HEAT TREATMENT (NH3 - ANHYDROUS - GAS)
HEAT TREATMENT (NH3 - ANHYDROUS - GAS)
(OP)
Hi,
I have a tank made from carbon steel type SA516 Gr. 60 with thk. = 10 mm (0,4 inch). The question is, heat treatment for welds of the tank shall be applied or not?
I have a tank made from carbon steel type SA516 Gr. 60 with thk. = 10 mm (0,4 inch). The question is, heat treatment for welds of the tank shall be applied or not?





RE: HEAT TREATMENT (NH3 - ANHYDROUS - GAS)
RE: HEAT TREATMENT (NH3 - ANHYDROUS - GAS)
Annealing of carbon steel pressure vessels in anhydrous ammonia service is recommended to mitigate the long term effects of SCC..
An ANSI "K" series standard(ANSI K61.1)exists for pressure vessels in anhydrous ammonia service.
You should be aware of and follow the current ANSI-K61.1 Standard, "Safety Requirements for the Storage and . Handling of Anhydrous Ammonia", or applicable Ammonia Manufacturing.
Alos see these links:
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http://www.tannerind.com/sto-anh-ammonia.html
Please complete this thread and let us know about your final design...
-MJC
RE: HEAT TREATMENT (NH3 - ANHYDROUS - GAS)
I have following conditions: MAWP = 12 bar (174 psi), and MAWT = 50°C (122 F).
RE: HEAT TREATMENT (NH3 - ANHYDROUS - GAS)
For parameters as were sent last time for anhydrous ammonia (NH3) and after read your comments I think that PWHT is not required. But, I am not sure for 100%.
RE: HEAT TREATMENT (NH3 - ANHYDROUS - GAS)
In case destination's law requires you consider Ammonia as a lethal substance, thus, you fall into UW-2 Service Restrictions who require you PWHT regardless to SCC considerations.
You may find further useful info (not only for PWHT) at the Handbook of Compressed Gasses (CGA Inc.):
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