Anhydrous ammonia storage tank - internal inspection

[GregCanada]

We have recently replaced our anhydrous ammonia storage tanks. The originals began to suffer from stress corrosion cracking, ultimately blamed on the low water content of our product. (several hundred ppm of water passivates the steel preventing SCC). I can find no regulation defining the internal inspection frequency of these tanks, if any. Does anyone have any guidance?

 

[MJCronin]

These people recommend a risk based approach to determine tank inspection frequency.

http://www.leg.state.co.us/OSA/coau...FILE/2058 AnhydrousAmmoniaJuly2010 REPORT.pdf

MJCronin
Sr. Process Engineer

 

[SJones]

http://www.hse.gov.uk/research/rrpdf/rr760.pdf

M O Abdullah et al, Stress Corrosion Cracking, Crack Growth Prediction and Risk-Based Inspection Of Industrial Refrigerated Ammonia Tanks, Corrosion, Vol 67, (4), (online) pages 046001-1 - 046001-12

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[Latexman]

Following the most stringent standards, regulations, and Codes between the ones the tanks were built to and those associated with anhydrous ammonia seems like a good plan to me. I know the U.S. has a very comprehensive regulation on anhydrous ammonia tanks. Google it.

Good luck,
Latexman

Technically, the glass is always full - 1/2 air and 1/2 water.