Pressure Vessel
Research Council
The Pressure Vessel Research Council
of the Welding Research Council,
Inc.
Chairman
Guido G. Karcher
Consulting Engineer
共Retired: EXXON Research & Engineering Co.兲
关S0094-9930共00兲02101-6兴
The Pressure Vessel Research Council 共PVRC兲 was formed in
1945 by the Welding Research Council to encourage, promote,
and conduct research in the field of pressure vessels and related
pressure equipment technologies, including evaluation of materials, design, fabrication, inspection, and testing. Several new dimensions are emerging in PVRC activities, including joint activities with other organizations, increased stewardship for
sponsoring organizations, and new ventures in the areas of continued operation of equipment. These and the numerous ongoing
technical projects are the challenges that face PVRC as we enter
the new millennium.
A major change in PVRC leadership occurred in July 1998
when Greg Hollinger joined PVRC as the new Executive Director.
Greg is no stranger to us at PVRC as he has been involved in the
design of pressure equipment for over 20 years in industry and
with PVRC for over 12 years, during which he served as Chairman of the Design Division and Vice Chairman of PVRC. Greg
notes that one of the most significant words in PVRC is ‘‘leverage.’’ In this regard, PVRC’s methods of conducting research
provide high economic leverage and technical management advantages for members and sponsors who participate in the R&D
projects.
PVRC partnering with the Japanese Pressure Vessel Research
Council has been a part of our business since the inception of
JPVC over 20 years ago. A similar joint partnership is being
forged with the recently formed European Pressure Equipment
Research Council 共EPERC兲 to address areas of research and development that are of common interest. We are maintaining a
close liaison with both EPERC and JPVRC via recent attendance
at the EPERC General Assemblies and JPVRC anniversary meetings. In addition to these meeting interchanges, we are constantly
exploring potential areas of R&D for joint ventures. Some examples of such activities are the potential joint EPERC/JPVRC/
PVRC projects on flanges and gaskets, fatigue testing of thin-wall
expansion joints, comparative reviews of the ASME Code and the
110 Õ Vol. 122, FEBRUARY 2000
European Pressure Equipment Directive 共PED兲, and the JPVRC/
PVRC program on simplified methods for nonlinear elevated temperature analysis. There are many other areas of common interests
that will continue to be explored in our future activities.
PVRC financial contributions come from membership and contributing interests, such as fabricators and users, material suppliers, research laboratories, insurance companies, code writing bodies, trade associations, government bodies, and others. In this age
of cost cutting and downsizing, PVRC has been called on to provide more detailed project stewardship and accountability than in
the past. As a result of this, a new publication, ‘‘PVRC Active
Project Descriptions and Status,’’ has been developed by our new
Executive Director Greg Hollinger as a way of summarizing the
status of over 125 projects that are presently being coordinated by
PVRC. This has now turned into an evergreen activity in our
attempts to provide improved project accountability and status on
the various projects.
The Continued Operation of Equipment 共COE兲 Division was
initiated in 1997 in response to industry needs in the area of evaluating the integrity and remaining life of aging equipment in process plants. The pressure equipment items being addressed range
in age from initial operation to over 50 years old. Projects such as
‘‘Technologies for the Evaluation of Crack Like Flaws’’ and
‘‘Technologies for the Evaluation of Erosion/Corrosion, Pitting,
Blisters, Shell Out-of-Roundness, Weld Misalignment, Bulges
and Dents in Pressurized Components,’’ ‘‘Design Margins for Inservice Equipment,’’ and ‘‘Local Thin Areas at Nozzles’’ are well
underway. The objectives of these activities is to provide design
and evaluation rules that can be referenced or incorporated in
existing codes that address post-construction requirements. In addition to the COE Division activities, the PVRC Design Division
and Materials and Fabrication Division and related committees
maintain and update long-range plans for their respective research
areas. These periodic updates are published in the attached
Division/Committee reports and three times a year in PVRC
‘‘Progress Reports.’’ The following are a few brief highlights of
projects being established that may be of particular interest to the
members.
• The ASME Special Working Group on Flange Joints is
implementing PVRC’s new gasket constants along with other
changes to the flange design rules. In connection with this, a joint
project is being established with EPERC in the areas of unifying
the methods of analysis and testing for bolted flanges and
gasketing.
• The ASME Code Case 2211 on ‘‘Pressure Vessels with
Overpressure Protection by System Design’’ has initiated a
project to study the methods and criteria needed to more uniformly apply and control the application of this critical code case.
• A project addressing a comprehensive rewrite of Section
VIII, Division 2 has been initiated. It is envisioned that this re-
Copyright © 2000 by ASME
Transactions of the ASME
Downloaded From: http://pressurevesseltech.asmedigitalcollection.asme.org/ on 01/27/2016 Terms of Use: http://www.asme.org/about-asme/terms-of-use
write will result in a complete update and modernization of Section VIII, Division 2 providing for different levels of design 共i.e.,
Levels 1, 2, and 3兲 which would permit allowable stresses and
details as a function of design, testing and materials quality levels.
• The PVRC has been requested to initiate a ‘‘fast track’’
project to compare the Section VIII, Div. 1 Code with the European Pressure Equipment Directive 共PED兲. A major deliverable of
this effort will be a PED Guideline Document for ASME Certificate (Stamp) Holders. This will address in detail what an ASME
stamp holder must do to satisfy the PED for Section VIII, Div. 1
constructions. Participation of European experts is also planned.
• A project is also being established based on requests from the
Petroleum Offshore Industry to establish a new stress criteria for
evaluating the results of detailed finite element analysis 共FEA兲 on
components such as offshore platform tubular structures. Any
such criteria will be based on modern methods of FEA analysis
including and considering elastic-plastic, nonlinear, and strain
limit methods, and will be applicable to other types of structures
共e.g., pressure vessels, tanks, etc.兲.
• Projects addressing materials toughness requirements are underway, including use of the ASTM master curve, Charpy tup and
drop-weight testing, and micro-test specimen for fracture toughness determination. These are all focused on confirming that construction materials can provide adequate toughness to preclude
brittle fracture failures.
The preceding is only intended to be a brief executive summary
of PVRC activities. The reader is directed to the more detailed
descriptions in the specific Division/Committee reports, which
follow.
A major component of the research and development of PVRC
is reflected in the over 400 WRC Bulletins that have been published by PVRC since 1949. These Bulletins provide a permanent
reference of code criteria, research results, and industry developments. Many of the very early Bulletins are still referenced and
used in engineering activities today. A summary of some recently
published WRC Bulletin titles is provided at the end of this annual
report.
Reports on PVRC-sponsored work are also published in many
other technical publications, as well as being presented at a variety of worldwide technical conferences. A number of papers were,
for example, presented at the July 1998 ASME Pressure Vessel
and Piping Conference in San Diego, California.
The most important assets of PVRC are its members and the
contributing organizations. Much of the Council’s work is done
by volunteers from industry with special talents and interests in
pressure vessels, piping, tankage, and related technologies. It is
the dedicated participation of these individuals from all over the
world and the PVRC staff that makes it a successful organization.
The industries and PVRC will face many new challenges in the
next few years. In this regard, we need the continued support of
our technical expert members and the financial and technical support from the contributing organizations to respond to these challenges and to continue to coordinate research in an efficient manner. As an example of such dedication, it gave me great pleasure
to present the awards of Honorary Member to Dr. W. D. 共Dor兲
Doty and Mr. Everett C. 共Ev兲 Rodabaugh at the February 1998
PVRC meetings and to Dr. Spencer H. Bush at the February 1999
meetings.
Let me close with a theme of continued support for research in
the pressure vessel and related technical areas and the establishment of new technologies where required. I also hope that the
partnering with other worldwide organizations will provide for
even more enhanced project developments and elimination of duplication in the respective research areas. Let us continue to learn
from past experiences and apply modern engineering technology
to progress into the new millennium.
Journal of Pressure Vessel Technology
PVRC Task Group on Increased
Allowable Stresses
Chairman
Guido G. Karcher
Consulting Engineer
关S0094-9930共00兲02201-0兴
The Task Group on Increased Allowable Stresses was formed
in 1995 in response to ASME and industry interests in evaluating
the design margins that are used in establishing allowable stress
used in pressure vessel design. Improvements or enhancements in
ASME Code rules over the last 40–50 years, successful experience with vessels designed to such code rules, improved materials
and fabrication practices, more sophisticated design rules, and
toughness requirements prompted the initiation of several PVRC
review-type studies in these areas. In addition the Task Group is
addressing PVRC projects related to the European Pressure
Equipment Directive and design margins for in-service
equipment.
ASME Section VIII, Division 1, Phase 1. The PVRC sponsored a two-phase project to evaluate and provide justification for
reduction of the design margin for ASME Section VIII, Division 1
from 4.0 to 3.5 on specified minimum tensile strength at temperatures below the creep range. The phase 1 project resulted in the
May 1996 publication of a PVRC report titled ‘‘Evaluation of
Design Margins for ASME Code Section VIII, Division 1’’ by
investigators Elmar Upitis and Kam Mokhtarian. This report was
submitted to ASME, and it provided the technical basis for the
recent ASME B&PV Code committee actions to issue the 1998
code cases 2278, 2284, and 2290, which provide allowable
stresses for Section I and Section VIII, Division 1 materials based
on a design margin of 3.5 on specified minimum tensile strength.
Even though Section I was not within the original scope of the
PVRC project, the ASME committee carried out separate review
and because of the close alignment of Section I and Section VIII,
Div. 1 also justified acceptance of the 3.5 margin for Section I.
Section III carried out a similar review and accepted the 3.5 allowable stresses for Class 2 and 3 constructions. All these revisions resulted in a major effort in ASME and The Materials Properties Council to update the allowable stress tables and
incorporate the 3.5 margin for all code materials in the Section II,
Part D, Tables 1A and 1B. This is scheduled to be issued as a part
of the July 1999 addenda to the Code.
ASME Section VIII, Divisions 1 and 2, Phase 2. In parallel
with the Phase 1 project, a more comprehensive Phase 2 project
was also initiated. The objectives of the Phase 2 project were a
more comprehensive study of the basic elements that need to be
considered when establishing a design margin and a detailed review of European codes. The results and conclusions of this
project are applicable to all pressure equipment standards even
though it focused on Section VIII, Div. 2 requirements. The Phase
2 project resulted in the November 1997 publication of a PVRC
report titled ‘‘Evaluation of Design Margins for ASME Code Section VIII, Divisions 1 and 2, Phase 2 Studies’’ by investigators
Elmar Upitis and Kam Mokhtarian. The B&PV Committee has
reviewed that work and that initiated the formation of an ASME
Special Task Group on the Restructuring of Section VIII, Div. 2.
As a result, PVRC has been requested to initiate a fast track
project to provide the technical basis needed to update and modernize Section VIII, Div. 2.
Update and Restructure of ASME Section VIII, Division 2.
Acting on the ASME request, PVRC formed a group of investiFEBRUARY 2000, Vol. 122 Õ 111
Downloaded From: http://pressurevesseltech.asmedigitalcollection.asme.org/ on 01/27/2016 Terms of Use: http://www.asme.org/about-asme/terms-of-use
gators to develop the technical basis needed to update and modernize Section VIII, Div. 2. The following highlights some of the
technological step-outs being considered:
• user-friendly and computer-compatible organization;
• vessel classification levels as a function of material and construction quality;
• modern stress evaluation criteria and recognition of advanced
analytical methods;
• modern NDE methods and acceptance criteria;
• yield and tensile properties and design factors in lieu of allowable stress tables;
• guaranteed material properties for use in design;
• toughness requirements as a function of design stress levels.
This project has been initiated and a white paper outline has been
prepared to establish industry technical and financial support.
Pressure Equipment Directive Guide for ASME Section
VIII, Division 1 Stamp Holders. All pressure equipment sold
or placed into service in the European Common Market countries
after May 29, 2002 will be required to carry a CE marking, indicating compliance with the European Pressure Equipment Directive 共PED兲, regardless where the vessel has been fabricated. Considering this, the ASME initiated a project to define what elements
of the ASME Section VIII, Div. 1 code do not satisfy the PED and
an outline of what Code revisions are needed to satisfy the PED.
The final objective is to publish a PVRC report that will serve as
a Guide for ASME Stamp Holders for Section VIII, Div. 1 Vessels. Both European and USA investigators are involved and the
project is nearing completion. A Phase II project addressing Section VIII, Div. 2 vessel PED construction may also be initiated in
the future.
Evaluation of Margins for In-Service Pressure Equipment.
The purpose of this study is to provide recommendations for reduced in-service design margins in vessels without reducing the
overall structural integrity of the vessel. It is essentially a vessel
rerating procedure that addresses the specific service conditions,
operating history, original construction code, material properties,
and mechanical details of a specific vessel. This project is closely
coordinated with the ASME post-construction and PVRC continued operation of equipment activities and a draft report is being
reviewed.
PVRC Division on Continued
Operation of Equipment
• Petroleum industry 共API, MPC FFS Committee兲
• Chemical Industry 共MTI, CMA兲
• Pulp and Paper Industry 共TAPPI兲
• Fossil Fuel Electric Power Industry
• National Board of Boiler and Pressure Vessel Inspectors
Chairman
J. Robert Sims
Becht Engineering Company
关S0094-9930共00兲02301-5兴
The Division on Continued Operation has formed two committees to parallel the two current ASME and API Standards
Committees:
• Committee on Flaw Evaluation to support the ASME Subcommittee on Flaw Evaluation and API Committee on Fitness for Service.
• Committee on Inspection Planing to support the ASME Subcommittee on Inspection Planing and the API Committee on
Risk-Based Inspection.
The Committee on Inspection Planning has recently been merged
112 Õ Vol. 122, FEBRUARY 2000
into the Committee on Flaw Evaluation. A new Committee on
Repair will be established if requested by the new ASME PostConstruction Subcommittee on Repair.
The Committee on Flaw Evaluation has completed a project on
Technologies for the Evaluation of Cracklike Flaws 共WRC Bulletin 430兲. A project on Technologies for the Evaluation of Erosion/
Corrosion, Pitting, Blisters, Shell Out-of-Roundness, Weld Misalignment, Bulges and Dents in Pressurized Components 共PVRC
Project 96-40兲 is nearing completion. Both projects involved surveys of the available literature, interview with folks actually performing evaluations in the field, to determine the ‘‘practical stateof-the-art’’ as it is currently being practiced in a variety of
industries.
Recommendations for methodologies for rapid screening assessments that can be performed by inspectors in the field, as well
as more advanced assessment techniques are included. A project
on design margins for in-service equipment is also nearing
completion. Design margins 共factors of safety兲 that can be used
for flaw acceptance and rerates for in-service equipment are defined in a form that can be used in the field and in the new postconstruction codes.
Phase I of a project on evaluation of local thin areas 共LTAs兲
near nozzles is underway. Techniques for the evaluation of LTAs
remote from discontinuities have been extensively tested and will
be incorporated into the appropriate standards. However, when
cracks are blend ground at nozzle to shell intersections or at the
toe of reinforcing pad fillet welds, rapid screening techniques are
not available to evaluate the acceptability of the resulting LTA.
Phase I will produce a finite element mesh generator to allow
rapid modeling of a wide range of geometries. Phase II will be a
parametric study to develop appropriate guidelines.
A project to summarize the literature on strain limits as a function of hydrostatic stress is underway. This is Phase I of an effort
to define acceptance criteria for elastic-plastic finite element
analysis. The results will be applied to both new and post construction. Phase II will include experimental verification of the
criteria.
These programs have been supported by funding from API,
ASME, the MPC FFS Committee, and the National Board of
Boiler and Pressure Vessel Inspectors.
Methodologies for the evaluation of creep crack growth will be
studied in a project funded by companies in the fossil fuel power
industry. The results will provide guidance to the ASME Flaw
Evaluation Subcommittee in completing the creep crack growth
section of their document.
Funding for Phase II of the LTAs near-nozzles project and
other future projects will be solicited from the following
organizations:
The projects managed by the former Committee on Inspection
Planning have been merged into the Committee on Flaw
Evaluation.
Phase I of a project to document Risk Acceptance Criteria used
worldwide is underway. This project, which is funded by the
ASME Foundation, will define the criteria used by government
agencies in the US and in several other countries for the acceptance at risk. The risk based management approaches currently
being codified by API and ASME can define both the probability
and consequence of failure 共i.e., risk兲. However, when the consequence of failure involves the health and safety of people or damage to the environment, the level of risk that is acceptable must be
determined through a political rather than a technical process.
This project will provide the background information needed to
initiate public discourse on this important topic.
Copyright © 2000 by ASME
Transactions of the ASME
Downloaded From: http://pressurevesseltech.asmedigitalcollection.asme.org/ on 01/27/2016 Terms of Use: http://www.asme.org/about-asme/terms-of-use
Other projects under consideration in the areas of nondestructive evaluation 共NDE兲 and risk-based inspection 共RBI兲 are expected to address:
• NDE ‘‘best practices,’’ including consideration of performance demonstration techniques for method and operator qualification, as well as automated techniques for ultrasonic examination
共UT兲;
• pilot and demonstration projects to validate risk-based inspection 共RBI兲 approaches;
• types of degradation and resulting failure frequencies of pressure equipment for use in inspection and maintenance planning.
• 关98-27兴 Design Margins for In-Service Equipment, E. Upitis,
Consultant.
Journal of Pressure Vessel Technology
• 关96-39, 96-38兴 Technologies for the Evaluation of Crack Like
Flaws, T. Anderson, SRT, published as WRC Bulletin 430.
• 关96-40兴 Technologies for the Evaluation of Local Thin Areas,
Blisters, Bulges and Geometric Discontinuities in Pressurized
Equipment, P. Krishnaswamy, Battelle.
• 关99-FE-01兴 Strain Limits as a Function of Hydrostatic Stress
• 关99-FE-02兴 Methodologies for the Evaluation of Creep
Cracks
• 关99-FE-04兴 Parametric Study of LTAs Near Nozzles
• 关98-25兴 Evaluation of Local Thin Areas Near Nozzles, T. L.
Anderson, SRT.
• 关99-IP-01兴 Documentation of Risk Acceptance Criteria Used
Worldwide, S. H. Bush and others.
Copyright © 2000 by ASME
FEBRUARY 2000, Vol. 122 Õ 113
Downloaded From: http://pressurevesseltech.asmedigitalcollection.asme.org/ on 01/27/2016 Terms of Use: http://www.asme.org/about-asme/terms-of-use