Analysis of Likelihood of Failure for the Thinning of High Temperature Sulfide and Naphthenic Acid Corrosion through Risk Based Inspection using API-581

The likelihood of failure for the thinning of high temperature sulfide and naphthenic acid corrosion, which affect to a risk of facilities, was analyzed through the risk based inspection using API-581 BRD. We found that the corrosion rate was increased with increasing temperature and total acid number(TAN). And maximum value of the technical module subfactor(TMSF) was not varied with operating condition, but the TMSF was sensitively changed at the range of low temperature, low flow rate, and high TAN. Also, the TMSF was increased as an used year and inspection effectiveness increased, but it was increased as thickness, inspection number, and over design decreased.

API-581에 의한 위험기반검사에서 고온 황화물 및 나프텐산 부식의 두께감소에 의한 사고발생 가능성 해석