Regarding the issue of the connection between the tube and the tube sheet
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For ammonia coolers, how is the connection between the tubes and the tube sheet typically made? We usually use welding combined with expansion fitting, but for liquid ammonia, stress corrosion occurs; therefore local heat treatment is required after welding. However, local heat treatment does not guarantee the effectiveness of the expansion fitting. Should expansion fitting be used? Is there any risk of crevice corrosion in liquid ammonia? Please have the sea friends discuss it.
Heat treatment has little effect on bonding expansion, but it affects strength expansion.
Is an ammonia cooler a pressure vessel used in refrigeration systems? It’s fine not to heat-treat the pipe fittings, just between us
No expansion bonding is required, and liquid ammonia does not suffer from crevice corrosion. (Personal opinion, for reference only)
We use expansion bonding, and we also perform post-weld heat treatment. (Maybe adding more than 2% water to liquid ammonia as a corrosion inhibitor!) Uncertain)
No heat treatment is required; what form should the condenser take? It doesn’t have to be a pressure vessel