[MW:29762] Usage of SS304 tubes ot SS316L tubes in cooling water exchangers

Recently I observed that in one of the cooling water exchanger (tube in tube) which has Hydrogen at 230DegC on the outer tube and cooling water on the inner tube. The tube metallurgy was SS304.

Where as in another unit, a cooling water exchanger with SS 316L tubes had lean amine on shell side.

On what basis is 316L tubes chosen over 304 tubes when a cooling water exchanger is designed?

- I have two things in mind as far as corrosion is concerned, one being ClSCC and another being PTASCC.

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