this statement.
Ehzin is right. Min Wall thk = Design standard wall thk + 3mm corrosion allowance
Cheers !!!
RE: Corrosion Allowance
These are fire safe valves with CAS bosy and we have proper coating etc. however
I could opine what I should do with this request.
RE: Corrosion Allowance
This corrosion allowance requirement is typically directly transferred from their Piping specification.
As a vendor, it will also give you an indication on the process fluid. Example: If an end user states 6mm corrosion allowance required then the valve material definitely should not be carbon steel.
RE: Corrosion Allowance
Cheers,
John
RE: Corrosion Allowance
RE: Corrosion Allowance
RE: Corrosion Allowance
Other replies on what the minimum tw should be are also correct in terms of piping specs for, say, elbows, pipe and tee's. For valves i think its not like that.
Convince your customer that what they need you to do is source valves that have internals, for the moving and sealing parts at least, that are corrosion resistant for the intended fluid. Other parts of the valve may have some corrosion allowance, as long as theyre parts that dont influence the sealing and shutoff/-on capacity of the valve.