Materials selection for a heat exchagner.
Materials selection for a heat exchagner.
(OP)
Heat exchanger shell side: cooling water (Maximum Operating Temp. 40C). The cooling water has 1500ppm maximum Chloride and 60 wppm Oxygen.
Heat exchanger tube side: caustic (Maximum Tperating Temp. 146C).
We selected carbon steel for the shell and alloy 600 for the tubes.
In order to avoid the galvanic corrosion, we can not use carbon steel for the baffle (Cross).
My question is if we can use 304 or 316 stainless steel for the baffle. Considering the temperature (40C) and non pressure bearing, we do not need to worry about the stress corrosion cracking induced by chloride.
Heat exchanger tube side: caustic (Maximum Tperating Temp. 146C).
We selected carbon steel for the shell and alloy 600 for the tubes.
In order to avoid the galvanic corrosion, we can not use carbon steel for the baffle (Cross).
My question is if we can use 304 or 316 stainless steel for the baffle. Considering the temperature (40C) and non pressure bearing, we do not need to worry about the stress corrosion cracking induced by chloride.





RE: Materials selection for a heat exchagner.
That part aside, why don't you look at 2205 for the internals. It won't cost much more and it will actually hold up.
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Plymouth Tube
RE: Materials selection for a heat exchagner.
- Baffles : The severe crevice and pitting corrosion at the gap between tube outsides and baffle holes in 304/316 SS baffles expected. It may create a vibration issue. 2205DSS (or same as tubes’) is recommended.
RE: Materials selection for a heat exchagner.
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Plymouth Tube
RE: Materials selection for a heat exchagner.
Depending on the caustic concentration- it is common to use carbon steel (to ASTM A179) in heat exchangers operating up to 145degC in alumina refineries and up to 175degC over long periods (plants in service >20yrs). It does depend however on the free caustic concentration.
Cheers
RE: Materials selection for a heat exchagner.
regards
Luis Marques
RE: Materials selection for a heat exchagner.
RE: Materials selection for a heat exchagner.
That's not to say it isn't done elsewhere (146degC and 10% caustic).
Cheers.