Amine systems are extremely corrosive due to the acid-gas concentrations and the high temperatures. It is important that all carbon steel exposed to the amine be stress-relieved after the completion of welding on the particular piece. A system fabricated from stress-relieved carbon steel for DEA solutions, as recommended, will not suffer excessive corrosion. For MEA systems, corrosion-resistant metals (304 SS) should be used in the following areas:
1. Absorber trays or packing
2. Stripper trays or packing
3. Rich/Lean amine exchanger tubes
4. Any part of the reboiler tube bundle that may be exposed to the vapor phase
5. Reclaimer tube bundle
6. Pressure-reduction valve and pipe leading to the flash tank
7. Pipe from the rich/lean exchange to the stripper inlet