In high velocity flow pattern (<erosion velocity), the anhydrous ammonia may not have a specific synergetic effect to accelerate the corrosion while amine or ammonium bisulfide has an accelerative effect of corrosion.
The most critical issue will be Stress Corrosion Cracking, not a severe metal loss if the design is under the general erosion velocity limitation.
References
- NACE Publication 24061
- MTI MS-6