SEDL / STP / STP1194-EB / STP24875S

Life Prediction of Ammonia Storage Tanks Based on Laboratory Stress Corrosion Crack Data

Nyborg, R
Senior Research Scientist and Department Head, Institutt for energiteknikk, Kjeller,

Lunde, L
Senior Research Scientist and Department Head, Institutt for energiteknikk, Kjeller,

Pages: 15    Published: Jan 1994

Download this paper for $25 PDF (252K)          View License Agreement
Abstract

Stress corrosion crack growth of carbon steel in anhydroi ammonia has been studied at both ambient temperature and at −33 %C. This has resulted in the development of a crack growth model where tl crack depth is predicted to be proportional to the square of the stress intensity factor and the square root of the exposure time. The crack growth is much slower at a low temperature of −33 %C than at ambient temperature. The crack growth model has been used together with field inspection results and probabilistic methods to obtain a quantitative measure for the probability of tank failure as function of time. This approach can be used by the ammonia storage tank operators to optimize the inspection intervals and procedures while assuring the safety of the tank.