Yes and no. It depends - doesn't it always?
CSA recognizes ASME. In most instances, CSA will accept ASME cert flanges (with restrictions). If you meet the restrictions (and most times, we do), then you don't need the CSA cert - just use the ASME.
Now, of course, if you don't, then you are back to CSA certified flanges.
The opposite is not true. ASME does not recognize CSA. So, if you need to meet ASME code, like when flanging to pressure vessel, you will need dual cert flanges (otherwise, you will never be able to keep it all straight in your head).
Okay, I guess the answer is it is probably a good idea, assuming you can bear the cost.
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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