Assessment of Socket Weld Integrity in Pipings (2)

Code Acceptance of Overlay Repair of Socket Weld Failures Technical Assessment

1003165 Effective October 22, 2009, this report has been made publicly available in accordance with Section 734.3(b)(3) and published in accordance with Section 734.7 of the U.S. Export Administration Administration Regulations. As a result of this publication, this report is subject to only copyright protection and does not require any license agreement from EPRI. This notice supersedes the export control restrictions and any proprietary proprietary licensed material notices embedded in the document prior to publication

Code Acceptance of Overlay Repair of Socket Weld Failures

1003165 Technical Assessment, December 2001

EPRI Project Manager Greg Frederick

RRAC Coordinator Mike Sullivan, PG&E

EPRI-RRAC EPRI-RRAC  1300 W.T. Harris Blvd., Charlotte, NC 28262 • PO Box 217097, Charlotte, NC 28221 • USA 704.547.6100 • [email protected] • www.epri.com www.epri.com

DISCLAIMER DISCLAIMER OF WARRANTIES AND LIMITATION OF LIABILITIES LIABILITIES THIS DOCUMENT WAS PREPARED BY THE ORGANIZATION(S) NAMED BELOW AS AN ACCOUNT OF WORK SPONSORED OR COSPONSORED BY THE ELECTRIC POWER RESEARCH INSTITUTE, INC. (EPRI). NEITHER EPRI, ANY MEMBER OF EPRI, ANY COSPONSOR, THE ORGANIZATION(S) BELOW, NOR ANY PERSON ACTING ON BEHALF OF ANY OF THEM: (A) MAKES ANY WARRANTY OR REPRESENTATION REPRESENTATION WHATSOEVER, EXPRESS OR IMPLIED, IMPLIED, (I) WITH RESPECT TO THE USE OF ANY INFORMATION, APPARATUS, METHOD, PROCESS, OR SIMILAR ITEM DISCLOSED IN THIS DOCUMENT, INCLUDING MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, OR (II) THAT SUCH USE DOES NOT INFRINGE ON OR INTERFERE WITH PRIVATELY OWNED RIGHTS, INCLUDING ANY PARTY'S INTELLECTUAL PROPERTY, OR (III) THAT THIS DOCUMENT IS SUITABLE TO ANY PARTICULAR USER'S CIRCUMSTANCE; CIRCUMSTANCE; OR (B) ASSUMES RESPONSIBILITY FOR ANY DAMAGES OR OTHER LIABILITY WHATSOEVER (INCLUDING (INCLUDING ANY CONSEQUENTIAL DAMAGES, EVEN IF EPRI OR ANY EPRI REPRESENTATIVE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES) RESULTING FROM YOUR SELECTION OR USE OF THIS DOCUMENT OR ANY INFORMATION, APPARATUS, METHOD, PROCESS, OR SIMILAR ITEM DISCLOSED IN THIS DOCUMENT. ORGANIZATION(S) THAT PREPARED THIS DOCUMENT EPRI Pacific Gas & Electric

NOTICE: THIS REPORT CONTAINS PROPRIETARY INFORMATION THAT IS THE INTELLECTUAL PROPERTY OF EPRI, ACCORDINGLY, IT IS AVAILABLE ONLY UNDER LICENSE FROM FROM EPRI AND MAY NOT BE REPRODUCED OR DISCLOSED, WHOLLY OR IN PART, BY ANY LICENSEETOANYOTHER PERSONORORGANIZATION.

This is an EPRI Level Level 2 report. A Level 2 report is intended as an informal informal report of continuing continuing research, a meeting, or a topical study. It is not a final EPRI technical report.

ORDERING INFORMATION Requests for copies of this report should be directed to the EPRI RRAC, 1300 W.T. Harris Blvd., Charlotte, NC 28262, (704) 547-6176. Electric Power Research Institute and EPRI are registered service marks of the Electric Power Research Institute, Inc. EPRI. ELECTRIFY THE WORLD is a service mark of the Electric Power Research Research Institute, Inc. Inc . Copyright Copyright © 2001 2001 Electric Power Research Institute, Inc. All rights reserved.

CITATIONS This document was prepared by EPRI, Repair and Replacement Application Center 1300 W.T. Harris Blvd. Blvd. Charlotte, NC 28262 Principal Investigator G. Frederick Pacific Gas & Electric E lectric 3400 Crow Canyon Rd. San Ramon, CA 94583-1308 Principal Investigator Mike Sullivan This document describes research sponsored sponsored by EPRI, E PRI, Repair and Replacement Application Center. The publication is a corporate document that that should be cited in the literature in the following manner: Code Acceptance of Overlay Repair of Socket Weld Failures, EPRI-RRAC, Charlotte, NC: 2001.

1003165.

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EPRI Proprietary Licensed Material

SUMMARY Failures of small bore piping connections (2-inch and smaller) continue to occur frequently at nuclear power plants in the United States, resulting in degraded plant systems and unscheduled plant downtime. Fatigue-related failures are generally detected as small cracks or leaks but, in many cases, the leak locations are not isolable from the primary reactor reactor coolant system, resulting in extended outages. Outages associated associated with fatigue failures failures have resulted in shut downs as long as 7 days with lost revenue costs exceeding $300K per day. To reduce costs associated with these common c ommon failures of small bore piping and fittings, EPRI has conducted several studies to improve socket weld design, fabrica fabrication tion practices and repair rep air applications to address high high cycle fatigue. One of the options evaluated was an overlay repair of the leaking connections which was intended to extend the life life of a failed failed connection and allow replacement to be scheduled during a routine outage. Preliminary Preliminary results indica indicating ting that seal welding and overlay weld repairs can provide a fatigue life equal to the original 1:1 code weld geometry. As a result, result, Code Case N-XXX, Alternative Rules for Repair of Class 1,2, and 3 Socket Welded Connections was was drafted to support the on-line repair of leaking socket welded connections. The goal of this program is to support the Code Case to permit the use of this repair technology for on-line repairs of leaking socket welds in operating nuclear plants, including high cycle fatigue and MIC. To validate the repair technology a series of mockup configurations representative of plant components will be tested. The mockup configurations will include a range of socket weld pipe diameters, materials and initial failure modes to substantiate the repair approach. The purpose of the test matrix is to provide experimental confirmation confirmation that an overlay repair would allow the socket weld to remain r emain in service or allow replacement at a scheduled outage. An ASME task group has been been established to review review the Code Case and test matrix. ma trix. The latest revision of the Code Case, test matrix and preli pr eliminary minary results are included in this progress report. The final report with all a ll test results, conclusi co nclusions ons and ‘Position Paper’ will be completed c ompleted in in the early 2002.

v


vi


CONTENTS INTRODUCTION ................. ................. .................. .................. ................. ................. .................. ................. ............... ....... 1-1 1 INTRODUCTION......... 2 TEST 2 TEST PROGRAM ................ ......................... ................. ................. .................. ................. ................. ................. ............... ....... 2-1 Test Matrix........................................................................ Matrix.................................................................................................. ...................................... ............ 2-1 Test Procedures Procedures........................... ...................................................... ...................................................... ............................................... .................... 2-2 Shaker Table Assembly ...................................................... ................................................................................. .............................. ... 2-3

3 TEST 3 TEST RESULTS .................. .......................... ................. ................. ................. .................. ................. ................. ................ .......3-1 3-1 A APPENDIX: CODE CASE................... CASE............................. .................... .................... .................... .................... .......... A-1

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1

INTRODUCTION Failures of small bore piping connections (2-inch and smaller) continue to occur frequently at nuclear power plants in the United States, resulting in degraded plant systems and unscheduled plant downtime. Fatigue-related failures are generally detected as small cracks or leaks but, in many cases, the leak locations are not isolable from the primary reactor reactor coolant system, resulting in extended outages. Outages associated associated with fatigue failures failures have resulted in shut downs as long as 7 days with lost revenue costs exceeding $300K per day. To reduce costs associated with these common c ommon failures of small bore piping and fittings, EPRI has conducted several studies to improve socket weld design, fabrica fabrication tion practices and repair rep air applications to address high high cycle fatigue. One of the options evaluated was an overlay repair of the leaking connections which was intended to extend the life life of a failed failed connection and allow replacement to be scheduled during a routine outage. Preliminary Preliminary results indica indicating ting that seal welding and overlay weld repairs can provide a fatigue life equal to the original 1:1 code weld geometry. As a result, result, Code Case N-XXX, Alternative Rules for Repair of Class 1,2, and 3 Socket Welded Connections was was drafted to support the on-line repair of leaking socket welded connections. The goal of this program is to support the Code Case to permit the use of this repair technology for on-line repairs of leaking socket welds in operating nuclear plants, including high cycle fatigue and MIC. To validate the repair technology a series of mockup configurations representative of plant components will be tested. The mockup configurations will include a range of socket weld pipe diameters, materials and initial failure modes to substantiate the repair approach. The purpose of the test matrix is to provide experimental confirmation confirmation that an overlay repair would allow the socket weld to remain r emain in service or allow replacement at a scheduled outage. An ASME task group has been been established to review review the Code Case and test matrix. ma trix. The latest revision of the Code Case, test matrix and preli pr eliminary minary results are included in this progress report. The final report with all a ll test results, conclusi co nclusions ons and ‘Position Paper’ will be completed c ompleted in in the early 2002. The test procedures and and test matrix are documented in Section 2, Preliminary Preliminary Results are documented in Section 3 and the draft draft Code Case is included in Appendix A. The final report with all test t est results, conclusions and ‘Position Paper’ will w ill be completed in the the early early 2002.

1-1


1-2


2

TEST PROGRAM The test program is divided into two sections; 1) Test Matrix and 2 )Test Procedures.

Test Matrix A test matrix was outlined by the ASME task group formed to support the Code Case on overlay weld repair. The test matrix was to include include a range of pipe sizes, sizes, materials and failure failure modes to assure the repair repair technology would cover most failures failures in a power plant. plant. The group elected to test common nominal pipe sizes (3/4-inch (1.91 cm) and 2-inch (5.08 cm) NPS) and typical materials (stainless steel and carbon steel). A test matrix consisted of standard equal leg (1:1) soc ket welds fabricated from Schedule 80 piping and standard pipe to pipe couplers. couplers. Loading amplitudes were selected based on fatigue data from prior socket sock et weld fatigue tests, and desired failure modes (toe and root failure modes). The final test matrix is shown in Table 2-1. Table 2-1. Proposed Test Matrix for Socket Weld Overlay Code Case Base Material

Size

Test Specimens and Stress Conditions Original Crack Stress Range Location

Number of Specimens

2”

Toe

High Low

3 3

2”

Root

High Low

3 3

¾”

Toe

High Low

2 2

¾”

Root

High Low

2 2

2

Toe

High Low

3 3

2

Root

High Low

3 3

Stainless Steel

Carbon Steel

2-1


Test Procedures The high cycle fatigue testing of socket welds has been developed o ver the past few years at PG&E to accommodate typical socket socket weld configurations. The testing method method is displacement controlled, peak-to-peak, with the specimens vertically cantilevered on a shaker table as seen in Figure 2-1. Each set of socket weld weld specimens is bolted bolted to the shaker table and and shaken simultaneously near their resonant frequencies frequen cies to produce the desired stress amplitudes and cycles per Table 2-1. A typical caniliver specimen is shown shown in Figure 2-2. The test matrix consisted of standard equal leg (1:1) socket welds fabricated from common p ipe sizes and diameters. The specimens are processed processed on the Shaker Table Assembly until they fail. fail. The socket weld connections are processed at various stress ranges to promot e through-wall toe t oe and root crack failures. failures. The failed specimens are seal welded and overlay repaired in accordance with the proposed Code Case (Appendix (Appendix A). The leaks will be peened, with water in the pipe pipe at pressure, to allow a seal seal weld to be applied. applied. Most of the specimens will be overlay repaired while the pipe pipe is filled with with water and pressurized. Select specimens will be repaired repaired without water backing. The weld overlay will be ap plied in accordance to the dimensions dimen sions illustrated illustrated in the Code Case. The overlay design governed by the Code Case applies a sufficient reinforcement reinforcement to cover cove r the possibility possibility of either a toe or a root failure. failure. The overlay design adds 0.77tn (tn = pipe wall thickness) to the weld throat across the en tire profile, profile, from the pipe side toe to the fitting fitting side toe. The thickness is measured from the seal weld and not the existing toe. The weld is is applied by by shielded metal arc welding (SMAW) to simulate the most likely welding process that would be used for in-line repair in a power plant. The overlaid specimens are again processed on the the Shaker Table Assembly un til til failure fa ilure or until the specimen exceeds the original number of cycles to failure failure (run-out). The repaired specimens specimens 6 will be tested at a high stress range (failure in <10 cycles) and a low stress range (failure in >10 7 cycles).

Figure 2-1. Shaker Table Assembly

2-2


( 1 4 . 2 5 i n . )

Test Weld

(6.5-in.)

Figure 2-2. Test Specimen Details

Shaker Table Assembly Different load amplitudes can be applied ap plied to different samples samples in the same test by fine-tuning the specimen natural frequencies relative relative to the shaker table table excitation frequency. The shaker table typically operates at 100-110 Hz and the test specimens specimens had natural frequencies that were nominally 4-8 Hz lower lower than the excitation frequency. By adding or subtracting subtracting small masses, such as nuts and washers, the frequencies of the test specimens were moved enough off resonance to adjust each individual response acceleration. The specimen are instrumented with an accelerometer and a pressure gauge, and are monitored continuously during testing. The specimens were pressurized with air to a moderate pressure of approximately 50 psig psig (344.75 kPa). Failure of a specimen is indicated when depressurization occurres, the specimen are removed re moved from the table at the next next convenient conve nient test stoppage point, and the testing is resumed with w ith the remaining specimens. Figure 2-3 illustrates the actual test apparatus apparatus with with all monitroing equipment equipment attached. The tubes and wires are leads for the strain gages and pressure transducers, which were relayed to the test control computer (right side side of figure). The desired stress stress level for each test specimen was precalculated as a top mass acceleration and was adjusted to produce a particular failure modes (toe or root failure). failure). The shaker table table amplitude was computer-controlled to achieve achieve a preset accelerometer amplitude on one of the mounted samples. The accelerometer amplitude amplitude is recorded for all samples and is used to determine the tested stress amplitude for each specimen.

2-3


Figure 2-3. Test Apparatus with test control computer on right)

2-4


3

TEST RESULTS A number of the overlay o verlay test specimens from the test matrix shown in Table 2-1 were tested in accordance to the test procdures in in Section 2. The status of the test test matrix is is documented in in Table 3-1 and the preliminary results are shown in Figure 3-1 for 2-in. stainless steel, Figure 3-2 for 2-inch carbon steel and Figure 3-3 for for ¾-inch stainless steel. At this this time, additional additional toe failures are needed to complete co mplete the original test matrix. matrix. Further evaluation of the test specimens will be conducted once the entire test matrix has been completed. Each specimen will be compared to the original fatigue life and metallographically evaluated to determine failure mode (i.e. crack initiation initiation site and crack extension). Results will will determine if the weld overlay repair process was successful in restoring or improvin g the original fatigue strength of the specimen. At the completion com pletion of the entire test matrix and failure analyses a final report r eport with all test results, results, conclusions and ‘Position ‘Position Paper’ will be completed. com pleted. The expected completion date is March 2002. The position position paper will be presented presented to the ASME task group group for review at th at time. time.

Table 3-1 Socket Weld Test Matrix Status Base Ma Material

Size

Stainless Steel

2”

Toe

High Low

3 3

2 0

2”

Root

High Low

3 3

2 5

¾”

Toe

High Low

2 2

1 2

¾”

Root

High Low

2 2

3 2

2

Toe

High Low

3 3

0 0

2

Root

High Low

3 3

2 4

Carbon Steel

Original Crack Location

Stress Range

3-1

Number of Specimens

Completed


2" Stainless Steel Socket Welded Specimens Weld Overlays are solid symbols; Original c racked socket welds are open symbols

100000

Higuchi B7-2SS-5 B7-2SS-6 B7-2SS-7 B7-2SS-2 B7-2SS-3

) i s p ( e d u t i l p 10000 m A s s e r t S

B7-2SS-4

6rr

3tr

3

1

2

B7-2SS-8

2r>

1tt 6r>

5rt

5

4

6 9

7

9rr 8rr

B7-2SS-9 B7-2SS-3-wor

7rr 4r>

B7-2SS-5-wor B7-2SS-6-wor

8

B7-2SS-2-wor B7-2SS-4-wor B7-2SS-7-wor B7-2SS-8-wor B7-2SS-9-wor B7-2SS-6-wor/ro B7-2SS-1 B7-2SS-1-wor

1000 100000

1000000

10000000

100000000

# of cycles

Figure 3-1. Preliminary Results of 2-inch Stainless Steel Steel Test Specimens

3-2


2" Carbon Steel Higuchi Curve with our Test Results Weld Overlays are solid symbols; Original cracked socket welds are open symbols

100000

Higuchi B8-2CS-1 B8-2CS-4 ) i s p ( e d u t i l p 10000 m A s s e r t S

B8-2CS-5 5

9

B8-2CS-6

6rt 5rr

B8-2CS-8

1

9r> 4r> 8r> 1r>

B8-2CS-9 B8-2CS-10 B8-2CS-1wor B8-2CS-4wor B8-2CS-5wor B8-2CS-6wor B8-2CS-8wor B8-2CS-9wor


2" Carbon Steel Higuchi Curve with our Test Results Weld Overlays are solid symbols; Original cracked socket welds are open symbols

100000

Higuchi B8-2CS-1 B8-2CS-4 ) i s p ( e d u t i l p 10000 m A s s e r t S

B8-2CS-5 5

B8-2CS-6

6rt 5rr

9

B8-2CS-8 9r> 4r> 8r> 1r>

1

B8-2CS-9 B8-2CS-10 B8-2CS-1wor B8-2CS-4wor B8-2CS-5wor B8-2CS-6wor B8-2CS-8wor B8-2CS-9wor

1000 100000

1000000

10000000

100000000

# of Cycles

Figure 3-2. Preliminary Results of 2-inch Carbon Steel Test Test Specimens

3-3


3/4" Stainless Steel Higuchi Curve Curve with our Test Results Weld Overlays are solid symbols; Original cracked socket weld are open symbols

100000

4

5 6

3

4tr 1

1rt

10000

7t> 7

Higuchi B9-34SS-1 B9-34SS-2 B9-34SS-7 B9-34SS-8 B9-34SS-3 B9-34SS-4 B9-34SS-5 B9-34SS-6 B9-34SS-1 B9-34SS-2 B9-34SS-7 B9-34SS-8 B9-34SS-3 B9-34SS-4 B9-34SS-5 B9-34SS-6

wor wor wor wor wor wor wor wor


3/4" Stainless Steel Higuchi Curve Curve with our Test Results Weld Overlays are solid symbols; Original cracked socket weld are open symbols

100000

4

5 6

3

4tr 1

1rt

7t> 7

10000

Higuchi B9-34SS-1 B9-34SS-2 B9-34SS-7 B9-34SS-8 B9-34SS-3 B9-34SS-4 B9-34SS-5 B9-34SS-6 B9-34SS-1 B9-34SS-2 B9-34SS-7 B9-34SS-8 B9-34SS-3 B9-34SS-4 B9-34SS-5 B9-34SS-6

1000 100000

1000000

100 00000

Figure 3-3. Preliminary Results of 3/4-inch Stainless Steel Test Test Specimens

3-4


A APPENDIX: CODE CASE

10000 0000

wor wor wor wor wor wor wor wor


A APPENDIX: CODE CASE

A-1


A-2


Case N-XXX Alternative Rules for Repair of Class 1, 2, and 3 Socket Welded Connections Section XI, Division 1

Inquiry: Under the the rules of IWA-4611, structural integrity of components containing unacceptable defects may be restored by defect removal removal and repair. As an alternative to defect removal and repair of a cracked or leaking socket weld where the failure is predominantly a result of vibration fatigue, is it permissible to restore the structural integrity by installation of weld reinforcement (weld overlay) on the outside surface of the pipe, weld, and fitting?

Addenda, refer to Table 1 for applicable references. (b) Use of this Code Case is limited to Class 1, 2, or 3 NPS 2 and smaller socket welded connections with base material of PNumber 1 Group 1, P-Number 1 Group 2, or P-Number 8. (c) Reinforcement Reinforcement weld weld metal metal (structural and seal layers) shall be deposited in accordance with a welding procedure specification qualified in accordance with IWA-4440. (d) The repair repair shall be be acceptable acceptable for service for one refueling cycle if no action is taken to determine the cause of the vibration and to reduce it it to acceptable levels. The repair shall be acceptable for the remaining life of the piping system if corrective action is taken to reduce vibration to acceptable levels. When the time to failure of the original socket weld was less than one fuel cycle, then corrective action to reduce the vibration to acceptable levels must be taken. (e) This case can only be applied once per socket weld. A socket weld may may not be reinforced more than one time. (f) All other other applicab applicable le requir requiremen ements ts of IWA-4000, IWB-4000, IWC-4000, or IWD4000 shall be met.

Reply: It is the opinion opinion of the Committee that, in lieu of the requirements of IWA4611, the structural integrity of a cracked or leaking socket weld in Class 1, 2 and 3, NPS 2 and smaller piping may be restored by deposition of weld reinforcement (weld overlay) on the outside surface of the pipe, weld and fitting, provided the requirements of this case are met:

1.0 General Requirements

(a) The repair shall be be performed performed in accordance with a Repair Replacement 1 Program satisfying the requirements of IWA-4150 in the Edition and Addenda of Section XI applicable to the plant in-service inspection program, or later Edition and Addenda of Section XI. The references used in this Case refer to the 2001 Edition of Section XI. For use with other Editions and

2.0 Evaluation

(a) Determine Determine that that the socket weld weld failure mechanism is predominantly a result of vibration vibration fatigue. This determination, determinat ion, as a minimum, should be based on review of the design, operating history, and the visual inspection of the failed socket weld. Metallurgical analysis of the flaw surface for failure determination is not required.

1

When applying this Case to Editions and Addenda later than the 1989 Edition, reference to Repair Program shall be read as Repair Plan.

A-3


(b) Verify that pipe pipe base material material adjacent to the socket weld requiring repair meets design minimum wall thickness. (c) Evaluate the effect of water backing on the repair

4.0 Procedure

(a) Prior to repair, visually examine the socket weld to determine the location and approximate extent of cracking. (b) Seal the crack by depositing one or more weld beads directly over the crack. Peening may be used in combination with welding to seal the crack. (c) VT-1 examine the seal weld, remaining socket weld and weld and adjacent base material that will be reinforced. Visual examination shall be performed with a minimum 8X magnification and shall verify that the leakage has been stopped and the surface is dry and suitable for structural reinforcement (d) Deposit two or more structural reinforcement layers around the entire circumference of the fitting, weld, and pipe. The minimum required deposit length, throat and leg dimensions shall be in accordance with Figure 1. The throat and leg dimensions shall not include the seal layer(s) deposited in accordance with 4(b) above. The weld surface need not be ground; an aswelded surface is acceptable.

3.0 Design

(a) The intent of the design is to restore the integrity of the welded connection such that the fatigue life is at least equal to that of a new new standard socket weld. The source of the vibration that failed the original socket weld will also eventually fail the overlaid socket weld unless measures are taken to identify and mitigate the vibration. The owner shall consider this in the suitability evaluation required by IWA-4160. (b) The completed weld reinforcement repair shall meet the dimensional requirements specified in Figure l. The minimum reinforcement dimensions also apply when the fatigue crack is located in the base metal adjacent to the toe of the socket weld. The minimum reinforcement dimensions shall be measured from the location of the crack furthest from the weld toe. (c) The filler metal for structural reinforcement of P-No. 1 materials shall be AWS Class E70XX-X or ER70S-X. Filler metal for structural reinforcement of P-No. 8 materials shall be AWS Class E3XX-XX or ER3XX. The filler filler metal for for the seal weld may be any filler metal permitted by a qualified welding procedure specification. (d) Evaluate all relevant applied loads in the system. (e) C2 and K2 (reference NB-3680) or i (reference NC-3673) values for the repaired socket weld shall be the same as for a standard socket weld. (f) For Class 1 piping, evaluate the effect of the increased mass of the reinforced weld on thermal stress.

5.0 Examination and Testing

(a) Examina Examination tion of the the final final structural structural reinforcement weld shall be performed in accordance with (1) or (2) below: (1) (1) The The com comp pleted ted str structur cturaal reinforcement weld shall be examined in accordance with the Construction Code identified in the Repair/ Replacement Plan. Type of examination and coverage shall be the same as that specified for a standard socket weld.

A-4


(2) (2) When the the sys system tem ope operati ratin ng temperature exceeds the temperature at which a specified surface examination can be performed, a VT-1 examination may be performed as an alternative. This VT-1 examination shall be performed with a minimum of 8X magnification. Visual indications shall be evaluated using the surface examination acceptance criteria of the Construction Code specified in the Repair/Replacement Plan (b) Following Following completi completion on of all repai repairr activities, the affected restraints, supports, and snubbers shall be VT-3 visually examined to determine that design tolerances are met. (c) A sys system tem leak leakage age test shall shall be be performed in accordance with IWA 5213.

6.0 Documentation

Use of this code case shall be documented on an NIS-2 form.

A-5


TABLE 1 References for Alternative Editions and Addenda of Section XI 1995 Addenda through 2001 Edition

1991 Addenda through 1995 Edition

1988 Addenda through 1990 Addenda

1983 Winter Addenda through 1987 Addenda

4110 Scope 4120 Applicability

4110 4120 (91A-92E) 4111 (92A to 95E)

4110 & 7110 7400

4110 & 7110 7400

4150 R/R Program and Plan

4140 & 4170

4120 & 4130 & 7130

4160 Verification of Acceptability

4150

7220 & 4130

4130 & 4120 7130 added W85A 7220 & 4130

7220 & 4130

4180 Documentation

4910

4800 &7520

4700 & 7520

4700 & 7520

4400 Welding, Brazing, Defect Removal and Installation

4200 & 4300 through 93A & 4170

4120, 4200,4300 & 4400 IWB-4200

4120, 4200 & 4300 IWB-4200

4500 Examination and Test 4530 Preservice Inspection and Testing 4540 Pressure Testing 4600 Alternative Welding Methods

4700 &4800 4820

4120, 4200,4300 & 4400 and IWB-4200 88A to 89A 4600 & 4700 4600 & 7530

4400 & 4500 4500 & 7530

4400 & 4500 4500 & 7530

4700 4500

4700 4500

4400 IWB-4300

4400 IWB-4300

A-6

1981 Winter Addenda through 1983 Summer Addenda 4110 &7110 7400

4130


tn

Seal weld

0.77 tn Root crack

r

Design Dimensions

0.77 tn Seal weld

As Welded Appearance

Root Crack

tn

Seal weld Seal weld Toe crack

0.77 tn r

0.77 tn

Toe Crack Figure 1. Socket Weld Weld Reinforcement Dimensions. The right side of the figures shows shows the design dimensions while the left side shows the the as-welded appearance. The final surface of of the overlay may be left in the as-welded condition


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1003165

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Assessment of Socket Weld Integrity in Pipings (2)

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