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Mr. Seipp has over 18 years of experience in design and analysis of process and power equipment, vessels, piping, and structures. He has extensive analytical experience including linear and non-linear finite element analysis using ANSYS and ABAQUS, buckling analyses, steady-state and transient heat transfer and thermal stress analysis of pressure v...essels and piping, fitness-for-service evaluations, and fatigue assessments. Mr. Seipp has worked for clients all around the world, who are in many different industries such as oil sands, refining, chemicals, mining, metals processing, pressure vessel and piping fabrication, and aerospace. Mr. Seipp is an author/co-author of over 30 journal and conference papers and presentations.  He is also a current member of Working Group - Design By Analysis (VIII). More

Basics of Design By Analysis in ASME Section VIII, Division 2

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How hard can it be?  I’ve heard from several (unnamed) analysts that because they have access to an FEA program and have successfully applied FEA in other fields, that FEA for pressure vessels should be a snap.  What is it about FEA for pressure vessels that makes it unique? I was recently discussing with another blogger regarding some distinctive aspects of performing Design By Analysis for pressure vessels.  We generated several questions, and so I decided to post this in a Question & Answer format. When do I have to use FEA in my pressure vessel design? The short answer here is that for most situations, you probably should not be using FEA to design your pressure vessel.  The rules for designing pressure vessels in ASME Section VIII, Division 1 and ASME Section VIII, Division 2 have a long history of successful application.  So, wherever possible, I would recommend that...
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ASME Section VIII, Division 2 Elastic Analysis Discussion: Collapse vs Ratcheting

ASME Section VIII, Division 2 Elastic Analysis Discussion: Collapse vs Ratcheting
  So, you think you know what load case combinations to use for your ASME Section VIII, Division 2, Part 5 analysis to satisfy Protection Against? Common sense says to follow to Code rules in Table 5.3 – but do you fully understand what that means? And, what loads should you use to satisfy Protection Against Failure From Cyclic Loading: Ratcheting? Are the same as for Plastic Collapse, or are they different? Over the past couple of weeks, I have had one particular issue come up several times with respect to elastic analysis to Part 5. There seems to be widespread misunderstanding about how to apply load cases to Protection Against Plastic Collapse and Protection Against Failure from Cyclic Loading – Ratcheting. So, I wanted to write this post to (hopefully) clear up some of this misunderstanding. Article 5.2, Protection Against Plastic Collapse, describes what design load cases and design...
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Trevor Seipp

RE:ratcheting vs cycling

Ratcheting is a different failure mode from fatigue; which is why each failure mode is handled separately in Part 5. You raise a ... Read More
Tuesday, 12 January 2016 12:41
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Performing an FEA in Section VIII, Division 1 to Qualify an Article U-2(g) Component

  While there are currently no explicit rules on how to perform a finite element analysis (FEA) if you are doing so in support of an ASME Section VIII, Division 1 vessel, there is good practice. Regarding rules, all you have is from Article U-2(g), which says: This Division of Section VIII does not contain rules to cover all details of design and construction. Where complete details are not given, it is intended that the Manufacturer, subject to the acceptance of the Inspector, shall provide details of design and construction which will be as safe as those provided by the rules of this Division. So, how exactly does an engineer perform an FEA, for which Section VIII, Division 1 has absolutely no rules, that is “as safe as” the rules otherwise provided in Section VIII, Division 1? Luckily, I’m not the first person to think about this. In fact, there...
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Mark Warner, PE

Thank you

Thank you for this review. I have used this approach for conformable pressure vessels where you need FEA to address the abnormal g... Read More
Friday, 13 September 2013 01:57
Trevor Seipp

Re: Thanks for guidelines

Shino Ulahannan - thank you for your questions. "1. What does ASME say about allowable deformations for a pressure vessel or vacu... Read More
Saturday, 07 December 2013 01:04
Trevor Seipp

Deformation values

"can we take the % strain or corresponding deformation against allowable stress(S - as defined by part D) from the stress strain p... Read More
Monday, 09 December 2013 18:01
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Submitting an FEA Report to ABSA

  The pressure vessel and piping jurisdiction in Alberta, Canada is ABSA – the pressure equipment safety authority. All pressure equipment as defined by the provincial Safety Codes Act must be registered with ABSA. I have been involved in registering piping systems and pressure vessels in this, my home jurisdiction. The focus of this blog post is what is required when you use an FEA to assist in the justification of your design. Based on my experience, ABSA’s preference is to have designs justified using Design-By-Rules. Therefore, in piping or pressure vessels, if there are rules in one of ASME Section VIII, Divisions 1 or 2 or ASME B31.3, then that is their preference. However, there are many situations where the specific geometry or loads are not explicitly covered by the rules. This may require a Design-By-Analysis. Note that these rules also apply to Fitness-For-Service FEA reports. Although there may...
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Trevor Seipp

Updated links

It has been brought to my attention that the link to the AB-520 has changed. The new link is http://www.absa.ca/wp-content/upload... Read More
Tuesday, 02 August 2016 12:02
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