TWI Industrial Member Report Summary 707/2000
By: A T Smith
PD6493 (1991) provides guidance for the assessment for fracture and fatigue of flawed welded and non welded structures. This code has gained widespread acceptance within industry. Corrosion defects can be assessed by assuming the defect is analogous to a planar defect. However, this assumption will often result in unnecessarily conservative estimates of the fitness-for-purpose of the corroded structure and requires additional information not strictly relevant to the assessment of corrosion damage. There is a need to review existing procedures, in order to develop a more realistic model for the assessment of corroded pressurised components.
Corrosion in pressurised components is an area of considerable economic importance and a number of procedures exist for the assessment for fitness-for-service of corroded pipes in particular. Because of their considerable economic importance and the volume of literature available, special attention has been paid to line pipe.
The aim of this review is to review published procedures for fitness-for-service assessment of corroded pressurised components.
This review describes existing methods for assessing the structural integrity of corroded components. The principal aim of this review is to see how currently available procedures can best be adapted for the consideration of corrosion in pressurised components. Specifically, the objectives are:
- to compare various candidate assessment procedures against commonly available burst test data.
- to recommend a procedure for the assessment of axially aligned corroded regions in pressure vessels and line pipes
- to provide a summary of simplified assessment strategies for corrosion in commonly available pressurised components.