Pro-Active Fitness for Service of 19 Meter Diameter NGL Surge Sphere

2002 ◽  
Author(s):  
Michael P. Walsh
Keyword(s):  
Service Life ◽  
General Corrosion ◽  
Average Thickness ◽  
Comparison Study ◽  
Defect Tolerance ◽  
Section Viii ◽  
Division 2 ◽  
Spread Sheet ◽  
Reference Tool ◽  
Excel Spread Sheet

To minimize costly down time, pro-active in lieu of reactive FFS assessments offer distinct advantages since the acceptable/unacceptable defect geometries and limitations are determined prior to the actual inspection. General Corrosion, LTAs and pitting were detected in the lower accessible sections of this 2″ average thickness sphere designed to ASME Section VIII, Division 2. API-510 and API-579 Levels 1, 2 and 3 were utilized to evaluate the documented defects in a comparison study. The defect geometries were then extrapolated to unacceptable levels to be used as a go/no-go reference tool for the remainder of the sphere and future inspections. Excel spread sheet numerical calculations and FEA non-linear analyses are employed. A significant increase in service life and defect tolerance over API-510 is realized.

It's about Time! Introducing Students to the Concept of Billable Hours and Improving Their Excel Skills By Creating a Spreadsheet to Track Their Time

2015 ◽  
Vol 10 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Timothy C. Hinson ◽  
Lorraine S. Lee ◽  
David C. Hayes
Keyword(s):  
Public Accounting ◽  
Tracking Time ◽  
Spread Sheet ◽  
Excel Spread Sheet

ABSTRACT The concepts of billable hours and tracking time are a reality in public accounting. The purpose of this case is to educate students on the concept of billable hours and to improve the student's Excel skills through the development of a spreadsheet to track their time. Students were required to create the time-tracking Excel spread-sheet and to track all (personal and school-related) of their time for two weeks. Students were given pre/post tests and surveys and the results reflect that students significantly increased their performance in intermediate and advanced Excel skills, billable hours concepts and realize the difficulty in tracking time. Even though the students acknowledged the difficulty in tracking time, they did enjoy learning more about billable hours that they may encounter in their future professions.

Limit Pressures of Cylindrical and Spherical Shells

2000 ◽  
Vol 123 (3) ◽  
pp. 288-292 ◽  
Author(s):  
Arturs Kalnins ◽  
Dean P. Updike
Keyword(s):  
Geometric Parameter ◽  
Cylindrical Shells ◽  
Length Effect ◽  
Spherical Shells ◽  
Simply Supported ◽  
Limit Pressure ◽  
Section Viii ◽  
Division 2

Tresca limit pressures for long cylindrical shells and complete spherical shells subjected to arbitrary pressure, and several approximations to the exact limit pressures for limited pressure ranges, are derived. The results are compared with those in Section III-Subsection NB and in Section VIII-Division 2 of the ASME B&PV Code. It is found that in Section VIII-Division 2 the formulas agree with the derived limit pressures and their approximations, but that in Section III-Subsection NB the formula for spherical shells is different from the derived approximation to the limit pressure. The length effect on the limit pressure is investigated for cylindrical shells with simply supported ends. A geometric parameter that expresses the length effect is determined. A formula and its limit of validity are derived for an assessment of the length effect on the limit pressures.

scholarly journals Perceptions of Mothers and Community Members Regarding Breastfeeding in Public Spaces in Alexandra, Gauteng Province, South Africa

2020 ◽  
Vol 13 (1) ◽  
pp. 582-594
Author(s):  
Madimetja Nyaloko ◽  
Welma Lubbe ◽  
Karin Minnie
Keyword(s):  
Social Sciences ◽  
South Africa ◽  
Public Spaces ◽  
World Health ◽  
Community Members ◽  
Gauteng Province ◽  
Breastfeeding In Public ◽  
Detrimental Impact ◽  
Spread Sheet ◽  
Excel Spread Sheet

Background: Mothers experience significant barriers to breastfeed in public spaces, which could result in a detrimental impact on the World Health Organization’s recommendation of exclusive breastfeeding. Failure to support and accept breastfeeding in public spaces could lead to mixed feeding or even abandonment of breastfeeding. Objective: The current study aimed to identify the knowledge of breastfeeding benefits and perceptions about it among mothers and community members in Alexandra, Gauteng Province, South Africa. Methods: A quantitative, non-experimental descriptive study was deployed using two structured questionnaires, which were distributed among mothers (n=96) and community members (n=96). All 192 questionnaires were completed and returned, although two questionnaires of mothers could not be used due to incompleteness. An excel spread sheet and Statistical Package for Social Sciences version 25 was used to analyze the data. Results: The findings of the current study revealed a positive correlation between the knowledge level about breastfeeding benefits [infants (r=0.45, p≤0.000) and mothers (r=0.29, p≤0.000)] and perceptions in public spaces. Community members and mothers who were knowledgeable regarding breastfeeding benefits exhibited supportive attitudes towards breastfeeding in public spaces. Conclusion: Altogether, the majority of mothers (69%) were comfortable to breastfeed in public spaces, and community members (84%) were supportive. Limited knowledge of breastfeeding benefits was associated with unsupportive attitudes towards breastfeeding in public spaces. Health messages that target these factors are essential to encourage support and acceptance of breastfeeding in public spaces. This could be executed through public education via posters in public spaces and during community health outreaches.

Applicability of Design Rules for Openings in Shells, ASME B&PV Code, Section VIII, Division 2 - A Case Study

2021 ◽  
Author(s):  
Gurumurthy Kagita ◽  
Krishnakant V. Pudipeddi ◽  
Subramanyam V. R. Sripada
Keyword(s):  
Stress Analysis ◽  
Failure Modes ◽  
Element Analysis ◽  
Design Rules ◽  
Area Method ◽  
Replacement Method ◽  
Local Stresses ◽  
Pressure Area ◽  
Section Viii ◽  
Division 2

Abstract The Pressure-Area method is recently introduced in the ASME Boiler and Pressure Vessel (B&PV) Code, Section VIII, Division 2 to reduce the excessive conservatism of the traditional area-replacement method. The Pressure-Area method is based on ensuring that the resistive internal force provided by the material is greater than or equal to the reactive load from the applied internal pressure. A comparative study is undertaken to study the applicability of design rules for certain nozzles in shells using finite element analysis (FEA). From the results of linear elastic FEA, it is found that in some cases the local stresses at the nozzle to shell junctions exceed the allowable stress limits even though the code requirements of Pressure-Area method are met. It is also found that there is reduction in local stresses when the requirement of nozzle to shell thickness ratio is maintained as per EN 13445 Part 3. The study also suggests that the reinforcement of nozzles satisfy the requirements of elastic-plastic stress analysis procedures even though it fails to satisfy the requirements of elastic stress analysis procedures. However, the reinforcement should be chosen judiciously to reduce the local stresses at the nozzle to shell junction and to satisfy other governing failure modes such as fatigue.

Section VIII: Division 2–Alternative Rules

2020 ◽  
Author(s):  
David A. Osage ◽  
Clay D. Rodery ◽  
Thomas P. Pastor ◽  
Robert G. Brown ◽  
Philip A. Henry ◽  
...  
Keyword(s):  
Section Viii ◽  
Division 2

Design, Manufacture and Safety Aspects of Forged Vessels for High-Pressure Services

1980 ◽  
Vol 102 (1) ◽  
pp. 98-106 ◽  
Author(s):  
G. J. Mraz ◽  
E. G. Nisbett
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Low Alloy Steels ◽  
Nickel Chromium ◽  
Molybdenum Alloys ◽  
Tension Tests ◽  
Alloy Steels ◽  
Section Viii ◽  
Division 2

Steels at present included in Sections III and VIII of the ASME Boiler and Pressure Vessel Code severely limit its application for high-pressure design. An extension of the well-known AISI 4300 series low alloy steels has long been known as “Gun Steel.” These alloys, which are generally superior to AISI 4340, offer good harden-ability and toughness and have been widely used under proprietary names for pressure vessel application. The ASTM Specification A-723 was developed to cover these nickel-chromium-molybdenum alloys for pressure vessel use, and is being adopted by Section II of the ASME Boiler and Pressure Vessel Code for use in Section VIII, Division 2, and in Section III in Part NF for component supports. The rationale of the specification is discussed, and examples of the mechanical properties obtained from forgings manufactured to the specification are given. These include the results of both room and elevated temperature tension tests and Charpy V notch impact tests. New areas of applicability of the Code to forged vessels for high-pressure service using these materials are discussed. Problems of safety in operation of monobloc vessels are mentioned. Procedures for in-service inspection and determination of inspection intervals based on fracture mechanics are suggested.

Method B Fatigue Screening in ASME BPV Code, Section VIII, Division 2, Part 5

2019 ◽  
Author(s):  
Kenneth Kirkpatrick ◽  
Christopher R. Johnson ◽  
J. Adin Mann
Keyword(s):  
Fatigue Damage ◽  
Pressure Vessel ◽  
Fatigue Analysis ◽  
Damage Factor ◽  
Simple Method ◽  
Mechanical Loads ◽  
Penalty Factor ◽  
Section Viii ◽  
Cyclic Service ◽  
Division 2

Abstract ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division 2, Part 5 Method B fatigue screening is intended to be a quick and simple method that is sufficiently conservative to screen components in cyclic service thus not requiring detailed fatigue analysis. The method assesses pressure, thermal, and mechanical loads separately. The basis for each portion of the method is discussed along with an alternative bases for the assessments. Each assessment is reformulated as a fatigue damage factor and all variables are provided so that the intent of each equation is clearly identifiable. A penalty factor will be included in each equation rather than assuming one penalty for all designs, the reformulation creates penalty for non-fatigue resistant designs and reduces the penalty for fatigue resistant designs. Examples are given showing the potentially non-conservative results if a summed damage is not used.

A Study of the Conservatism in ASME BPVC Section VIII Division 2 Opening Design for External Pressure

2019 ◽  
Author(s):  
Barry Millet ◽  
Kaveh Ebrahimi ◽  
James Lu ◽  
Kenneth Kirkpatrick ◽  
Bryan Mosher
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
External Pressure ◽  
The Other ◽  
Finite Element Analyses ◽  
Division 1 ◽  
Section Viii ◽  
Allowable Compressive Stress ◽  
Division 2

Abstract In the ASME Boiler and Pressure Vessel Code, nozzle reinforcement rules for nozzles attached to shells under external pressure differ from the rules for internal pressure. ASME BPVC Section I, Section VIII Division 1 and Section VIII Division 2 (Pre-2007 Edition) reinforcement rules for external pressure are less stringent than those for internal pressure. The reinforcement rules for external pressure published since the 2007 Edition of ASME BPVC Section VIII Division 2 are more stringent than those for internal pressure. The previous rule only required reinforcement for external pressure to be one-half of the reinforcement required for internal pressure. In the current BPVC Code the required reinforcement is inversely proportional to the allowable compressive stress for the shell under external pressure. Therefore as the allowable drops, the required reinforcement increases. Understandably, the rules for external pressure differ in these two Divisions, but the amount of required reinforcement can be significantly larger. This paper will examine the possible conservatism in the current Division 2 rules as compared to the other Divisions of the BPVC Code and the EN 13445-3. The paper will review the background of each method and provide finite element analyses of several selected nozzles and geometries.

Proposal of New Upper Limit of Hydrostatic Test Pressure in KT-3 of ASME Section VIII Division 3

2018 ◽  
Author(s):  
Susumu Terada
Keyword(s):  
Test Results ◽  
Design Factor ◽  
Burst Test ◽  
Increase Wall Thickness ◽  
Upper Limit ◽  
General Yielding ◽  
Test Pressure ◽  
Section Viii ◽  
Division 2 ◽  
Design Pressure

The current upper limit of hydrostatic test pressure in KT-3 of ASME Sec. VIII Division 3 is determined by general yielding through the thickness obtained by Nadai’s equation with a design factor of 0.866 (= 1.732/2). On the other hand, the upper limit of hydrostatic test pressure in 4.1.6 of the ASME Sec. VIII Division 2 is determined by general yielding through the thickness with a design factor of 0.95. In cases where a ratio of hydrostatic test pressure to design pressure of 1.43 similar to PED (Pressure Equipment Directive) is requested, the upper limit of hydrostatic test pressure may be critical for vessel design when material with a ratio of yield strength to tensile strength less than 0.7 is used. In order to satisfy the requirements in KT-3, it is necessary to decrease design pressure or increase wall thickness. Therefore, it is proposed to change the design factor of intermediate strength materials to obtain the upper limit of hydrostatic test pressure. In this paper, a new design factor to obtain the upper limit of hydrostatic test pressure is proposed and the validity of this proposal was investigated by burst test results and elastic-plastic analysis.

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