Inspectioneering
Inspectioneering Journal

Differentiating Original Equipment Defects From In-Service Damage

By Ricardo R. Valbuena at DNV Inc, and Lynne Kaley at Trinity Bridge LLC / Trinity Bridge Digital. This article appears in the July/August 1997 issue of Inspectioneering Journal

Damage of carbon steel pressure vessels due to various in-service damage mechanisms continues to be a serious concern in the refining and petrochemical industries. A survey conducted in 1990 by the NACE T-8-16 Work Group to determine the nature and extent of cracking problems in wet H2S refinery environments showed that there was insufficient information reported about the type of cracking found to correlate cracking incidence with cracking mechanisms. Most of the inspections for cracking reported were detected during internal inspection using Wet Fluorescent Magnetic Particle Testing (WFMPT). As a result, it was concluded that in addition to the service related cracks reported, a number of "cracks" detected were the result of original fabrication, repair or alteration of the pressure vessels.

The survey responses reported inspection results for almost 5,000 pressure vessels. Overall, cracking was reported in 26% of the inspected vessels. For these vessels with reported "cracks", little or no correlation was found between the incidence of cracking and the operating conditions (such as temperature), post weld heat treatment (PWHT), or extent of weld repairs. For example, throughout the range of operating temperatures, the incidence of cracking only varied between 23% and 37%. These inspection results are not consistent with more recent results reported in the refining industry.

This content is available to registered users and subscribers

Register today to unlock this article for free.

Create your free account and get access to:

  • Unlock one premium article of your choosing per month
  • Exclusive online content, videos, and downloads
  • Insightful and actionable webinars
GET STARTED
Interested in unlimited access? VIEW OUR SUBSCRIPTION OPTIONS

Current subscribers and registered users can log in now.


Comments and Discussion

There are no comments yet.

Add a Comment

Please log in or register to participate in comments and discussions.


Inspectioneering Journal

Explore over 20 years of articles written by our team of subject matter experts.

Company Directory

Find relevant products, services, and technologies.

Job Postings

Discover job opportunities that match your skillset.

Event Calendar

Find upcoming conferences, training sessions, online events, and more.

Industry News

Stay up-to-date with the latest inspection and asset integrity management news.

Blog

Read short articles and insights authored by industry experts.

Asset Intelligence Reports

Download brief primers on various asset integrity management topics.

Videos

Watch educational and informative videos directly related to your profession.