Information Notice 1992-68, Potentially Substandard Slip-On, Welding Neck, and Blind Flanges

Potentially Substandard Slip-On, Welding Neck, and Blind Flanges

ML031210730
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	09/10/1992
From:	Rossi C E Office of Nuclear Reactor Regulation
To:
References
IN-92-068, NUDOCS 9209030274
Download: ML031210730 (10)

UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555September 10, 1992NRC INFORMATION NOTICE 92-68: POTENTIALLY SUBSTANDARD SLIP-ON, WELDING NECK,AND BLIND FLANGES

Addressees

All holders of operating licenses or construction permits for nuclear powerreactors.PurDoseThe U.S. Nuclear Regulatory Commission (NRC) is issuing this informationnotice to alert licensees to problems with potentially substandard slip-on,welding neck, and blind flanges. It is expected that recipients will reviewthis information for applicability to their facilities and consider actions,as appropriate, to avoid similar problems. However, suggestions contained inthis information notice are not NRC requirements; therefore, no specificaction or written response is required.

Description of Circumstances

On July 9, 1992, the NRC staff met with a representative of The National Boardof Boiler and Pressure Vessel Inspectors (Board) to discuss the Board'sinvestigation of problems associated with flanges that originated from thePeople's Republic of China. The Board has received numerous reports offlanges marked "China" that contain cracks, inclusions, and slugged weldrepairs, and that were constructed from two pieces of material.The suspect China flanges were sold to U.S. suppliers through several tradingcompanies. Three of the trading companies identified were: BilliongoldCompany Limited of Hong Kong, Tain Gong Company, and Shanxi Province OverseasTrading Corporation. The suspect flanges were marked as forgings thatcomplied with the requirements of the American Society for Testing andMaterials (ASTM) Standard A-105, "Specification for Forgings, Carbon Steel,for Piping Components," and the American National Standards Institute (ANSI)Standard B16.5, "Dimensional Standards for Steel Pipe Flanges and FlangedFittings." However, the suspect flanges were manufactured with ring-insertswelded to the inside diameter of the flange and the outer surfaces weremachined. Consequently, a visual inspection would not detect either thewelding or the two-piece construction. Other flanges were found with sluggedweld repairs to the flange hub and still others failed to meet the materialspecification requirements for thermal treatment, mechanical properties, orchemistry.9209030274 PD P. TE IN 92-68September 10, 1992 DiscussionThe Board determined that one Chinese flange manufacturer, of the severalknown factories that supply the U.S., shipped more than 110 tons ofASTM A-105, ANSI B16, China flanges to this country. The Board stated thatover 7,000 flanges are being removed from refineries and petro-chemical plantsas a result of failures that occurred during welding, bolting, and hydrostaticand pre-operational testing. The Virginia Electric and Power Company informedNRC staff that China flanges are installed in two of its fossil power plantsand others are in its warehouse. At the time of discussion, Virginia Powerhad not determined whether any suspect China flanges are installed in itsnuclear power plants.The NRC does not have evidence that any suspect China flanges have beeninstalled in U.S. nuclear power plants. However, specific examples anddiscussions of the problems are attached for information.A potentially substandard "China" flange can pass between two or moredistributors before reaching the end-user facility. A nuclear power plantcould buy a commercial grade China flange from a distributor to dedicate theflange for safety-related use, or safety-related components or subassembliesthat contain China flanges could be supplied by licensee-approvedmanufacturers or fabricators. Establishing and verifying procedures to traceprocured equipment and material to the original manufacturer or mill is animportant prerequisite to inspecting and testing during the dedicationprocess. It is possible for a licensee to install potentially substandard ordefective equipment or material if it does not adequately verify that theproduct can be traced to the original manufacturer.This information notice requires no specific action or written response. Ifyou have any questions about this matter, please contact the technical contactlisted below, one of the Board representatives listed on the attachments, orthe appropriate Nuclear Reactor Regulation (NRR) project manager.I-Cha4rles E. ROssi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical contact: Steven M. Matthews, NRR(301) 504-3191

Attachments:

1. 1992 Board article, "Failure Analysis of a Slip-On Flange."2. Selected 1992 Board "NBBInfdletters."3. List of Recently Issued NRC Information Notices Attachment 1 -'IN 92-68September 10, 1992 .FAILUREANALYSISOF ASLI P-ONFLANGEThe installation of a 14 "slip-onflange in a pipeline was recentlywitnessed by Al Justin, chiefinspector for the State of Minne-sota. Tieflange originally had a14-3/4' inside diameter, whichwas reduced by welding a 3/4"ring and machine welding. The LII#ring, however, separatedfrom thelflange, giving the appearance of a Figure 1 Gasket side of flange.crack. Theflange is reported tohave been manufactured in the People's Republic of China.Several such flanges have been reported in thefield. All individuals in theindustry should be on the alertfor theseflanges.The following is a report by Columbus Metallurgical Services, Inc. on thefailure analysis of a slip-on flange.A 'cracked" 14" diameter slip-on flange was non-destructively inspected by usingmagnetic particle, dye penetrant and ultrasonic test methods. The flange was alsochecked for material chemical analysis and macro and microstructure. On the basis ofthe results and observations reported, the following conclusion is drawn:The subject slip-on flange is not an integral forging or a casting. It has beenfabricated by welding and machining a ring insert within a large diameterflange. The flange "cracked" because the welds between the flange and theinsert were inadequate to withstand the bolting pressures.# .w--.e.<t- ^. A. .Figure 2: A close-up of thegasket side showing the'crack indication.

BACKGROUND

The "cracked" slip-on flange was received by Columbus MetallurgicalServices, Inc. in one piece. It had two diametrically opposite crackslocated on pipe and gasket sides. It has been reported that se% eralsuch flanges are in the field. The subject flange has the followingengraved markings on the outside diameter (OD):"14 300 SO RF B16.5 A105 848 CHINA 02F"To identify the cause of the failure it was planned to perform dyepenetrant, dry magnetic particle, ultrasonic and radiographic tests onthe subject flang Attachment 1IN 92-68September 10, 1992 NON-DEsTRUCTIVE TESTSFirst, the flange was UT tested from the _ _ ;OD. The indications were ratherpuzzling because the reflections wereconsistently from a cylindrical surfaceabout 3.75" from the OD. A dry mag- -netic particle examination confirmedthat the cracks extended more or lesscontinuously in a circular path. The 7 A -NDT examination was concluded with [ 'dye penetrant tests as shown in the H i --photographs in Figures 1 through 4. It Figure 3: Pipe side of flange.was quite evident that the flange wasnot a single piece component. A large inside diameter (ID) flange was reduced to a 14"ID unit by welding a 0.75" thick ring. The welding faces had been machined.CHEMICAL ANALYSES AND METALLOGRAPHYThe flange was sectioned into four pieces to obtain specimens for chemistry, as well asfor macro and microscopic examination. The original engraved markings have beenretained on one of the segments. The chemical analyses are as follows:C Mn P S Si Cu Sn Ni Cr Mo Al VMain Flange Steel.23 .62 .024 .038 .24 .27 .016 .094 .079 .026 .006 .003Welded Insert Steel.26 1.02 .017 .039 .28 .063 .003 .050 .046 .032 .008 .000ANSI/ASTM A 105.35 .60-1.05 .040 .050 .35 (listed for reference only)_7 Figure4: A 5Figure : A~~-close-up of E L A ,, , *_ macro ot, -the pipe a raial__ side section.W ~ showing E~ethe 4 5 Hl'crock-. 1 :mi Eute Attachment IIN 92-68September 10, 1992 Figure 5 shows the radial macro sectionof the flange. Note the insert ringwelded to the main flange. Whenanother similar piece was further sec-tioned to retrieve specimens formounting and polishing, the insertseparated from the main flange. Thegeneral microstructure (ferritic-pearlitic)at 25X (Nital etch) is shown in Figure 6.ROCKWELL HARDNESS TESTMain Flange:70 HRBInsert:78 HRB72,69,70 HRB Ave =76,78,80 HRB Ave =Figure 6: Photo showing generalmicrostructure in the main flange (lowerhalf). insert (upper half) and weld metal (leftedge). 25X. Nital etch.No further work was deemed necessarvOBULLETIN/WINTER 1992 Attachment 2IN 92-68September 10, 1992 VOLUME I -NUMBER 16 -3/27/92Alert Continues for Flanges from ChinaThe Winter 1992 National Board Bullefinincluded an article regarding a seriousproblem found to exist on 14" slip-on,raised-face flanges.Since publication, NBBI has learned theproblem described is only one of manyassociated with flanges from the PeoplesRepublic of China.NBBI has been provided with a lab reportfor a 4" weld neck flange SA-105N B16-5with a BHN (Brinell Hardness Number) ofup to 500. Also, normalizing and chemis-try requirements do not meet SA-105requirements.These flanges have been reported to havecracks and other surface discontinuitiesthat might make them unfit for service. Inaddition, there have been reports thatsome flanges do not meet thicknessrequirements. NBBI also has been advisedthrough reinspection reports that someflanges may not bear the markings re-quired by the ANSI B16 specification,although they do bear the B16 mark.NBBI advises double-checking all flangeswith the marking "China," especiallybefore these flanges are placed in service.Certainly, flanges that have visible surfacediscontinuities or incomplete markingsmay be easy to see. But the machinedsurfaces of welded flanges can only bedetected through a volumetric form ofNDE. The failure to meet heat treat,mechanical or chemical requirements ofthe specifications can only be verifiedthrough metallurgic examination. .This update is being distributed in theinterest of public safety. Future updateswill be published as more facts are learned.Further questions or concerns should bedirected to A.M. 'Doc" Matthews, Jr. orR.D. Schueler, Jr. at National Board head-quarter \-_aAttachment 2 -IN 92-68September 10, 1992 NBBInfoletr/VOLUME I -NUMNER 17- 5/1/92Number of Suspect Flanges Growing atAlarming RateThe National Board continues to receivereports of several different types offlanges, ranging in sizes from 2 " to 20*and marked 'China," that do not appearto be in accordance with ANSI B16 asmarkings.As the number of suspect flanges contin-ues to grow, so does the different types ofproblems related to these flanges.To date, over 7,000 have been removedfrom service, including 1,600 recentlydiscovered in a newly-installed pipeline.An injunction has been ordered to ceasework on the pipeline until the flangeproblem has been resolved. The remain-ing 5,200+ flanges have been foundmostly in refineries.The president of the China Association ofBoiler and Pressure Vessel Inspection,Center of Boiler & Pressure Vessel Inspec-tion & Research of the Ministry of Labour,P.R.C., Wang Hannuo, has agreed to meetwith National Board Assistant Director ofInspections John McLouglin, late in Mayin Bejing to discuss the problem.NBBI continues to advise double-checkingall flanges with the marking China,'especially before these flanges are placedin service.Flanges that have visible surfacediscontinuities or incomplete markingsmay be easy to see. But the machinedsurfaces of welded flanges can only bedetected through a volumetric form ofNDE. The failure to meet heat treat,mechanical or chemical requirements ofthe specifications can only be verifiedthrough metallurgic examination.NBBI will continue to publish updates asinformation is learned. This update isdistributed in the interest of public safety.Further questions or concerns should bedirected to A.M. 'Doc" Matthews, Jr. orR.D. Schueler, Jr. at National Boardheadquartersfl Attachment 2 ..IN 92-68September 10, 1992 VOLUME I -NUMBER 18 -JUNE 1992etterFlange Update: McLoughlin Meets ChineseBoiler/Pressure Vessel OfficialsJohn D. McLoughlin, assistant director ofInspections,metwithseveral agendesof theChinese government during his recent visitto the Peoples Republic of China. The visitwas to discuss problems with flanges mnanu-factured in China (and distributed to theUS.).Two meetings were held in Beijing.On May 28, 1992, McLoughlin met withofficials of the Center of Boilerand PressureVessel Inspection and Research, as well asrepresentatives of Sha5ad Prvince Over-seas Trading Corporation, Tian Gong Com-pany. and Oine Xinang Nan Xi U FlareCompany.Mr. McLoughlin learned that Ding XinangNan Xi Li has shipped seven to eight con-tainers (each with 17 tons of various typesand sizes of flanges) to the US. thmugbwhat is believed to be Tacksonville, Florid&ShipptngwasreportedlyprovidedbyShanxiProvince, Tlan Gong and Billiongold (aHong Kong trader with Beijing offices).Mr. Yang Li Min of Shanxi Province Over-seas Trading Corporation reported that thebase material for these flanges was 25 MNand possibly 16 MN (both Chinese forgingspecifications) and not the A105 identifiedon both the flanges and material test report.It was stated by Mr. Yang U Min that manu-facturing identification on the flanges wasspecified by Billiongold (the Hong Kongtrader) and not the flange manufacturer.McLoughlin by Mr. Su Rung ji, vice premiieof China. Mr. McLoughlin met with Mr.Zheng You Mel, director of the ReceptionBureau, State Council, PRIC, Ms. Fan JiaNian, assistant director of the Reception Bu-reau, and several members of the Center ofBoiler and Pressure Vessel Inspection andResearch (representing the Ministry of La-bor). CBPV[R has been assisting the Na-tional Board in its investigationThe director of the Reception Bureau wasgivencopiesofinformationaccnunulatedaur-ing the course of Mr. McLoughlin's investi-gation and provided witha briefexplanationof the documents and the significance ofeach.Mr. Zheng You Mei reported that Mr. SuRung ji has a great interest in the flangesituation. He said the government appreci-ated the information provided by the Na-tional Board. Mr. Zheng You Mei also saidthat a complete report of the meeting wouldbe provided to Mr. Su Rung i.The etng concluded after Mr. McLoughlnprovided Mr. Zheng You Mei with recom-mrendations on steps the government couldtake to assure that steel mills and forgingmakers produce material and flanges thatmeet ASTM and ANSI specfications. TheNational Board will be advised when or ifthese recommnenda tions w-i be implxemnted.Upon his return to the US., Mr. McLoughlinreceived thelaboratoryresults of blind flangeand slip on flange tests that were orderedprior to his departure. Results of these testsare as follows:A scnd meeting was arranged for M Attachment 2 -PIN 92-68September 10, 1992 NBBIfoletterivowUmg 1 -NUMUER is-Jums 1992Flanges continued1.Blind flange withanidentific of'PP` and-ked A1O is reported to be aplatemate-riaL2Slip on flange with an identifier of USC orUlSIO and a heat #1406 contains sluggedweld repairs. The W weld repair indicatorrequired by AIOS Is not stapTed on theflange. The chemistry does not eet A105.The mill report does not indicate any type ofheat treat even though the flange is marked -AIO5N and has also been weld repaired. 'Finally, photo micographs indicate plate \ \materiaL The flange makers name is Shou '_RolesGang Machinery Engineering Company.According to Mr. McLoughlin:This office M%* NBIonfdLtt? is pubUahed monthly byAccordinghecNationalzB 3d of &oilr and Prewuirthas probably accomplished all it can at this V Inp , 10 Crue Ave=ue,point, with the resources available. The Cohlubus, Ohio 4329,(614) 888-2DNational Board will publish a spedil editionof Xte National Boad Bulletin that will ad- D.I. MCDonaLdress this problems Hopefully, we will be Exsputivr Drcwable to report steps the Chinese government A.KM Doe Matthews, Jr.are taking to insure that their flange prod. ASS3StWt EpAy= Dirctarucs meet spedficadon.e PD. Bnreut A,Diractof WUMMhotISThe National Board will be providing vanr- sC Nbcosous appropriate agencies of the US. govern-ment with information it has acquiredthrough the investigation processO I IAttachment 3IN 92-68September 10, 992LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to92-67Deficiency in DesignModifications to Ad-dress Failures ofHiller Actuators UponA Gradual Loss ofAir Pressure09/10/92All holders of OLs or CPsfor nuclear power reactors.92-66Access Denied to NRCInspectors at Five StarProducts, Inc. andConstruction ProductsResearch, Fairfield,Connecticut09/01/92All holdersfor nuclearand all reciNUREG-0040,tractor andtion StatusBook).of OLs or CPspower reactorspients of"Licensee, Con-Vendor Inspec-Report" (White92-6592-6492-6392-6292-6192-60Safety System ProblemsCaused by ModificationsThat Were Not AdequatelyReviewed and TestedNozzl eon LowReliefRing SettingsPressure Water-ValvesCracked Insulators inASL Dry Type TransformersManufactured by Westing-house Electric CorporationEmergency ResponseInformation Require-ments for RadioactiveMaterial ShipmentsLoss of High HeadSafety InjectionValve Stem FailureCaused by Embrittlement09/03/9208/28/9208/26/9208/24/9208/20/9208/20/92All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All U.S. Nuclear RegulatoryCommission licensees.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor pressurized waterreactors (PWRs).OL = Operating LicenseCP = Construction Permit