Direct Assessment is a structured process that is used to evaluate the integrity of pipelines subjected to external and internal corrosion and stress corrosion cracking. The successful application of direct assessment is predicated on establishing a reliable and defensible reassessment interval that depends on establishing the remaining life of un-repaired defects remaining in the pipe wall. An accurate assessment of corrosion growth rates is required to predict the remaining life of such defects. A wide variety of unqualified corrosion rates are offered in the literature that may not directly lend themselves to the application of direct assessment. Various techniques are discussed for establishing reliable corrosion growth rates and quantifying the effects of corrosion induced by stray electrical currents, microbial activity and differential aeration corrosion cells. The focus of this paper is External Corrosion Direct Assessment .

Subject
External corrosion direct assessment, Corrosion rate, Leaks, Pipelines, General corrosion rate, Corrosion growth, Mechanical failure, Defects, Anomalies, Wall thickness, Corrosion data, Linear polarization resistance, Soil
Keywords:
direct assessment, anomaly, defect, corrosion growth rates, linear polarization resistance (LPR), coupons
© 2006 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2006
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.