A Parametric Three-Dimensional Finite Element Study of 45 Degree Lateral Connections, by P.P. Raju. January 1985 (33 pp) more detail...
1) An Analytical Comparison of Short Crack and Deep Crack CTOD Fracture Specimens of An A36 Steel; 2) The Effects of Crack Depth on Elastic-Plastic CTOD Fracture Toughness and 3) A Comparison of the J-Integral and CTOD Parameters for Short Crack Specimen Testing, by W.A. Sorem, R.H. Dodds, Jr. and S.T. Rolfe. February 1990 (34 pp) more detail...
Damage Mechanisms Affecting Fixed Equipment in the Pulp and Paper Industry, Jonathan D. Dobis and David C. Bennett, January 2004, 136 pages, ISBN: 1-58145-495-3 more detail...
Damage Mechanisms Affecting Fixed Equipment in the Refining Industry WRC Bulletin 489 -- February 2004 Jonathan D. Dobis, J.E. Cantwell, Martin Prager more detail...
Damage Mechanisms Affecting Fixed Equipment in the Fossil Electric Power Industry WRC Bulletin 490 -- March 2004 Jonathan D. Dobis and David N.French more detail...
Interpretive Report on Dynamic Analysis And Testing of Pressurized Components and Systems George Antaki, Jerry Bitner, Keshab Dwivedy, Henry Hwang, Rudy Scavuzzo May 2004 56 pages more detail...
Guidance on the Application of Code Case 2211?Overpressure Protection by Systems Design To protect pressure vessels from the potential for pressures in excess of values used in the design process, industries and ASME Code rules have traditionally used pressure relief devices. The device is installed at an effective location in the pressurized vessel system and is designed to open when the vessel pressure exceeds the relief pressure specified for the device. This overpressure design feature provides dependable protection for many vessels and systems. For vessels operating with hostile or corrosive fluids and environments, the pressure relief device may, over time, plug the inlet or outlet thereby causing the pressure relief device to be inoperative. To address this and other issues, alternatives to pressure relief devices were sought. Starting with Code Case 2211 in mid 1996 and Code Case 2211-1 three years later, ASME approved an acceptable alternative for Section VIII, Division 1 and 2 pressure vessels. This alternative to pressure relief devices uses the concept of overpressure protection by system design. In the implementation phase of the approved alternative, it was soon found that additional guidelines were needed to properly and more uniformly apply the technical requirements specified in the code case. In 1998, PVRC prepared a Request for Quote, evaluated potential investigators and initiated a development activity in mid 2000. The PVRC development activity culminated in this report, which provides detailed guidelines for owners, users and regulators in the implementation of Code Case 2211-1. More specifically, this report provides guidelines for conducting a detailed, organized, systematic, multidisciplinary analysis to ensure that the maximum allowable working pressure of the vessel is greater than the highest pressure that can reasonably be expected from all credible operating and upset conditions. Illustrative examples are included. These examples are typical of those employed in petroleum refining, chemical, pulp and paper industries and other similar process plants. more detail...
Most of the US design codes and standards for pressure containing equipment do not adequately address degradation and damage during operation. In the pressure vessel and pipeline industries, surface flaws are major limiting factors of vessel or pipe remaining life, and this type of degradation due to age and aggressive environment eventually threatens the structural integrity of equipment. Replacing vessel and piping equipment is expensive, making it cost effective and desirable to operate damaged pressurized equipment. For corrosion beyond a specified limit or other damage mechanism like cracking, a Fitness-For-Service (FFS) assessment is required. The specific objectives reported in the bulletin are: ? Objective 1 ? Validate the API 579 Section 5 LTA rules in addition to the validation in WRC 465. Significant validation work was reported in WRC 465. After publication, additional burst pressure results became available. The validation now includes comparison of the API 579 methodology to other industry methods and to a database of full scale test results. ? Objective 2 ? Develop new or improve upon the existing methodology to increase the accuracy of the assessment procedures and eliminate some of the limitations. There are twenty-five different methods compiled in this study for analyzing local thin areas in pipes and vessels. These analysis methods all have roots in various industries, codes, and standards. In industry, at least five of these methods are actively used in fitness-for-service assessments today. This can make communication difficult between parties using different assessment procedures, and some parties may be using methods with low accuracy or reliability. Depending on the assessment code that is used, assessment results may vary drastically. One standardized set of analysis guidelines is needed to eliminate confusion regarding which method should be used ? Objective 3 ? Standardize the in-service margin between MAWP and failure pressure for industry analysis methods and different construction code margins on allowable stress ?The LTA assessment methods in API 579 may be used to evaluate equipment built to many different construction codes. Because the design margins in these codes are different, a method needs to be introduced that permits scaling of LTA assessment results such that a consistent in-service margin can be obtained based on the ratio of predicted burst pressure to the maximum allowable working pressure computed using the appropriate procedures in each construction code. ? Objective 4 ? Improve the existing rules for LTAs subject to supplemental loading (circumferential extent of the LTA). Significant improvements have been made to the original method contained in API 579 published in 2000. ? Objective 5 ? Introduce assessment procedures for the evaluation of HIC damage. An assessment method based on a remaining strength factor has been developed for sub-surface and surface breaking HIC damage. ? Objective 6 ? Introduce procedures for the evaluation of local metal loss in cylindrical shells subject to external pressure. A simplified method has been developed to evaluate metal loss in cylindrical shells subject to external pressure using existing construction code rules for external pressure evaluation. more detail...
High Performance Cast ???-Strengthened nickel Based Superalloys ?V An Interpretive Report This bulletin reviews, evaluates, and summarizes the recent development and current knowledge of ???-strengthened nickel base cast superalloys. Since the publication of SuperalIoys II by Sims, Stoloff, and Hagel in 1987, there have been great advancements in the alloy development, manufacturing, coating, and repair of ???-strengthened nickel-base superalloys. Wider use of single crystal and directionally solidified superalloys in newer industrial turbines has prompted more effort in welding, repair, and properties assessment. The most representative for each aspect of this complex family of alloys is selected for study from the vast amount of literature, including those that are most widely used in today??s industry. The representative alloys under this category include IN738, GTD-111, PWA-1480, CMSX-4, and other newer single crystal superalloys. Special emphasis has been given to the metallurgy and properties evaluation of these superalloys. This bulletin serves as a supplement to SuperalIoys II by providing an update on this fascinating class of engineering alloys. Wrought nickel base superalloys which contain less amount of ???, cobalt base superalloys, ceramic materials, and intermetalics are not included. more detail...
Creep crack growth was introduced over 25 years ago as a fracture mechanics discipline. However, its application to engineering structures remains rare. With funding provided by the Edison Electric Institute (EEI), WRC?s Pressure Vessel Research Council (PVRC) initiated a program to facilitate implementation of creep crack growth methods in electric power plant maintenance strategies. The objective envisioned required incorporation of an accepted creep crack growth methodology in a post-construction flaw evaluation Codes. The goal has now been reached with the inclusion of methods in an API/ASME Fitness-for-Service Standard. An important element of the plan was to establish a network of internationally recognized investigators to work on the project and to use that group to report state of the art information as the basis for developing the proposed practice. The group provided a definitive evaluation of currently used major creep crack growth methods/parameters, identifying the strengths and weaknesses of each considering issues appropriate for use in the power plant applications to be covered. This WRC Bulletin covers the procedures evaluated by Prof. Kamran Nikbin and his colleagues at Imperial College in London. It is one of a set prepared to detail the methods, preserve the data used and comprehensively explain the concepts of the participants and others. The results of calculations of incremental growth are assembled on a FAD diagram. If a point on the FAD predicted for crack growth to a service time lies on or outside the FAD failure contour, then the life of the component is limited to the time corresponding to such service. If this time is less than the current operating time, the component should be repaired or retired. more detail...
