Real-world cracks don’t often resemble the idealized cracks on which fracture mechanics solutions are based. This is when categorization rules come into play.

This final installment of a 3-part series on SCC mitigation will provide practical, actionable steps to improve long-term equipment reliability through design, fabrication/welding, heat treatment, maintenance/repair, and process operating practices.

Part 2 of the three-part series on stress corrosion cracking (SCC) that examines common engineering and FFS methods that can be leveraged to understand and evaluate the propensity for an existing form of SCC to lead to loss of containment.

This article provides an overview of some of the more common forms of stress corrosion cracking (SCC) with a focus on effective inspection methods for detecting these forms of cracking.

The first two parts of this series covered the basics of fracture mechanics and how the FAD is interpreted. This article touches on a few practical points regarding the application of fracture mechanics in a plant environment.

Are you truly prepared for your next Turnaround? Effective work processes are required to successfully plan, manage, review and supervise plant turnarounds. Inspection planning and work scope selection are critical aspects of any turnaround...

Every fitness-for-service (FFS) assessment must have a well-defined acceptance criterion. For many damage mechanisms, it’s the “remaining strength factor” (RSF). But for crack-like flaw assessment, it’s the Failure Assessment Diagram, or FAD.

Fracture mechanics is a branch of engineering that describes the behavior of cracks – how they grow and when they fracture. Fracture of cracks is particularly dangerous because it can happen without warning under normal operating conditions.

Welding imperfections vary in impact from being acceptable to requiring repair. It is important to ensure the quality of welds using NDT and to ensure the strength of the entire piping system with hydrotesting.

There is concern in the industry over recent findings of reduced toughness fittings and flanges at risk of brittle fracture. This article provides an overview; possible contributors; measures taken to address; and a proposed FFS approach to address...

HTHA of hydrogen-containing equipment can be prevented with appropriate material selection and fabrication, appropriate welding procedures, regular inspection of equipment using proven, effective technologies and equipment operated by qualified...

TEAM provides full inline, onsite and, shop valve repair services and maintenance programs for virtually all valve types, brands, sizes, materials, pressures, and operating conditions, including actuators and operators. Our valve repair solution...

The enormous decline in oil prices over the past 14 months has definitely slowed projects and changed the energy and production landscape. Despite this, refineries, petrochemical plants, and chemical facilities must continue to run safely,...

This post is based on an article from the September/October 2008 issue of Inspectioneering Journal by Richard Green at Accurate Metallurgical Services. You can find the original article here.

Inspectioneering recently had the privilege of speaking with Tom Wanzeck, Vice President of Integrity Services with Willbros Group, Inc. Tom spent more than 20 years managing assets on the owner-operator side before making the leap to the service...

In this article you will find the failure investigations of six 0.094 inch thick carbon steel vessels. These vessels were in service in natural gas well facilities; some functioned as dryers and were subjected to cyclic loads. Metallographic tests,...

Titanium (Ti) hydriding is another somewhat unusual metallurgical degradation phenomena that can result in brittle fracture. Unlike many other steel embrittlement phenomena, this one most often occurs in thin wall Ti tubes that have been selected...

Statistical techniques are meant to complement the work of SMEs and can provide deeper insights into the inspection data collected as part of a reliability program. Pinnacle has combined traditional methods, expertise, and Machine Learning to...

Metals will slowly deform under stress and higher temperatures by the mechanism known as creep. The amount of creep deformation that will be experienced is highly dependent upon the level of stress, level of temperature and material properties....

Aging phenolic resin reactors built in the 1960's were constructed of SA304 stainless steel, many of which were originally fabricated to ASME Section VIII standards were never registered as such nor with the National Board. Some of these reactors...

Polythionic Acid Stress Corrosion Cracking (PASCC) is an affliction of many refineries processing sulfur containing feedstocks, and since that is the norm these days, most refiners reduce their susceptibility to PASCC by selecting resistant alloys...

Hydrogen stress cracking occurs when corrosion from acids like wet hydrogen sulfide or hydrofluoric acid (HF) cause atomic hydrogen to penetrate hardened or higher strength steels and cause stress cracking.

Amine cracking is a form of stress corrosion cracking, which is related to alkaline and carbonate stress corrosion cracking. Amine cracking is often intertwined with wet H2S and carbonate cracking, as amines, carbonates and wet sulfides often exist...

Pinnacle's data-driven reliability framework ensures the right data is fueling the right intelligence, helping you make confident, strategic decisions.

Chloride cracking of austenitic stainless steels (300 series SS) is an off-shoot of CUI, and there’s nothing really magical about it. If you have insulated solid stainless steel equipment operating in the CUI temperature range you are likely to...

DMW cracking is another fabrication issue that can and does result in equipment failure. It usually occurs at the weld juncture where carbon steel or low alloy steels are welded to austenitic (300 series) stainless steels in high temperature...

Cracks along the toe of a weld are not uncommon during fabrication, and can occur for a wide variety of reasons involving the metallurgy and process control of the the same issues covered above on repair welds can apply to repair welds on...

There are a variety of forms of wet H2S cracking. In this short article I will focus on two of the most common forms: hydrogen induced cracking and stress-oriented hydrogen induced cracking (HIC/ SOHIC). HIC is often fairly innocuous (but not...

Carbonate cracking (CC) of carbon steel has seen an increase recently in frequency and severity in some refinery cat crackers, especially in fractionator and gas processing overheads. Some gas scrubbing units are also susceptible. CC is a form of...

Traditional pressure vessel inspections often require taking assets out of service. However, MISTRAS’ Non-Intrusive Inspection (NII) programs provide data as good or better than internal inspections, while assets remain in service. NII is...

Ammonia stress corrosion cracking (SCC) has been around a long time. Most everyone has experienced it from time to time. It's not uncommon in brass tubes in cooling water service that is contaminated with ammonia due to biological growths or other...

Chloride stress corrosion cracking (SCC) is about as well known as any SCC mechanism can be, so I won't dwell much on it here, but want to mention it for the sake of completeness and hopefully mention something that is not as commonly known about...

Few of us have not experienced or heard about vibration fatigue (cracking) failures, especially around pumps and compressors. Typically small branch connections, equalizer lines, vents and drains are susceptible, especially if they are screwed...

Hydrogen-induced cracking is a damage mechanism commonly observed in the petroleum refining industry [1, 2]. The damage appears as laminar cracks and blisters, which can link up in the through-wall direction to form stepwise cracking.

This is the first of a series of articles that outlines the 101 essential elements that need to be in place, and functioning well, to preserve and protect the reliability and integrity of pressure equipment (vessels, exchangers, furnaces, boilers,...

Petroleum coke production is an important source of revenue for many refineries. While coking units were initially constructed to deal with a waste product, these units are now of significant economic value.

A key to any piping evaluation program is to understand where problems can occur. Vibrating piping can propagate a crack relatively quickly. Have you ever installed gussets to stabilize a vibrating pipe situation only to find, shortly thereafter,...

Exposure of carbon steel equipment to wet H2S service environments can lead to various forms of attack, e.g. hydrogen blistering and hydrogen induced cracking (HIC), stress oriented hydrogen induced cracking (SOHIC) and sulfide stress cracking...