In many in-service issues involving pressure equipment, it is often the case that the thickness of a cylinder reveals significant variations in thickness around its cross section. This variation could represent loss of thickness due to corrosion or erosion, or could involve additions of thickness from repair activities. A common issue deals with determining the overall affect of such variations on the integrity of the vessel. This paper describes a spreadsheet tool employing common geometric properties such that these thickness variations may be simply reduced to an effective thickness of the cylinder cross section. This effective thickness may then be used for purposes of conducting fitness for service assessments or to assist in the planning of repairs. The use of this tool is illustrated with two case studies.
ASME PCC-1 “Guidelines for Pressure Boundary Bolted Joint Assembly” was first published in 2000 [1]. Since that time, there have been advances in bolted joint technology and industry practices that necessitated an update of the original document. The new revision of PCC-1 [2] is over twice the length of the original document and contains many new and updated guidelines. Significant additional detail has been added to the document in an effort to provide the broadest possible array of bolted joint assembly considerations to cover situations commonly encountered in industry, and thereby improve the overall safety and performance of bolted joints. This paper identifies some of the notable changes/additions that are included in the updated document.
This chapter covers alternative rules to the construction of pressure vessels under Section VIII, Division 2. The Section is made up of nine parts and the organization within each part is as follows: rules and requirements, nomenclature, tables, figures, normative annexes, and informative annexes. Part 1 contains general requirements addressing the following subjects: reference standards, units of measurement, tolerances, and technical inquiries. Part 2 consolidates the responsibilities and duties of the User, Manufacturer, and Authorized Inspector. It also contains general requirements for report forms and maintenance of records. Part 3 contains all requirements related to materials of construction and is organized in a similar fashion to Part AM of VIII-2. The coverage includes materials permitted for construction of vessel parts, and supplemental requirements for ferrous materials, Cr–Mo steels, Q and T steels with enhanced tensile properties, nonferrous metals, and boltings and castings. The requirements of Part 4 provide design rules for commonly used pressure vessel shapes under pressure loading and, within specified limits, rules or guidance for treatment of other loadings. Design requirements for the application of the design-by-analysis methodology in VIII-2 are described in Part 5. Detailed design procedures utilizing the results from a stress analysis are provided to evaluate components for plastic collapse, local failure, buckling, and cyclic loading. Part 6 consolidates the various fabrication requirements from old VIII-2 and VIII-1. Part 7 contains the requirements for examination during construction of pressure vessels. Part 7A covers the responsibilities and duties for inspection and examination during construction of pressure vessels. Part 8, which contains the rules pertaining to the pressure testing of the vessel following completion of fabrication, describes requirements for hydrostatic testing and pneumatic testing. The requirements for overpressure protection of vessels built in accordance with this VIII-2 are provided in Part 9.
The purpose of this paper is to outline the final approved requirements for assembler qualification that will be published in ASME PCC-1-2013 Appendix A. A brief overview of the requirements and a more detailed look at the intended method of implementation of the requirements by industry are examined. In addition, a series of more general updates and corrections were made to the body of PCC-1, which will be included in the 2013 version. These changes are also briefly outlined within this paper, for the information of the user of ASME PCC-1.
In its 2016 Edition, ASME B31.3 [1] removed its long held provision for thread engagement that deemed the lack of complete engagement acceptable if the lack of engagement is not more than one thread. This change can have implications on existing piping assemblies which prompted some clarifications in ASME PCC-1 [2]. This paper reviews some of the reasons for the change, the issues around determining a specific measurable criterion of an acceptable amount of thread engagement, and proposes alternate criteria for the new construction codes to consider that are easily measurable and enforceable.
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