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A REVIEW OF CURRENT SECTION VIII INITIATIVES

1. Proposed Revisions to Scope2. Common Rules Project3. Task Group U-2(g)

Thomas P. PastorChair ASME TOMCMember BPV-VIII

Proposed Revisions to Section VIII Scope

• Section VIII-1 scope rules are found in the Introduction• Scope has two meanings in the Code:

– What equipment was considered when the rules were developed• Makeup of the Committee is driven by the type of equipment the rules

are being written for

– Geometric Scope; • what is covered by the Code stamping

– E.g. vessel boundary ends at first circumferential joint to piping, or the face of the first flange connection to piping

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Basis for Scope and Applicability of Section VIII

U-1(c)(1) The scope of this Division has been established to identify thecomponents and parameters considered in formulating the rules given inthis Division. Laws or regulations issued by municipality, state,provincial, federal, or other enforcement or regulatory bodies havingjurisdiction at the location of an installation establish the mandatoryapplicability of the Code rules, in whole or in part, within theirjurisdiction. Those laws or regulations may require the use of thisDivision of the Code for vessels or components not considered to bewithin its Scope. These laws or regulations should be reviewed todetermine size or service limitations of the coverage which may bedifferent or more restrictive than those given here.

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Exemptions from Section VIIIU-1(c)(2) Based on the Committee’s consideration, the following classesof vessels are not included in the scope of this Division; however, anypressure vessel which meets all the applicable requirements of thisDivision may be stamped with the Certification Mark with the UDesignator.

(a) vessels within the Scope of other Sections;(b) fired process tubular heaters(c) pressure vessels integral with rotating machinery(d) piping systems(e) piping components(f) vessels containing water under pressure(g) hot water supply storage tank(h) vessels under 15 psi design pressure(i) vessels with ID less than 6 in.

• Exemptions in U-1(c)(2) began in 1940’s to restrict application of Codefor vessels where the product of volume and pressure exceed 60

– This was the original basis for the 6-inch rule and 15 psi limit

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Proposed Revisions to Section VIII Scope• BPV-VIII receives numerous inquiries on Stamping Scope

– Examples

• BPV-VIII issued a generic interpretation in 2008 that is now used to answer all future scope inquiries

• Current scope rules contain a listing of equipment and vessel limits that are not considered to be within the “jurisdiction of the Section of the Code”, even though the rules in the book adequately cover the construction of these items– Examples include:

• Vessels with inside diameter < 6”• Vessels intended for water service• Vessels with design pressure less the 15 psi

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Interpretation VIII-1-07-43

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Subject: U-1(c)(2)Date Issued: February 15, 2008File: 07-1263

Question: Paragraph U-1(c)(2) provides the definition of classes of vessels not considered to be within the scope of Section VIII, Division 1. Is it required to apply the ASME Code symbol [U or UM] to equipment that is not listed in the scope exemptions or only partially satisfies the provisions of U-1(c)(2) for a specific item?

Reply: See U-1(c)(1). The Code does not mandate the application of the ASME Code symbol for any piece of equipment. The laws or regulations issued by the municipality, state, provincial, federal, or other enforcement or regulatory bodies having jurisdiction at the location of an installation establish the mandatory applicability of the Code rules, in whole or in part, within their jurisdiction. Those laws or regulations may require the use of this Division of the Code for vessels or

components not considered to be within its Scope.

Proposed Revisions to Section VIII Scope

• Following the issuance of VIII-1-07-43, Section VIII appointed a Task Group on Scope to consider revisions to U-1(c)

• Task Group Scope Charter– Introduce pressure/volume relationship to replace current 6”

exemption rule– Determine if fluid(s) under pressure by the vessel should be

included within the pressure/volume relationship– Recommend revision to Conformity Assessment requirements to

mitigate risks associated with pressure/volume and contained fluid(s) to an acceptable level

– Make other revisions with goal to clearly state that responsibility for construction with Code Stamping lies with the jurisdiction , not ASME

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Proposed Revisions to Section VIII ScopeU-1(c)(2) Exemptions Removed

– U-1(c)(2)(f) – vessels containing water under pressure [ P<300 psi, T< 210°F]

• Exemption commonly used for water side of shell and tube H/X

– U-1(c)(2)(g) – hot water supply storage tank [heat input < 200,000 BTU/hr, T< 210°F, volume < 120 gallons]

– U-1(c)(2)(i) – vessels having and inside diameter, with, height, or cross-section diagonal not exceeding 6 inches, with no limitation on length of vessel or pressure

• This exemption is often used for small air receivers and high pressure accumulators

• With no limit on length or pressure, the stored energy can reach extremely high values, with severe consequences should there be a ductile rupture

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Proposed Revisions to Section VIII ScopeExemptions Added

• U-1(c)(3) – Vessels exclusively within the scope of other Sections of the ASME Boiler and Pressure Vessel Code are not included in the scope of this Division and shall not be stamped with the U Designator– This requirement currently exists in VIII-2

– Primarily concerned with construction of equipment that is covered by another ASME standard but the necessary expertise with this type of equipment is not contained within the current Section VIII committee membership.

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Proposed Revisions to Section VIII ScopeExemptions Added

• U-1(c)(4)(b) – vessels with a product of pressure times volume less than 90 psi-cu. ft (17 kPa-cu. meters) are outside the scope of this Division– Replaces the 6 inch rule

– Re-introduces a P x V = stored energy rule that was originally published in Section VIII in 1940

– This limit is independent of fluid or gas contained in vessel

– This limit is in the ballpark of the limit(s) used in the PED and Australian pressure vessel standard (AS 1228)

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What Size of Vessel & Pressure Is at the 90 Limit?

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Pressure (psi)

Volume (ft3)

Volume (Gal)

6” Diameter, L=? (in)

12” DiameterL=? (in)

24” DiameterL=? (in)

15 6.00 44.88 366.7 91.7 22.9

30 3.00 22.44 183.4 45.8 11.5

50 1.80 13.46 110.0 27.5 6.9

75 1.20 8.98 73.3 18.3 4.6

100 0.90 6.73 55.0 13.8 3.4

150 0.60 4.49 36.7 9.2 2.3

200 0.45 3.37 27.5 6.9 1.7

500 0.18 1.35 11.0 2.8 0.7

1000 0.09 0.67 5.5 1.4 0.3

2000 0.05 0.34 2.8 0.7 0.2

3000 0.03 0.22 1.8 0.4 0.1

Note: Calculation based on P*V = 90 psi-ft3

Vessels with a P*V < 90 do not require ASME Code Construction

Comparison of P*V=90 curves with PED

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Comparison of P*V=90 curves with Australian Rules

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Current Status of Proposal

• Proposed revisions have been approved by Task Group Scope

• Proposal currently being balloted to Subgroup General Requirements [confirm with Steve and Mark]

• Goal to ballot BPV-VIII and Conference Committee in November

• A review of pressure vessel laws for U.S. indicates that these proposed revisions will have minimum impact on most jurisdictions– Many jurisdictional rules repeat the exemptions currently

published in Section VIII; therefore a revision to the 2015 Edition will not affect current jurisdictional laws until either the laws are changed, or the 2015 Edition of Section VIII is adopted

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ASME B&PV Section VIIITask Group on Common RulesUpdate and path forward

Louis HaydenJune 12, 2013

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d1

Slide 16

d1 dosage, 1/19/2010

Presentation Overview• Scope

• Definitions – What are Common Rules?

• Objective of Common Rules Task Group

• Multiphase project

• Phase 1 – Multiple Tasks managed by PM

• Phase 2 – Start after Phase 1 is Completed

• Phase 3 – Start after Phase 2 is Completed

• Project Execution – Project Manager Required

• Status of Div 1 – Continue to Maintain Core Rules

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Scope

• Review and identify common rules contained in Section VIII Div 1, 2, 3

• Develop a plan to incorporate the recommendations of the Common Rules Task Group to reduce the workload on Volunteers to maintain the common rules in Section VIII Div 1, 2, 3

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Definitions

• Common Rules – those rules in Section VIII, Div 1, 2, and 3 that are identical and difficult to maintain because of:– complexity (i.e. either computationally or editorially

complex), and/or

– frequent updating because of the introduction of new technologies.

• Common rules typically occur in the design-by-rule or design-by-analysis parts of the code; but also exist in material, fabrication, and examination requirements

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Objective

• Common rules in the Section VIII Div 1, 2, and 3 codes should be identical and updated at the same time on the same ballot to ensure consistency

• Identify common rules that should be published in a single document and referenced by other documents to minimize volunteer maintenance time thereby reducing time to incorporate new technologies to keep the Section VIII codes competitive and to facilitate publication

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Objective

• Maintain core rules for basic vessel design such as wall thickness for shells and formed heads, nozzle design, etc. in Div 1; although different from Div 2 these rules are time proven and should remain in Div 1 because they provide sufficient design requirements for many vessels

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Phase 1

• Phase 1 is made up of five Tasks– Task 1: Development of a Code Case and modifications

to Div 1 UG-16 to permit Div 2 DBR to be used for Div 1 construction, and the evaluation of a similar action for Div 3 Completed CC2695

– Task 2: Modification of Div 2 to include vessel classes

– Task 3: Development of example problem manuals for Div 1 and Div 3 Div. 1 complete, Div.3 complete

– Task 4: Identification of common Rules in Div 1 and Div 3 that can be referenced from Div 2 Complete

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Phase 1

• Task 5 – Work with BCA to develop a plan for allowing current Section VIII, Div. 1 certificate holders to construct Section VIII, Div. 2 Class 1 vessels under their current authorization. Goal to have in place for use with 2015 Edition of Section VIII, Div.2

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• Add “Vessel Classes” to Div 2; most of the BPV VIII Committee work will be in Parts 1, 2 and 7

– Class 1: Design factor 3.5– Class 2: Design factor 2.4

• This will entice users to use Div 2 ;

LONG TERM GOAL IS TO HAVE CUSTOM ENGINEERED

VESSELS CONSTRUCTED TO VIII-2, EITHER AS CLASS 1 OR 2

– Div 2, Class 1 will have the same design margin and allowable stresses as Div 1

– Div 2, Class 2 will be essentially the same as current Div. 2• Concept of vessel classes was originally recommended by the PVRC and

ASME VIII-2 Re-write Steering Committees

Phase 1 – Task 2

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• Creation of a Div 1 example problem manual, recommend that this be done as an ASME LLC Project. Completed– Example problems should be worked out using VIII-1 and VIII-2 Part 4

alternative rules to clearly highlight advantages when using Part 4 rules• Article should be written in Mechanical Engineering Magazine

describing the common activity and the long-term goals. In Process

• Enhancement of Div 2 example problem manual will be required; example problems exist in UHX, Appendices 13, 14, and 24, and ultimately Appendices 2 and 26. Completed

• Creation of a Div 3 example problem manual, recommend that this be done as an ASME LLC Project. Complete

Phase 1 – Task 3

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Phase 1 – Task 4

• Identify common rules in Div 1; candidate common rules for Phase 1 are also shown on the next slide

• Make final decision on common rules ON HOLD– Delete from Div 1; include the paragraph (section or

appendix as required), and any associated figures, tables, and example problems

– Resolve cross-reference issues within Div 1.

– Make any required changes to Div 2 to facilitate cross reference from Div 1.

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Phase 2

• Evaluate feedback from customers on Phase 1 changes– Evaluate the affect of Phase 1 of common rules – Consider customer feedback and be careful!

• The workload and schedule for Phase 2 cannot be established until Phase 1 is complete

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Phase 2 • Continue to review common rules in Div 1 and 3

– Keep core rules for basic vessel design such as wall thickness for shells and formed heads, nozzle design, etc. in Div 1; although different from Div 2 these rules are time proven and should remain in Div 1 because they provide sufficient design requirements for many vessels

– Review rules for consistency even when it is decided to keep common rules in all three divisions to facilitate usability of the code

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Status of Div 1• Although discussed during previous meetings by the

Task Group, a decision to develop a simple pressure vessel code, Div 1, does need to be made at this time. It is the opinion of the PM that Div.1 needs to survive this process and be available to the users who need a simple vessel code.

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PROPOSE REVISIONS TO U-2(g)

TO ADDRESS DESIGN ISSUES

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U-2(g)

This Division of Section VIII does not contain rules to coverall details of design and construction. Where completedetails are not given, it is intended that the Manufacturer,subject to the acceptance of the Inspector, shall providedetails of design and construction which will be as safe asthose provided by the rules of this Division.

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Problems with U-2(g)

• Intended for providing design calculations for vessels or components for which rules do not exist in VIII-1– Because the word construction is used in the first sentence, some

certificate holders incorrectly use U-2(g) to justify use of non-code material, or a weld procedure that does not comply with Section IX

– Finite element analysis (FEA) is commonly used to satisfy U-2(g), however no meaningful check of FEA calculations is performed by AI’s

– There are many common load conditions ( e.g. wind, seismic, external loads on nozzles, horizontal vessels on saddles ) that fall under U-2(g); results in large variability in the different solutions

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Possible Solutions

• Codify design rules for certain loading conditions, thereby eliminating the need to invoke U-2(g)

• If the design rule exists in VIII-2 but not VIII-1, require use of the VIII-2 rule– Logic is use of any Code rule is better than no rule!

• Require RPE or some other 3rd party check when FEA is used

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Other Considerations

• Much debate on Manufacturer’s and Inspector’s responsibility for design calculations

• Manufacturer’s responsibility for calculations– Consensus is that emphasis should be placed on Manufacturer’s

responsibility• Proposed rules for defining minimum designer competence levels and

qualification requirements for personnel performing design work

• Proposed rules for when calculations should be checked by 3rd party, such as an RPE

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Other Considerations

• Consensus is that AI’s responsibility is to verify that applicable calculations exist and to spot check the calculations; not responsible for full QA check of calcs.

• Current proposal to U-2(e)

The term "applicable calculations" means that all pressure retainingcomponents covered by the Code stamping are supported by calculationsthat comply with the requirements of this Division. The method ofverifying that applicable calculations have been made will vary with theindividual Inspector and depend largely on the Manufacturer’sprocedures for producing the design calculations and any subsequentquality checks performed by the Manufacturer. Any questions concerningthe calculations raised by the Inspector must be resolved.

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