Corrosion Allowance on Inner Pipe of a Double Pipe Heat Exchanger

[yl0525]

Could anyone please advise me on which Code or Standard has stated that the corrosion allowance does not need to be considered for the inner pipe of a double pipe exchanger?

Additional, I have an exchanger design consisted of a few series of double pipes. The inner pipe will be extended out of the outer pipe connected to flanges & U-bend to continue to another bank. For the channel part that are outside of the outer pipe i.e. the extended portion of inner pipe, the tubeside flanges and the U-bend pipe, do we need to consider corrosion allowance in my mechanical calculation?

Thank you,
yl0525

 

[SnTMan]

yl0525, I doubt you will find a Code specifying a corrosion allowance. Standards may or may not, TEMA does, based on TEMA class. Are you working to any Code or standard?

CA will usually be based on service conditions and desired life.

Regards,

Mike