w ;:~7f? guidelines for piping system m[;% % j

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Topics: EPRI NP 5639

I Nuclear powar plants Project 01015Piping systems Final Report

Electric Power Construction May 1988Research institute Configurations

W ;:~7F? Guidelines for Piping SystemM[;% % j1 Reconciliation (NCIG-05,

Revision 1)

Prepared byReedy Associates, Inc.Los Gatos, California

910228017e 910222PDR PROJ PDR669A

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RE PORT SU MMARYSUBJECTS Quauty engineering / construction / Nuclear plant operations and

maa nance / Nuclear component reliabilitye- . - _ - . _ . - - - - - - . - - . _ - - -

TOPICS war power plants Cs uuction'

eng systems Configurations4

AUD1L M^ i Generation engineers and managers_ _ . ___ _ _ _ . _ _ _ . . .

Guidelines for Piping System Reconciliation(NCIG 05, Revision 1)

The nuclear pc .er industry has developed c itoria for reconcilingdifferences between the design of safety related piping systemsand the constructed configuration. These NRC accepted guide-lines represent the fifth in a series of EPRI-Nuclear Constructionissues Group (NCIG) cosponsored studies. They provido a cost-and time-effective cpproach for evaluating piping systems.

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BACKGROUND Piping installed at nuclear power plants can deviate from exact dimensionsgiven in design documents. NRC requires reconciliation of such deviationsin safety-related piping systems to ensur9 U.;t they have no significantoffect on plant safety and performance W.:,ing Resourch Council (WRC)

,Bulletin 916 describes critoria for reconciling differences devoleped by WRCin a pc' Technical Position on Piping Systems Installation Tolerances."Hower .: 'dustry lacked a consistent approach for implomonting bulletin316 (c16 ..

OBJECTIVE To develop guidelines to resolvo dideronces between designed and constructedcortigurations of safety-related pipin0 systems at nuclear power plants.

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APPROACH A working group of utility piping ongincors, architectiongincors, and consul-tants reviewed the WRC Bulletin 316 tolerances. Drawing on extensiveexperienco gained through the design, installation, and reconciliation ofmany piping systems, they developed guidelines for reconciling differencesbetwoon riesigned and installed piping systems. Their work focused on pip-ing dimensions, component weigria, support locations, and orientations.They submitted the consensus guidelines to NRC for acceptanco.

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RESULTS Those guidelines-in the form of a practical set of instructions-provido auniform approach for resolving differences betwoon designed and con-structed piping system configurations. The guidelines permit acceptance ofinstalled piping systems that are within the specified tolerancos withoutadditional analysis. They also provide recommendations for ovaluatingcases where the installed system excoods the specified tolerances and givesuggestions for documenting reconciliation activities. The report contains

EF*ll NP4 639s

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| soveral eumples that include illustrations to help users impismsnt 1

| the guidehnos, NRC has accepted these guidelines for performingreconciliations.-

EPRI PERSPECTIVE Reconciling the differences between designed and installed piping sys-tem configurations can be costly and time consuming. Previously, there*

was no industry consensus on tolerances, documentation of reconcilia-tion activities, or the level of detail required for the evaluation process.By providing industry and NRC accepted guidelines, this approach

'will help util.tles easily demonstrato the acceptability of original orretrofit piping installations and avoid costly analyses and hardware

,modihcations.

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PROJECT RPO1015EPRI Project Manager: Warren J. t... nin .

Nuclear Construction issuaa Grcup / Nuclear Power Division |Contractor: Reedy Associates. Inc. l

For further information on EPRI research programs, callEPRI Technical Information Specialists (415) 855 2411.

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Guidelines for Piping System Reconciliation,

(NCIG 05, Revision 1)__

NP 5633Research Project 01015

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final Report, May 1988

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|Prepared by 1

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REED ( ASSOCIATES. INC1

i 103 Albnght Way :

Los Gatos, Ca!itornia 95030

Pnncipal investigatorsR. W MikitkaR. F. Roody

NUCLEAR CONSTRUCTION ISSUES GROUPTask Group on Guidelines for Piping System Reconcikation ;

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Prepared for

Nuclear Construct.on issues Group .

and

Electnc Power Research Institute,

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3412 Hillview AvenuePalo Alto, California 94304.

EPRI Project ManagerW Bilanin

Nuclear Power Division

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; ORDERING INFC"MATION

Requests for copics of trus report thould to daccted to Resenrch Hoports Center(RRC) Box 50490. Palo Alto. CA 94301 (4tf>) 906408t On foquet:t. RRC will s.end acataloO of EPRI repo ts j

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ACKNOWLEDGM[NT

The following personnel participated in the development of this document:

M. Stephen Sills, Chairman Duke Power Company

Thomas [. Bostrom Bechtel Western Power Corporation

Marcus N. Bressler Tennessee Valley Authority

Artin Dermenjian Sargent & Lundy

Dan Van Duyne Stone & Webster Engineering

Sanat W. Korde [basco services, Inc.Joseph R. Pobre General [lectric Company

Walier H. Weber Union [lectric Company

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CONTENTS'

Section PaSeI

1 INTRODUCTION 1-1 1

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2- SCOPE- 2-1

3 DEFINITIONS 3. ' j

3.1 Nominal Dimension 31 |!3.2 As-Analyzed Configuration 31

3.3 Critical-to-Design (CTD) Dimension 3-1>

3.4 fit / Clearance (F/C) Dimension 3-1

3.5 Piping Drawings 3-2

3.6 As-Built Documents 3-2

3.7 Installation Tolerance 3-2

3.8 Total Tolerance 3-2

3.9 Piping Stress Analysis 3-2

3.10 Support 3-35

3.11 Anchor 3-3.

3.12 Designer 3-3 )3.13 Owner 3-3

3.14 installation 3-3

3.15 Reconciliation 3-3

4 PIP!NG DESIGN, INSTALLATION, INSPECTION, AND RECONCILIATION 41

4.1 General 4-1

4.2 CTD Dimensions and Tolerances 42

4.3 Installation Tolerances 4-2

4.4 Identify CTD Dimensions and Tolerances 4-3

4.5 Weights 4-3

4.6 fabrication 4-3

4.7 Inspection 4-4

4.8 Modifications 4-4

4.9 As-Built Documents 4-4

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4.10 Reconciliation 4-4

4.11 Final Walkdowns 4-4

5 MEASUREMENT ACCURACY 5-1

5.1 Angular Measurem^nt 5-2

5.2 Linear Measurement 5-2,

5.3 Elevations 5-2

5.4 Methods of Dimensioning 5-2 ,

5.5 Rounding Off 5-2J

6 TOLERANCE $ 6-1'

6.1 Total Tolerance 6-1

6.2 Altering Relative Position 6-1

6.3 Indepe Jence 6-1

6.4 Tolerance Categories 6-1

6.5 Piping Configuration Tolerances 6-2

6.5.1 Centerline Lengths 6-2 i

6.5.2 Centerline Location of Branch Connections 6-2,

6.5.3 Angular Deviation of H pe Centerline 6-4

6.5.4 Angular Tolerance on Power Operated Valves 6-4

6.6 Piping Support Location / Orientation Tolerances Q-4

6.6.1 Location of Supports 6-4

6.6.2 Location of the first Support on Either S Heof Spans that Contain Concentrated Weights 6-5

6.6.3 Location of the First Support from RotatingEquipment Nozzles C-5

6.6.4 Snubbers 6-5

6.6.5 Angular Orientation of Supports 6-5

6.7 Weight Tolerances 6-6

6.7.1_ uniformly Distributed Weight 6-6

6.7.2 Concentrated Weight 6-6i.

7 TOLERANCE JUST!f! CATION AND COMMENTAPY 7-1

7.1- Centerline Length of Pipe Elements 72

7.2 Branch locations 7-2

7.3 Angular Deviaticn of Pipe Centerline 7-2

| 7.4- Angular Tolerance on Power Operated Valves 7-2

7.5 Support Location 7-2L

7.6 Support Location Adjacent to Concentrated Weights 7-2

7.7 Angular Tolerance for Support Axis 7-3

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7.8 Uniformly Distributed Weight 7-3

7.9 Concentrated Weight 7-3

8 EVALVATION Of OUT-OF-TOLERANCE CONDITIONS 8-1

8.1 Evaluation using Engineering Judgment 8-2

B.2 Evaluation using Simple Structural Models 8-2

8.3 Evaluation by Peanalysis 8-?

8.4 Model Modification and As-Duilt Conditions 8-3

8.5 Oynamic Loading Considerations 8-3

9 !MPLEMENTATION SUMMARY 9-1

APPENDIX A EXAMPLES A-1

APPENDIX B NRC LETTER ACCEPTING GUIDEllHES FOR PIPING SY$ TEM B-1

RECONCILIATION (NCIG-05, REVl$10N 1)

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LIST OF FIGURES

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$-1 Illustration of Angular Dir.iensions.. Pipe legs. Valves. $-3Supports. Bends

- 5-2 111ustratton of Linear Dimensions 5-4,

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_ Table g5-1 Tyre of Measurement and Accuracy S-1

6-1 Cranch/Run Size Combinations 63 '

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EXECUTIVE SUMMARY

The Nuclear Regulatory Commission and the ASME Boiler and Pressure Vessel NuclearCode require a reconciliation of the as-built installation of piping systems withthe as-analyzed piping system. The need for a consistent approach by the industr,in performing these reconciliations led to the development of a position paperprepared by the fressure Vessel Research Committee (PVRC) and entitled " TechnicalPosition on Piping System Installation Tolerences." The paper, published as

Welding Research Council (WRC) Bulletin 316, provides recommendations f or per-forming piping system reconciliations and includes tolerances on piping configura-tion and locations of piping supports.

This document provides guidelines for implementing the PVRC Technical Position.Specific tolerances are provided for piping dimensierc,, component weights, andsupport locations and orientations. Piping systems that meet the specifiedtolerances are acceptable without need for further reconciliation or reanalysis.

When the specified tolerances are exceeded, the out-of-tolerance item must beevaluated by the Designer. Recommendations are provided for performing thesedesign evaluations.

The NRC staf f has reviewed this document and issued a f avorable review letter(Appendix B). The NRC concludes that this document represents a technicallyacceptable approach for performing reconciliations of er Sa-built installation ofpiping systems with the as-analyzed piping system.

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Section 1

INTRODUCi10N

Current regulations for the licensing of nuclear power plants require thatsignificant dif ferences between the as-analyzed and as-built configurations ofsafety-related piping systems be reconciled.

The Nuclear Regulatory Commission (NRC) and the American Society nf MechanicalEngineers (ASML) Boiler and Pressure Vessel Committee have recognized thatconstructed equipment and structures will deviate from the exact dimensions shown

in the design documents. These deviations are acceptable when they are within thespecified tolerances and when the Designer evaluates out-of-tolerance differences.The evaluations may be based on judicial application of documented engineeringjudgment.

The NRC issued Inspection and Enforcement (!E) Bulletin No. 79-14 (revised July18, 1979 with Supplement of August 15, 1979) which requires verification that theseismic analysis is consistent with the as-built configuration of safety-relatedpiping systems, with the exception of certain small bore piping systems. This

verification is intended to consider features of the system which have a

significant ef fect on the dynamic seismic analysis such as piping configuration,support type and location, embedments, pipe attachments, and weights of valves andvalve operators.

Significant discrepancies identified by piping system walkdowns are evaluated bythe Designer primarily for their effect on the validity of the stress analysis.

This evaluation may lead to decisions ranging from "use-as-is" to requiring aphysical modification to the system or reanalysis when the inspection showssignificant dif f erences f rom the arrangement used as a basis for the analysis.Such evaluations are separate from the design process and the significance ofbeing outside some design parameters or tolerances is a determination to be madel'y the Designer,

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Sectitn !!! of the ASME Boiler and Pressure Vessel Code contains reconciliationrequ'rements in NCA-3554 " Modification of Documents and Reconciliations withDes gn Report." NCA-3554 requires that significant dif ferences between the as-built piping system and the construction drawings must be reconciled with the

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Design Report.i

The implementation of 1[ Bulletin No. 79-14 and NCA-3554 has proven to be both'

costly and time consuming because, at present there is no agreement on what are- significant dif ferences or the tolerances to be applied, the definition of detail !

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required for as-built documentation, and the detail of analysis required for theIevaluation process. The approach provided in these Guidelines represents<

collective industry judgment and 15 based on good engineering practice. |

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Section 2

SCOPE

This document provides guidelines for implementing WRC Bulletin 316, TechnicalPosition on Piping System Installation Tolerances, prepared by the Pressure VesselResearch Committee (PVRC) Technical Committee on Piping Systems. WRC Bulletin 316

provides tolerances on the as-built geometry of piping and piping supports thatare considered acceptable for reconciliation with as-analyzed geometry along withcommentary and justification. As described in Section 7 these tolerances havebeen established such that their ef fect on the accuracy of analysis results is

minimal and is consistent with accepted practices and the use of tolerances in thedesign code. The Guidelines described in this document shall not be used inarbitrary f ashion for projects were tolerances have already been established whichare less than those given in these Guidelines. Consideration shall be given tosituations where any dimensions or weights may require smaller tolerances toassure that the intent of the bases or the design code have been satisfied. The

tolerances in the Guidelines are applicable to piping systems where conventionalseismic analysis methods were used for the criginal design, i.e. , modal responsespectrum analysis methods. For piping systems where seismic analysis methods thatare significantly more sensitive to the tolerances were used in the originaldesign (i.e., seismic time history analysis methods), the Designer shall reviewthe applicability of these tolerances and estabitsh more stringent guidelines ifnecessary. Further, this document should be restricted to piping systems analyzedusing linear elastic methods and qualified on the basis of currently accepted

design criteria as specified in any of the ASME codes or more conservative

standards.

The tolerances and portions of the commentary and justification f rom WRC Bulletin316 have been essentially repeated in this document so that this document will beself-sufficient.

This document prcvides guidance for use by the Owner or his designee in developingproject standards and procedures for inspection and reconciliation of: pipingconfigurationst pipe support locations and orientations; and component weights.

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| dimensions and in-line component weights that are outside the specified'

tolerances.

1 .Use of documented engineering judgment is an accepted means for reconciling out-

! of-tolerance items or for deciding when more elaborate analysis techniques arei_ required. Documented engineering judgment is also suggested when the particular

case examined does not fit within the range of parameters considered in thisGuideline.-;

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J The Owner may specify more restrictive tolerarces on installation than those )specified in this Guideline or may use less restrictive tolerances when !

engineering justification is provided to demonstrate that the design requirements

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have_ not been compromised. The Owner, with input from the Designer, shouldconsider specifying installation Tolerances smaller than the Total Tolerances asdiscussed in Section 4.3.

This Guideline document addresses tolerances for complete, installed pipingsystems. The Guideline document does not address tolerances to be provided for

manuf acturing or f abricating the individual items or subassemblies that make up4

piping systems. Other design and construc. ion areas which may be included inreconciliation such as design or operating conditions, support details and gapsare not addressed in this document.

Tolerances for support erection including length and orientation of individual '

members and pipe location on the support are not addressed in this document.

Examples of-implementing the Guidelines are provided in Appendix A.,

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Section 3,.

3

DEIINITIONS

Definitions of terms used in this Guideline document are as followst,

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3.1 Nominal Dimension |1

This is 'a dimension which provides configuration and/or spatial information onpiping drawings within specified tolerances.

3.2 As Analyzed Configurati_on1

This is the configuration of piping and supports, defined by nominal sizes,weights, crost-section properties and dimensions, which forms the basis for thepiping stress analy$is, in the case of piping systems which are qualified bysimplified rules, the design drawings for the systems are considered as the As.

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Analyzed Configuration.

3.3 Critical.to-Design (CTD)___ Dimension

. A dimension that must be satisfied, within a specified tolerance, in order for thepiping stress analysis to be consistent with the as-built configuration. These

dimensions define the relative configuration of the piping. They may also includedimensions which define the global or spatial position of the piping.-

Examples of CID dimensions are: the location of a pipe support relative to in.

line- pipe components such as valves, anchors, and other supports; the orientation

! of the pipe support centerline relative to -the pipe centerline; length of piperuns; and spacing between supports.

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-3.4 fit / Clearance (f/C) Dimension

This is a dimension that is specified to -provide reasonable assurance that _the

piping will fit into the allocated building space or to provide for clearancebetween the pipe and adjacent components . These dimensions define the globalposition _ of the piping in three dimensional space and deviations: from thesedimensions do not have a significant effect on the validity of the piping stress

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' analysis. Examples of f/C dimensions are the locating dimensions of pipe center-lines from column lines, walls, and floors.

3.5 Piping Drawings

Piping Drawings are those documents which define the installation requirements for,

the piping, in-line piping components, and piping supports. Piping Drawingsprovide the requirements for installation so that the piping will fit into thebuilding space allocated to the piping system.

3.6 As-Built Documents

These are the drawings, sketches or other documents which define the as+ installedpiping configuration (nominal dimensions and tolerances) and which have beenreconciled with the stress analysis.

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3.7 installation Tolerance

This is the specified acceptable departure from nominal piping dimensions, supportlocations and orientations, and component weights to be used during installationto provide for practical installation limitations. Installation Tolerances mayapply to CTD or f/C dimensions, installation Tolerances for C10 dimensions.mustbe less--than or equal to the corresponding Total Tolerances. InstallationTolerances are ' determined or accepted by the Owner and Designer and areimplemented by project procedures.

3.8 Total Tolerance

This is the maximum allowable departure between corresponding as-built and as-;

analyzed CTO piping dimensions, support locations and orientations, and componentweights. . The Total Tolerance' is applicable only to -CTD dimensions since f/Cdimensions are not critical to the stress analysis. Acceptable Total Tolerancesare provided in Section 6.

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3.9 Piping Stress Analysis

This is the structural analysis' that determines thepiping internal forces,stresses, bending moments, displacements and - support reactions for particular

1 -loading cases.

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3.10 SuffodThis is a device designed to resist load and limit movemot in one, two, or threeorthogonal directions. Supports are also used to contro' pipe thermal positionand/or to provide dynamic stability by controlling dynamit motion. Included are

springs, saddles, t. angers, struts, snubbers and other support'ng items.

3.11 Anchor

This is a device designed to resist load and bending, anc to limit linearmovements and rotations in three orthogonal directions. Anc hrs are also used tocontrol pipe thermal position and/or to provide dynamic stability by controllingdynamic motion. [quiptrent nortles are of ten considered as anchors.

3.12 De.s3ny

The Designer is the engineer or organization responsible f or the piping systemdesign.

3.13 Owner

The Owner is the organization which will own and operate the installation and whois responsible for establishing the technical requirements, including those forpiping installation.

3.14 Installation

Installation is the process of assembling, welding or attaching the f abricatedpiping subassemblies, the in-line components and the supports of the subjectpiping system.

3.15 Reconciliation

The overall process of confirming that dif ferences between the as-built and as-analyzed piping system are acceptable. This includes acceptance of conditions

within the Total Tolerance and evaluation of those conditions that exceed theTotal Tolerance.

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Section 4

PIPING DESIGN, INSTALLATION, INSPECTION AND RECONClllATION

4.1 General

The process of building a piping system through final acceptance involves manyactivities. The first activity is the functional design of the system whichideally is followed sequentially by engineering, procurement, fabrication,installation, and inspection. The engineering phase includes determining thenominal configuration (including tolerances) of the piping and location ofcomponents (valves, etc.), locating supports and supporting steel, performing thestructural analysis, and structural design (sizing) of pipe and pipe supports(including supplementary supporting steel). These activities result in designdocuments, including design drawings, that are used to prepare detailed

construction and fabrication drawings, and in the procurement and installation ofthe hardware.

The hardware includes material, piping spools and subassemblies, components, cata-log type and job-designed supports, and supplementary steel.

The building structure and major components of a power plant are constructedaccording to rules that permit varied tolerances. Since piping systeminstallation follows construction of the building and installation of the majorcomponents, the piping systems must be permitted to vary within tolerances 50 thatthey will fit within the space allotted to them, in addition, in the modern powerplant there are a large number of systems, all of which must be installed in acertain space allotted to this hardware, it is inevitable that interferences ofone system with another will occur and modification of one or the other systemswithin Installation Tolerances may correct the interference.

The tolerances prescribed in this document bridge the gap between the exactnessasscciated with a design by analysis, and a practical and acceptable installation.

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4.2 Critical-to-Design (CTD) Dimensions and Tolerances

CTD dimensions should be designated in some manner on design documents and theiras-built values reconciled to the tolerances specified for C1D dimensions. The

Total Tolerances given in Section 6 are acceptable CTD tolerances, and should beconsidered as maximum unless larger Total Tolerances are justified by theDesigner. Project Specifications may establish tolerances defined in

Paragraph 3.7 as Installation Tolerances which are less than or equal to the lotalTolerances of Section 6 and which would apply to the dimensions designated as CID.

When a CTD dimension locating a piping item meets the installation tolerance spec-ified, the location of the item is acceptable and need not be evaluated.

4.3 Installation Tolerances

While it is desirable to allow maximum flexibility for construction, other f actorsmust be considered to minimize design revisions and plant modifications,

it is recommended that the Designer consider specifying installation Tolerancesless than the Total Tolerance. This recommendation should help minimite the

number of times the Total Tolerance might be exceeded, thus reducing the number of

design evaluations which may be required. This recommendation is not intended torequire Designers to specify installation Tolerances less than they have used inthe past. Because requirements may vary f rom plant-to-plant, system-to-system,and' arca-to-area within the plant, it is not practical for these Guidelines tospecify a percentage of the Total Tolerance to be used generically as an'

installation Tolerance.

Depending on the space limitations, Installation Tolerances should be established=

to minimize interferences and maintain clearances required for insulation coveringthe pipeline, thermal expansion and access. Clearances for seismic interactionwith sensitive equipment or components should also be considered, The problems

are lessened if all design is completed prior to start of construction and all,

personnel involved in layout of piping, cable trays, HVAC equipment, and otherstructures are f amiliar with the tolerances that are needed by the constructionforces to complete the work in a practical manner.

While the Total Tolerances of Section 6 are acceptable to the piping analysis,care should be taken when defining Installation Tolerances so as not to adverselyaffect other components. Tolerances on piping locations should be coordinatedwith the support tolerances.

4-2

- _ _ _ _ - _

Requirements for reporting dimensions out of installation Tolerance should beprovided in project procedures or stecifications.

Other dimensions exist which are classified neither as f /C or CTD. They nay aid

in the installation, but never control it. Examples include dimensions classified

as "ref erence dimensions." They are not required to be documented or recorded on

As-Built Documents.

4.4 Identify CTO Dimensions and Tole ances

As noted in Section 4.2 CTD dimensions and associated Installation Tolerancesshould be designated on design documents. This is necessary to convey the

requirements to the installer.

CID dimensions may be individually identified on drawings or categories of

dimensions may be identified as CTD or f/C in a procedure or specification.

Alternatively, all dimensions may be considered as CTD because significant

benefits cc still be gained from implementing these Guidelines.

4.5 Weight}

Included in these Guidelines are tolerances on both uniforml) distributed weightsand concentrated weights. Weights are important to the piping stress analysis andto design of supports because weight has a direct relationship to pipe stressesand support reactions. As a practical matter, the concentrated weight of items isa concern primarily for valves and other in line components, but particularly

power operated valves. Changes to the distributed weight of insulation systemsand other piping items should also be considered. Weights of components M rtiallyor totally supported by the pipe such as pipe clamps, other support components and

instruments need not be verified. Weights can most readily he determined fromdocuments received from the supplier of the item, As with CTD dimensions /tolerances, only out-of-tolerance weights need to be evaluated under normalcircumstar es. These items need not be weighed unless the supplier-furnisneddocuments are questioned.

4.6 Mbricationin this Guideline, fabricatton is defined as assembling and joining of materialinto subassemblies or complete components at or away from the plant site prior to

installing them in their final location, lhese Guidelines do not deal with

f abrication tolerances, except when the overall dimensions of the fabricated item

4-3

_ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ - _ _ - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ - _ - _ _ _ - _ _ _ _ _ _ - _ _ _ _ - - _ _ _ _ - _ - _ - _ _ - -

, . ~ _ - . . . _ - - - - - - - - - - - - - - - - -. -- - - . .

.

h

1

are designated as CTO' dimensions. Changes or modifications to f abricated items3

may be important to the design and analysit af Ge piping system (for example,substitution of pipe schedules) but these are not addressed in this Guideline.

,' Fabrication tolerances are covered in Pipe f abrication Institute Standards.2'

4.7 Inspection

Following installation of part or all of a piping system, an inspection is'performed to verify that Instal'ation Tolerances have been met. As a minimum. CTO

dimensions shall 'be measured w thin the accuracy discussed in Section 5. Out of-tolerance CTO dimensions shall be evaluated in accordance with Section 8.0.Inspection of F/C dimensions shall be in accordance with project procedures,

s

48 Modifications

Modifications to the piping system that may be necessary because out of toleranceCTD dimensions cannot be reconciled with the design. Should be handled in

; accordance with established procedures.

4.9 As-Built Documents ,,

t

: "As-Built" Documents are required only to document out-of tolerance CTO dimensionsand weights. Any other requirement _ to prepare As-Built Documents should be

-specified as a requirement by the Owner.

-4.10 Reconciliation

Reconciliation of the Design Report shall b( performed in accordance with NCA-3554' of the ASME Code or -orresponding requirements applicable to the project. This

_

reconciliation shall include evaluation of CTO dimensions and weights that deviatefrom nominal values b) more than the Total Tolerances to assure the design bases,including the appli 2ble design code, have been satisfied. No evaluation is

. required for dipnsions and weights that do not deviate from the nominal values bymore than the Total Tolerances.

-4.11 Final-Walkdowns

Project procedures shall be implemented to control changes following theinspections described in fection 4.7. Final walkdowns have been used -for a

-variety of reasons. However, final walkdowns of the piping system are notrequired to satisfy Section 4.7 after reconciliation has been performed as

-described in these guidelines.

4-4

_ _ _ _ _ . _ _ - _ _ _ , - -_

_ _ _ , , _ . - _ . _ _ _ - , - , _ _ . , , _ . , _

_ _ _ _ _ _ - _ _ - _ - _ _ _ _ - - - - _ _ _ _ _ .

Section 5

MLASURLHENT AC. AACY

Table 5-1 lists the types of measurements to be made and the accuracy (measurementunit) to be reported when performing piping system inspections.

Table 5 1

TYPE Of L' ''JREPENT AND ACCURACY

Type of MeasurementPiping System Characteristics Measurement Accuracy Unit

Piping Configuration

1) Length along pipe centerline to Tared Length 1"centerline of welded or flangedjoints, branch connections,fittings, and valves

2) Bends Arc or chord l"

lengthAngles 2*

3) Angle or slope of pipe legs. Angle 2*

4) Angular orientation of power Angle 2*operated valves

Supports

5) Length along pipe centerline for Length 1"location of supports and restraints

6) Angular orientation of axis Angle 2"(centerline) of supports

The procedures and tools used in taking measurements should be consistent with therequired accurocles. Conventional equipment such as tapes, hand held levels,templates and gages which are normally used by the construction trade may be used.

5-1

- _ _ _ _ - _ _ _ ___ _ _ _ _ _ _ _ _ _--__________-__ - _ - _ - -

_-_ . _ _ _ _ _ _ _ _ - _ _ _

5.1 Angular Measurement

Acceptable forms for angular dimensions are shown ir Figure 5-1. Angular

dimensions are generally denoted on drawings as horizontal angles or verticalangles in degrees and minutes of a degree, as arc lengths or chord lengthsreferenced to a radius in feet and inches, or as of f sets or slopes (of f set to thetangent) in units of 1: u or inches offset in twelve inches of tangent.

5.2 Linear Missurement

Can be made by taping.

5.3 Elevations

May be determitied by optical instruments or tap;. Elevations of piping should bereferenced to established bench marks for the project and determined to thenearest one inch of elevation.

6.4 Methods of Dimensioning

Two common methods of dimensioning piping installations are shown in figure 5-2.Either method or some combination of these methods will usually be used on theDesign Drawings. The chain method references a dimension to the adjacent

dimensions. The common point method references a number of dimensions to a common

base.

5,5 Rounding Off

All measurements should be rounded off to the nearest measurement accuracy unit

given in Table 5-1.

5-2

__ _ _ - _ _ ___ _ - _ _ _ - _ _ _ _ - - - __

_ _ __ _ - _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _

2Af Horizontel, , ,,

'' ,1f)

s

o. ..

'--

1 l

; Section.A-AA3

Rolled Ells

,e

T

/ BendsNon Standard Elis

Valves

10m

osupport 6

Pipe Run

N s

V(Suoports

figure 5-1. Illustrations of Angular Dimensions -Pipe Legs, Valves, Supports, Bends

5-3

_ _ _ . _ _ _ _ - _ _ _ - - - _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

TJg BF.ANCH

[ / Y-r ^ ,,a g.c v- -

1 MetNd 1 - Chain Dimensiot s

L:]

BRANCH,

[~

,

6'' A

B* ,..,

Cy

. _T.at n=

4Method 2 - Cotton Point Dimensions

I Figure 5-2. Illustration of Linear Dimensions

:i3 -

A

9

] 6-4

s

Secticn 6

TOLERANCES

6.1 Total Tolerance

The Total Tolef onces herein are given in terms of the mar in,um allowable plus orminus departure between the as. analyzed (nominal) value and the as-built value.These tolerances should not be used to Circumvent specific requirements

established by the Design or Erection Specification nor other applicabic materialor fabrication standards.

As-built piping systems that conform with the piping stress analysis within theTotal Tolerances are acceptable and evaluation is not required.

6.2 A_Itering Relative Position

Tolerances should not be applied in such a manner that would result in alterationof the relative position of piping components and supports, in no case should thepermissible location change the directions of a restraint or its function.

6.3 Jnsependence

The tolerances given are independent of each other and are not interrelated toposition of adjstent items. Each tolerance may be applied independently of any

othrr.

6.4 Tolerance Categories

The tolerances given are Total lolerances and ar* divided into three categories:

Tolerances for the piping configuration;*

Tolerances for the piping support location and orientation; and*

Tolerances for uniformly distributed and concentrated weights..

Each of these categories is addressed in the following sections.

6-1

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ - _ _ _ _ __________ __ _________-________________ - - --_ -__

6.5 Piping Configura; ion Tolerances

6.5.1 Centerline tenatM. Centerline length to fittings, flanges, valves, andpiping specialties including branch line piping shall be within the tolerancespecified below. (Branch connections are not included. See Section 6.5.2.)

Specified Nominal Olmension : Total Tolerance(feet) (inches)

O to < 5 3

5 to < 10 6

10 to < 15 9

15 to < 20 12

20 tc < 25 15

25 to < 30 18

30 to < 35 21

35 and over 24

Note: The 3-inch tolerance for nominal. dimensions of 0 to less than5 feet may not be generically applicatde. For example, cantileveredvents and drains, relief valve inlet and outlet piping, and instrumentpiping near the connection to the process piping are cases where morerestrictive tolerances may be needed, if so, they must be specified onthe design documents.

Woen common point dimensions (see figure 5-2) are used, the tolerances along thepipe centerline are to be applied to each pipe leg, i.e., piping between changes

in direction. There may be cases where the nominal dimensions must be determinedfrom the difference in common point dimensions for the ends of the pipe leg.

6.5.2 Centerline _. location of Branch Connectionj (relative to run).

The location of branches for branch /run size combinations*

indicated by an asterisk (*) in Table 6 1 have no designrelated tolerance restrictions except when the stress

intensification factor (Sif) exceeds 1.0, in which case themaximum tolerance is +2'.-0".

The location of branches for the branch /run size combinations*

without an asterisk (*) in Table 6-1 have the same tolerance asin 6.5.1.

For all branch /run size combinaticns, changes in location of*

the branch connection that etceed two feet should be approvedby the Designer and should not:

--cha*ge the flow path defined on the piping System diagram;

6-2

_ _ _ _ _ __ _ - _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

._. - _.._._._ _ _-. _ _ . _._ _ _ . _ _ _ _ _ _ _ __ . _ _ _ _ . _ _ _ .

'

--af fect system functional flow and pressure characteristics,such as branch connections used for differential pressure andflow measurement, for safety and relief valves, and for coresafety injection;

--be. allowed without considering the effect cf anchor movementon the branch pipe. (Not significant if the tolerances of6.5.1 are satisfied.)

6.5.3 Angular Deviation of Pipe Centerline. Angular deviation of pipe centerlinefrom theoretical centerline is limited to 110*. See Figure 5-1 - Rolled Ells.

6.5.4 Anqular Tolerance on Power Operated Valves. Angular tolerance on power.

-operated valves over -2- HPS (Nominal Pipe Size) is limited to 115". See

Figure 5-1 - Valves. For power-operated valves 2 NPS and smaller, the angulartolerance of 115' applies only when the weight of the valve operator equals or isless than the valve analyzed weight. When the specified weight of the valveoperator exceeds the valve's .aalyzed weight for a 2 NPS or smaller valve, theangular tolerance shall be established by the Designer. There are no CTDrestrictions on angular orientation of marually operated valves.

6.6. Piping Support Location / Orientation Tolerances

The tolerances provided as. piping support tolerances assume the support is thespecified type and rating - It is not acceptable to change the support type

without approval of the Designer.

These tolerances are applicable to the reconciliation of the piping stress

analysis. -They may :not be applicable for- the reconciliation of the pipe supportdesign.

6.6.1 Location of Supports

Tolerances ' on the location of supports, anchors and restraints along -the pipe-

centerline of horizontal or vertical-straight runs that do not contain significantconcentrated weights are:

pipe Size Tolerance

2'NPS and smaller 26' inches

2-1/2 NPS and larger One pipe diameter or 12 inches.-whichever is greater j

:

6-4

_ _ . - - _ _ __ _ _ . . _ . . . . _ . _ ._ -. _ __ _____ _

._ _ _ . . _ _ _ . _ - - _ . _ , _ _ . _ _ _ _ ~ . . . - _ - _ - . . _ . . . _ _ . _ _ . _-__

6.6.2 Location of the first Support on Eitner Side of Spans that - Contain

Concentrated Weights. Tolerances on the location of the first support or<

restraint on either side of spans that contain concentrated weights such asvalves, flanges, riscrs, fittings, bands or-other concentrated loads are:

Pipe Size Tolerance

12 NPS and smaller Smaller of 3 pipe diameterser 12 inches

Larger than 12 NPS One pipe diameter-

These tolerances may not be applicable to the first restraint adjacent to a bend,which is - oriented in the plane of the bend, -when the piping is subjected towaterhammer,. steranammec, or relief valve ~ discharge loading, in these cases, if i

more restrictivo toleran:es are needed they must be- specified on the designdocuments.

6.6.3 Location'of the First Support from Rotating Equipment Nozzles. Tolerances.

for the location of the first support or restraint in each direction from rotating-

equipment nozzles are:

Pipe Size Tolerance

2 NPS and smaller 3 inches

2-1/2 NPS and larger One-half pipe diameter or6 incnes, whichever is greater

6.6.4 Snubbers. Snubbers with ' axis coincident to the pipe leg centerline may belocated anywhere -along- the length of the pipe- leg regardless of pipe size.

-However, snubbers with- tolerances greater than those of 6.6.1 should be approvedby- the Designer who must assure they are not af fected by the anticipated thermalmovements.-

6.6.5 Angular Orientation of~ Supports. The tolerance for the angular orientationof supports Lis .15*.- (See Figure 5-1 - Supports.) The angular tolerance may beincreased -to'tl0*-'if this value plus the' angularity change from thermal expansion-

of the system does not exceed functional limitations established by the support--

. manufacturer .and the Designer assures that any increased loadings on theconnection are compatible with the design.

6-5

- . - - .- . ___ . - - - , -

. ..- __ __ _ _ . - _ _ _ . . . _ . _ _ _ _ . _ . _ _ . . _ _ _ . . - _ . _ _ _ _ _ _ _ _ _ . - _ . _ _ . . . . . _ _ . - - _ . .

6.7 Weight Tolerances

-6.7.1- Uniformly Distributed Weight. The Unifornly distributed weight estimated

! _

for the piping system may vary by 120% from the as-analyzed weight.

,

This weight tolerance may need to be reduced by the Designer in- the vicinity of'

fixed / rigid supports which are located next to one or a series of variable springsupports.

6.7.2 Concentrated Weight. Documented concentrated weights of in-line items such

as valves, flanges, etc., r ay vary by the greater of 120% of the analyzed weightor 20. pounds.

!

|

6-6

i,

. . _ _ _ _ - . - _ _ - - - - - - . _ - - . - - - -

____ _ ______ _ __ -_______

|

:

Section 7

TOLERANCE JUSTlf!CA110N AND COMENTARY

The approach taken to demonstrate the acceptability of the tolerances given inthis Guideline document was to use simple structural models and fundamentalengineering principles and concepts rather than attempting to analyze an

exhaustive number of typical piping configurations. This inductive method hasconsiderable merit because the ef fects are easily visualized, furthermore, the

simple models are more sensitive to the configuration changes created by thetolerances, and the deviation in calculated stress and loads is more magnified inthese models than in a real piping system. In addition, there is a valuable by-

product to the process, as it demonstrates the appropriate manner for applyingengineering judgment and how that judgment should be backed up by documentedlogic.

To perform detailed analyses of every effect resulting from the published

tolerances is not feasible, because specific pipe geometries and the plus or minusvalues of the tolerances will produce varied results. Further, to assume that

every tolerance will be applied in the most nonconservative manner is not

reasonable nor justified by experience. Experience supports the contention thatthe tolerances can be generally applied without concern for the effects of

interaction or multiple cases of the same out-of-tolerance condition on a givenpipe run.

Each of the tolerance categories of Section 6 is discussed below and the basis foracceptability is given. Additional details of the justification can be found in

WRC Bulletin 316. All mt jels used were based on the chain dimension method

illustrated in Figure 5-2. The common point method that is also allowed is more

restrictive. Therefore, the demonstrations are conservative with respect to thecommon point method.

|

7-l

_ _ _ _ _ _ _ _ _ _ - _ - - - _ - _ _ - - ._ _. -_ -

.. . . - . . . - . _ . . . - - - . . . . - - - - . . - . . . . . . - - - _ - - ~

I:

.7.1 Centerline Length of Pipe Elements (Refer to Section 6.5.1)

The PVRC analytical model Justified the tolerance on the basis of a change in' fundamental- frequency of no more than 10% for the longest length in each specifieddimension group. The relationship is proportional to the square of lengths,(LtdL)2/L where- dL- is the difference between specified length. L. and actual2

length. This same relationship is proportional to the change in bending stress.

7.2 Branchlocations(RefertoSection6.5.2)

Branch /run size combinations in Table 6-1 marked with an asterisk (*) have ratiosof moment of inertia of-the run pipe to the moment of inertia of the branch pipeof 25^or more. A ratio of 25 is considered sufficiently large to permit

separating the branch-line and ren line for structural analysis purposes.

_ _7 . 3 Angular Deviation of Pipe Centerline (Refer to Section 6.5.3)

The primary consideration was the change in frequency resulting f rom a change incenterline length caused by the angular deviation. With a 110' tolerance, the

frequency change is about 3%. The angle change of the actual pipe centerlinecould be as much as 20* without changing the frequency more than 3X,

7.-4. Angular Tolerance on Power-0perated Valves (Refer to Section 6.5.4)

The analytical justification for this tolerance considered the additional stressintensity caused by the eccentric loading of the valve operator rotated 15' from

-the design orientation.,

!*' 7.5 ' Support location-(Refer to Section 6.6.1)

: A- model with four equal- spans compared changes in reactions o_f the ' interior three

supports and changes in fundamental frequencies of the pipeline due to changing-support locations by ' the maximum tolerance. The ' comparison was done for a 1 NPS

system-and'a 12 NPS system.

Maximum _ change in_ the = support reaction ranged from 8.3 to 12.5% and frequency. changes ranged from 4 to 8.5%-for the Y mode and no change for the Z mode.

7.6 Support-Location' Adjacent to Concentrated Weights (Refer to Section 6.6.2)

The two models used to justify'tnis tolerance were similar tc those described inSection 7.5 except they contained three Spans and had a concentrated load placedat the middle of _ the center span. The maximum change in support reactions' Was

7-2

- _ _ _ _ _ _ _ _ _ _ _ _ _ ..- . - . . -- - - . - - - -

~ - - ..~ . . . . . . ~ . . . . - . . . _ - - . . . - - - . - . . . - - - - ~ . . . - . . _ . ~ _ _

about 5% and the change'in frequency in the Y direction was out 8%.

.7.7. Angular Tolerance for Support Axis (Refer to Section 6.6.5)

' A model with four.= spans of 12 NPS pipe with f bed ends, a horizontal reactingcenter support, and two supports reacting vertically was analyzed for gravityloads' and seismic. loads, Various cases of the supports being out of angular

'

alignment by 210' were analyzed and compared. The overall effect of the toleranceof 110' is minor and its use is justified. The maximum change in gravity reactionwas 1.5%, seismic reaction changes ranged from a decrease of 24% to a maximumincrease of '14%. Frequency changes for the first three modes varied from 3% to

.12%.

7.8 Uniformly Distributed Weight (Refer to Section 6.7.1)

This. tolerance was established on the premise that a shift of frequency of 110#, ispermissible.

7.9 Concentrated Weight (Refer to Section 6.7.2)

In order- to cover a wide spectrum, six concentrated weights were used for theevaluation for each-pipe size and schedule, further study was done-for pipe sizesNPS 2-1/2, 4, 8, and 12. Results indicate a 20% change in the concentrated weight

will shif t - the f requency by no more than 10%. Use of the tolerance of 20 pounds

will apply to applications on small bore piping and the larger percentage ofoverweight allowed is- justified because the small bore cookbook analysis isgenerally more conservative than a computer analysis.,

:1

l

:

i

7-3

1

|. _ _ _ _ _ _ _ _ _ _ - ._ _ - _ _ -

'

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .

>

Section 8

EVALVATION Of OUT-Of-10LERANCE CONDil10NS

Af ter design and construction have been completed, it is sometimes necessary toevaluate the effect of an installed condition which is outside of specified

tolerances. This evaluation may be made using engineering judgment, simplifiedmodels, or by reanalyzing the complete original mode'. The objective should be todetermine if the condition being evaluated had any significant effect on the

response of the piping systems to the design loadings and not to impose arbitraryrequirements to fine-tune stress analyses or modify hardware due to calculatedstresses which may result in stress ratios (calculated stress / allowable stress)which may marginally exceed 1.00.

CTD values that do not meet Installation Tolerances shall be recorded andevaluated as required by project procedures. CTD values that exceed TotalTolerances shall be recorded and evaluated by the Designer to assure the designbases, including the applicable design code, have been satisfied. The resolutionmay involve a modification to the piping system and, therefore, the out-of-

tolerance condition should be made known to the Designt * at the earliest possibletime after installation. When a modification to the pipii ' system results from a

ClD tolerance nonconformance, the modification to the piping system must be

reconciled in accordance with Paragraph 4.11.

In evaluating the over tolerance, the Designer may consider details such as

nieasured dimensions, supplementary analysis of simplified models, consideration ofdesign accuracies, rounding-off techniques, typical material properties,

significant figures, and the cumulative effect of engineering conservatisms

associated with the design and analysis process,

if it is determined that there is no significant effect, then the original

analysis remains valid and the results (stress summaries, support design loads,

etc.) need not be revised. The evaluation must be documented consistent withother design calculations. If changes are found to be signifIcant, then the

affected results must be revised.

8-1

.___ ____ _____-__ _______ - --_--___ _ ________ - _ _ - _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ -______ ___-

. . . - - . . . . _ - . - . - - . ~ _ - _ _ . - - . _ - - . . - - -.

i

- When evaluating out-of-tolerance ' conditions, the Designer should corsider thegeneral as-built configuration 'to determine if there seems to be an accumulationof these conditions, If this -is the case, the Designer should evaluate the

effects of the sum of these cunditions as they relate to the design.

8.1 ' Evaluation Using Engineering Judgment

in resolving out of-tolerance conditions, engineering judgment may be used by the

.

Designer. The use of engineering judgment shall be documented with the technicalreasoning described so -that a technically qualified third party reviewer willunderstand how -the evaluation was justified. The documentation requirements for

evaluations -based on engineering judgment shall be consistent with other

engineering calculations. Examples A-2 and A-3 in Appendix A indicate an

acceptable level of justification. The evaluation shall preferably be performedunder the direction of the engineer who has overall responsibility for the finaldesign and analysis of the piping system.

8.2 Evaluation using Simple Structural Models

Evaluations may be based on 'a simple structural model and elastic theory.;

Structural models similar -to those used for justification of the permitted

-tolerance (CTD) in Section 7 should be considered, or models consisting of onlypart of the total- system, for example, vihen a Support location is out-of-

tolerance. -an analysis of a continuous heam that includes the out-of-tolerance

svpport and the two spans on either side of the out-of-tolerance support is

sufficient. The location-of supports adjacent to the out-of-tolerance support maybe either placed at their nominal locations or at their actual position as

___

determined by measurement.

'8.3I Evaluation by Reanalysis

Ifc it is determined that the deviations may not be reconciled by _ engineering--judgment 'or simple s tructural - . mode l s , reanalysis of all or a portion -of theoriginal model may be required. When reanalysis is required, changes to the modelshould include only the .as-installed dimensions which exceed the- TotalTolerances. However, at the discretion of the Designer, other as-installed

- dimensions may also be incorporated.

.

t

, . '

8-2

_. . __ ~ _ .__________ _ _ _

_ . _ . _ . _ _ _ . _ _ . _ . _ _ _ _ _ _ _ _ . . _ _ _ . - . - . _ _ _ _ _ _ _ _ _ _ . _ _

l'j-.

f

i

n

8.4 Model Modification and As-Built Conditions

f. In developing a design, it is necessary to make -a number of assumptions and toestablish a number of parameters necessary to perform the analysis. These include

j such things as support locations, end boundary or fixity conditions, weights,section properties, stif fnesses or flexibilities of piping elements and piping.4

supports, damping factors used in dynamic analysis, and certain material

; properties. The assumptions made and the parameters chosen for design purposes areunc_ertain and can vary over a range of values. Normally, minimum values are

i chosen. However, - in making a design verification of an as-built structure,

whether it be a piping system or some other primary structural system, many of theconservatisms may be modified to more realistic values when the uncertainty

associated with their initial selection can be removed.

8.5 Dynamic-Loading Considerations

When - seismic or ot er building filtered dynamic loadings are controlling, it isrecommended that the analysis for acceptance of the as-installed pipe stresses andsupport loads ba based on the following ASME Boiler and Pressure Vessel CodeCases: Code Case N-411, Alternative Damping Values for Seismic Analysis ofPiping, Section !!!, Division 1, Classes 1,, 2, and 3; and Code Case N-397,

Alternative Rules to the Spectral Broadening Procedures of N-1226.3 for Class 1,2, and 3 Piping, Section III, Division 1. Other improved analyt ital techniquessuch --as applying multilevel spectral analysis in place of more conservativeenvelope approaches should be considered. in addition, the recommendations

outlined in NUREG-1061, Volume 4. Report of the U.S. Nuclear Regulatory CommissionPiping Review Committee, Evaluation of Other Dyr, mic Loads and Lead Combinations,should be reviewed for applicability. When use of these recommendations resultsin eliminating supports and thus increasing piping flexibility, the Designer mustconsider the possibility of increased seismic displacements resulting in

-undesirable impact between critical components (i.e., valve operators) -and othercomponents or structures. Use of these recommendatloas requires approval by theNRC.

8-3

_-_____________: -.. _ _ - _ - - . . . . . _ . .-- - ..._

_ _ _ _ _ . _ . _ . . . . . _ . . . . , ... . . .

Section 9

IMPLEMENTATION SUMMARY

The following is a summary of the activities required to implement these

guidelines on a project:

1. Identify CID dimensions that are to be verified. Determiningwhich dimensions are CTD is a Des'.gner's responsibility.

2. Specify F/C, CID and weight Installation Tclerances.Specifying CTD installation Tolerances is a Desigrer'sresponsibility. The Owner, with input from the Designer,should consider specifying installation Tolcrances smaller thanthe Total Tolerance as discussed in Section 4.3.

3. Make necessary measurements (inspections) of the as-inttalledcondition.

4. Compare measurements with tolerances specified as Installatio-Tolerances and thus determine if all piping items are withmthose tolerances.

5. Document out of specified Installation Tolerance CTD dimensionsand transmit this information to the Designer for evaluation.

6. Evaluate out of Total Tolerance CID dimensions and weights perrequirements of Section 8. Evaluation of out of TotalTolerance conditions is a Designer's responsibility.

7. Evaluate out-of-tolerance F/C dimensions in accordanc'e withproject procedures.

8. Modify the system, when necessary, in accordance withDesigner's requirements when the discrepancy is CTD-related andin accordance with Owner's requirements when the discrepancy isF/C-related.

9. Evaluate modifications starting with item 3. above.

10. Prepare As-Built Documents as required by project

specifications.

9-1

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_ _ _ _ _ _ _ - _ _ - _ _ _ _ _ _ _ _ - _ _ _ _ _.

Appendix A

EXAMPLES

EXAMPLE A-1 FIT / CLEARANCE PROBLEM

EXAMPLE A-2 RECONCILIATION OF A PIPING SYSTEM - EVALUATION OF TWO

OUT-OF-TOLERANCE DIMENSIONS

EXAMPLE A-3 R! CONCILIATION OF PART OF A THREE-DIMENSIONAL PIPING

SYSTEM

A-1

_ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - - _ _ _ _ _ _ - - _ _ _ -

._ __ . __ . . . _ _ - _ _ . . _ . . . . _ _ _ . _ > _ _ . . . . _ . _ . _ _ _ . _ _ . _ _ .

-s

Example A-1-?

flT/ CLEARANCE PROBLEM

Example A-1 illustrates a modification to a piping system to accommodate a changein building structure.

The installer should treat dimensions not identified as CTD as f/Cdimensions th:t are to be worked into the overall fit / clearanceobjective. That is, all piping shown on the drawing that is to berouted in a given area must be made to fit'into that area while -preserving the. fit / clearance requiremtnts that are specified.

for example consider the piping configuration shown infigureA-1(a). If the 3'0" wall opening is actually constructed as2'4" and the right hand wall is shif ted B" to the lef t as shown-inFigure A-1(b). the six foot horizontal legs can be installed as

.

fabricated provided that the 1-3/4" clearance can be tolerated onthe rignt side. In this case, the through wall pipe runs can bepositioned:as shown in figure A-l(b). If the right hand wall is tosupport conduit or other small items requiring more clearance, thenthe horizontal pipe legs can be shortened to $'8" (which is withinCTO tolerance) and the-through wall runs can be positioned as shownin figure A-1(c). In either case, the CTD tolerances are. satisfiedand the F/C dimensions are adjusted to suit-installation conditions.

i-

|1

-!

|

A-2

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_ . . _ . _ _ _ _ _ _. . __..__ _ .__. . . _ _ . _ . - .

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f' * CTD dimension'

' '<>6'- O n x fio insulation#

,,# a s, 4 tips pipe:

| 6'- O" -M'

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6'- O " ++* m-

Plan view

FIGURE A-1(a)

_ 7.- 4" ( As - built)_

2 '- 4 "l' O"_ I o'- 6"I d- d" .-

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Leaving 6' --0" legs as 6' - 0" Shortening 6' - 0" legs to 5' - 8"

FIGURE A-1(b) FIGURE A-1(c)_

EXAMPLE A-1

A-3|

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.._

..

_. . .. . ..

.

. - . _ _

EXAMPLE A-2

RECONCILIATION OF A PIPING SYSTEM

EVAltjATION OF TWO OUT-OF-TOLERANCE DIMENSIONS

c- o"

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'.

f. u\a@ *O:-

ig .gs

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I O'- O" 3 o'- O " $ d 3'-dli i | |

Piping system depicted lies in one plane.All piping is 8" Sch. 40.

TOLER-

VALUE TYPE NOMINAL AS-dVILT DIFF. ANCE ACTION TOL. REF.Length pipe A CTO 5'-0" 5'-1" 1" 6" Accept 6.5.1Length pipe B CTO 10'-0" 10'-6" 6" 9" Accept 6.5.1Length to valve F CIO 4'-0" 4'-2" 2" 3" Accept 6.5.1Length of pipe C CTO 26'-0" 26'-8" 8" 18" Accept 6.b.1Length of pipe O CTO 30'-0" 30'-2" 2" 21" Accept 6.5.1-Length of pipe E CTO 20'-0" 19'-6" 6" 15" Accept 6.5 t

Length of pipe F CTO S'-0" 4'-3" 9" 6" Evaluate 6 . '. .FLength pump G F/C 3'-0" /A

Valve F orientation CTO E E 12" N 12" 15' Accept o.h.4Valve F weight CTO 6000 lb 6800 lb 13% 20% Accept 6.7.2Support b location CTO 12' D" 10'-9" 15"~ 12" Evaluate 6.6.2Support c location CTO 10'-0" 9'-6" 6" 6" Accept 6.6.3Suppor_t c orientation CID Vert. 10* 10* 10* Accept 6.6.5Support a location CTO l'-0" l'-0" 0" N/A N/A Np _

_

A-4

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. . - , . - - . -. - - _ . - - - . - . _ . - . _ - -- - . - . -

Example A-2 (cont.)'

-Evaluation q',relecation of support "b":

-CTD diman '.on, nc.inal 12'-0" l

As-built o.mension 10'-9"

Total Tolerance'(Section 6.6.2) 12"Deviation- 15"

Deviation over tolerance 3"

Evaluation: Due to longer effective' spans, the out of plane direction is morecritical. The effective nominal span from "b" to "c" is 32 feet,

and~from "b" to'the equipment (tank) nozzle is 29 feet. Adeviation of 3" in excess of the tolerance for the support isinsignificant for spans of this length. This is consistent withthe pipe ler.gth tolerance which is 18"-21" for these lengths(Section 6.5.1).

Evaluation of'Out-of-Tolerance on-Pipe Length "F" (5' dimension):

CTD dimension, nomimal 5'-0"As-built dimension- 4'-3"

Total Tolerance (Section 6.5.1) 10'-6"Deviation:. (4'-3") - (5'-0") - -O'-9'

Evaluation:

a): Span.l. is~ reduced,-therefore gravity stresses are less than designed.-

b) 'A 9" shortening of a. length that exceeds 15' will have a negligible effect .Ion' flexibility of the system, and hence on thermal stresses.

c)_ The excitation in the out-of-plane direction is more critical to-evaluate- D

-due to the change in length--!'F"- than excitation in:the plane of thepaper. The effective span-in;this direction-can be approximated as thelength between-the pump and support C (10' + 20' + 5' = 35'). Thetolerance on 35''(per Section 6.5.1) is 21". Since this is greater than9", the deviation is acceptable in this-direction.

The.out-of-tolerance pipe element F is acceptable. '

l

|

A-5

______ _ _. __ _ __ _ .

_ . _ . . . - _ . . . _ . __ _. _ _ . _ . .-

EXAMPLE A-3

RECONCILIATION OF PART OF A THREE DIMENSIONAL PIPING SYSTEM

SJ

S4 #b5& f/

s /p

S28 B f -

o,. $'

g( ,p '~

d "

e; ;-c.o a,3/ /

/ i.

Af*f / ,,, n " ay

?gd'/.G

O'' y

|:'3. k"45* V / .

p

(QonyshownifdifferentS8 S6 W. %" As-built dim.'

% . -

1/ from nominal)

'h z

Figure A-3. Piping Configuration and Support Locations

A-6

_ _ _ _ _ _ _ . _ _ _ ..

_ _ _ _ _ _ _ _

Example A-3

] COMPARISON Of NOMINAL WITH AS-BUILT O!MENSIONS

Measurement Nominal As-Built Diff. Tolerance

Len E-f 3'10" 3'4" 6" 3"*

Ang E-f fromX-Y plane 0* 2' 2 '' 10"

Len SS-G 3'7" 3'6" 1" 3"

Ang G-H fromX-Y plane 0* 26' 26* 10"*

Vert. Dist G-H l'0" l'2" 2" 3"-

* Difference exceeds tolerance.

Evaluation

1) The pipe length E-f is 3" shorter than the tolerance allows. Adjacent Ysupports are S4 and 58. This is a short span with a riser at each end,reducing the horizontal distance 3" is insignificant. Adjacent Z supportsare 54 and S6. The total length of this span is approximately 24'. A

6" change is insignificant. Adjacent X supports are S3 and SS since thelength change is in the I direction, there is no significant effect.

Reducing the length E-f by 6 inches will reduce the flexibility forexpansion in the Y direction between S4 and 58. However, the flexibilityof the 14' run 0-E makes a 6" reduction in E-f insignificant.

Accept as-is

2) The run G-H has been rotated 26' from the XY plane. Due to the shortlength of G-H, this change has no significant effect on the stressanalysis.

Accept as is

A7

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Appendix B

NCR LETTER ACCEPTING GUIDELINES FOR PIPING SYSTEMRECONCILIATION (NClG-05, REVISION 1)

._-

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|l

f* ** Goi *f, , , , UNITED sT Al[sy 3 e, g NUCLEAR REGULATORY COMMISSION

';L, WASWNGTON, O C. ?O555t

% . . . . * j''OB3 1988

Mr. Walter H. Weber, ChairmanNuclear Construction issues GroupUnion Electric Company2815 Scott AvenueSt. Louis, M0. 63103

SUBJECT: GUIDELINES FOR PIPING SYSTEM RECONCILIATION (NCIG-05, REVIS10n 1)

REF: Letter from Walter H. Weber to Robert J. Bosnak dated December 17,1987

Dear Mr. Weber:

The staff has completed review of the subject document prepared by the NuclearConstruction Issues Group. We have concluded that NCIG-05, Rev. 1, representsa technically acceptable approach for perfonning reconciliations of the asbuilt installation of piping systems with the as-analyzed piping system. Itprovides guidelines acceptable to the staff for implementing Pressure VesselResearch Committee (PVRC) position paper " Technical Position on Piping SystemInstallation Tolerances" which has been published as Welding Research Council(WRC) Bulletin 316 The staff's acceptance should not, however, be construedto replace any specific licensing crf +eria or licensing consnitments in thearea of safety related piping system design.

It should be noted that the staff's endorsement of the guidelines in NCIG-05Rev. 1, is subject to the restriction that the acceptable as built pipingtolerances not be increased beyond those stated in NCIG-05, Rev. I and thatthey be limited to piping systems analyzed using linear elastic methods andqualified on the basis of currently accepted design criteria as specifiedin any of the ASME Codes or other more conservative standards. Currently, thestaff's endorsement is limited to piping systems where conventional seismicanalysis methods have been used. This includes methods approved in currentlicensing documents. Use of the guidelines for piping systems where otherseismic analysis techniques or less conservative design criteria have been usedmay be appropriate; however, such use of the guidelines shall be approved byNRC on a case specific basis. Examples of currently used seismic analysistechniques for which the staff is not generically endorsing the guidelinesinclude: time history analysis anTTnelastic analysis methods. Genericendorsement of the guidelines applies to editions and addenda of Section !!! ofthe BAPV Code as referenced in 10 CFR 50.55a and those piping design Code Casesas listed in Regulatory Position C.l.a of Regulatory Guide 1.84

B-3

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..

... .

. . - - _

|

FEB 3 1988

?

Applicants and licensees wishing to use NCIG-05, Rev. 1, for piping systerreconciliation cust comit to its use and document that comitment in theplant specific Design Specification.

The use of NClG-05, Rev.1, including the resolution of questions on itsapplicability and its proper implementation in plant specific cases, is theresponsibility of the Office of Nuclear Reactor Regulation, inquiries

concerning the use of NCIG-05, Rev. 1 in plant specific situations should bedirected to Mr. James E. Richardson, Assistant Director for Engineering.Office of Nuclear Reactor Regulation, NRC.

Since aly,

f,-'

. Arlotto Director/ Guy ADivis ton of EngineeringO f fic e of Nuclear Regulatory Research

cc: S. Sills, NCIGR. Reedy, NCIGJ. Carey, EPRIW. Bilanin, EPRI

|

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