SCC of ammonia storage tanks
SCC of ammonia storage tanks
(OP)
I have read that between 100ppm and 1000ppm of water should be added to liquid ammonia being stored in carbon steel tanks (-33 deg C and ambient pressure). How does the water addition eliminate the risk of SCC? Also, can SCC occur if there is no oxygen present?
Thanks in advance for your comments.
Thanks in advance for your comments.





RE: SCC of ammonia storage tanks
I am involved with the National Board Inspection Code main committee, and we deal with this issue. I have attached an interesting NBIC article that should be of interest to you;
http://www.nationalboard.net/classics/classic8.html
RE: SCC of ammonia storage tanks
RE: SCC of ammonia storage tanks
Thread330-79163
RE: SCC of ammonia storage tanks
Approx how large does a SCC crack have to be before it is picked up by a reputable AE operator? SCC cracks are intially very fine so is there potential to miss cracks in their initial stages? Although it would be costly and time consuming, should mag particle testing be carried out on welds also?
Cheers
RE: SCC of ammonia storage tanks
There is a specific program design for testing NH3 Spheres called Monpac. A lot of work on this program was done on our NH3 Spheres by Dr Fowler of Monsanto. These spheres stayed wired with tranducers until taken out of NH3 service.
The company that sells the AE programs and Equipment.
http://www.pacndt.com/index.aspx?go=technologies&focus=Technology%20Pkgs.htm
A company that does AE inspection.
http://www.matrixie.com/nh3.htm
The sensitivity 25 years ago was amazing I can only imagine what it is today.