Information Notice 1992-68, Potentially Substandard Slip-On, Welding Neck, and Blind Flanges: Difference between revisions
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| issue date = 09/10/1992 | | issue date = 09/10/1992 | ||
| title = Potentially Substandard Slip-On, Welding Neck, and Blind Flanges | | title = Potentially Substandard Slip-On, Welding Neck, and Blind Flanges | ||
| author name = Rossi C | | author name = Rossi C | ||
| author affiliation = NRC/NRR | | author affiliation = NRC/NRR | ||
| addressee name = | | addressee name = | ||
Line 13: | Line 13: | ||
| document type = NRC Information Notice | | document type = NRC Information Notice | ||
| page count = 10 | | page count = 10 | ||
}} | }} | ||
{{#Wiki_filter:UNITED | {{#Wiki_filter:UNITED STATES | ||
NUCLEAR REGULATORY COMMISSION | |||
OFFICE OF NUCLEAR REACTOR REGULATION | |||
WASHINGTON, D.C. 20555 September 10, 1992 NRC INFORMATION NOTICE 92-68: POTENTIALLY SUBSTANDARD SLIP-ON, WELDING NECK, | |||
AND BLIND FLANGES | |||
==Addressees== | ==Addressees== | ||
All holders of operating licenses or construction permits for nuclear | All holders of operating licenses or construction permits for nuclear power | ||
reactors. | |||
PurDose | |||
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information | |||
notice to alert licensees to problems with potentially substandard slip-on, welding neck, and blind flanges. It is expected that recipients will review | |||
this information for applicability to their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in | |||
this information notice are not NRC requirements; therefore, no specific | |||
action or written response is required. | |||
==Description of Circumstances== | ==Description of Circumstances== | ||
On July 9, 1992, the NRC staff met with a representative of The National | On July 9, 1992, the NRC staff met with a representative of The National Board | ||
of Boiler and Pressure Vessel Inspectors (Board) to discuss the Board's | |||
investigation of problems associated with flanges that originated from the | |||
People's Republic of China. The Board has received numerous reports of | |||
flanges marked "China" that contain cracks, inclusions, and slugged weld | |||
repairs, and that were constructed from two pieces of material. | |||
The suspect China flanges were sold to U.S. suppliers through several trading | |||
companies. Three of the trading companies identified were: Billiongold | |||
Company Limited of Hong Kong, Tain Gong Company, and Shanxi Province Overseas | |||
Trading Corporation. The suspect flanges were marked as forgings that | |||
complied with the requirements of the American Society for Testing and | |||
Materials (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 Flanged | |||
Fittings." However, the suspect flanges were manufactured with ring-inserts | |||
welded to the inside diameter of the flange and the outer surfaces were | |||
machined. Consequently, a visual inspection would not detect either the | |||
welding or the two-piece construction. Other flanges were found with slugged | |||
weld repairs to the flange hub and still others failed to meet the material | |||
specification requirements for thermal treatment, mechanical properties, or | |||
chemistry. | |||
9209030274 PDP. TE | |||
IN 92-68 September 10, 1992 Discussion | |||
The Board determined that one Chinese flange manufacturer, of the several | |||
known factories that supply the U.S., shipped more than 110 tons of | |||
ASTM A-105, ANSI B16, China flanges to this country. The Board stated that | |||
over 7,000 flanges are being removed from refineries and petro-chemical plants | |||
as a result of failures that occurred during welding, bolting, and hydrostatic | |||
and pre-operational testing. The Virginia Electric and Power Company informed | |||
NRC staff that China flanges are installed in two of its fossil power plants | |||
and others are in its warehouse. At the time of discussion, Virginia Power | |||
had not determined whether any suspect China flanges are installed in its | |||
nuclear power plants. | |||
The NRC does not have evidence that any suspect China flanges have been | |||
installed in U.S. nuclear power plants. However, specific examples and | |||
discussions of the problems are attached for information. | |||
A potentially substandard "China" flange can pass between two or more | |||
distributors before reaching the end-user facility. A nuclear power plant | |||
could buy a commercial grade China flange from a distributor to dedicate the | |||
flange for safety-related use, or safety-related components or subassemblies | |||
that contain China flanges could be supplied by licensee-approved | |||
manufacturers or fabricators. Establishing and verifying procedures to trace | |||
procured equipment and material to the original manufacturer or mill is an | |||
important prerequisite to inspecting and testing during the dedication | |||
process. It is possible for a licensee to install potentially substandard or | |||
defective equipment or material if it does not adequately verify that the | |||
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- | |||
product can be traced to the original manufacturer. | |||
This information notice requires no specific action or written response. If | |||
you have any questions about this matter, please contact the technical contact | |||
listed below, one of the Board representatives listed on the attachments, or | |||
the appropriate Nuclear Reactor Regulation (NRR) project manager. | |||
I- | |||
Cha4rles E.ROssi, Director | |||
Division of Operational Events Assessment | |||
Office of Nuclear Reactor Regulation | |||
Technical 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 92-68 September 10, 1992 . | |||
The installationof a 14 "slip-on | |||
flange in a pipeline was recently | |||
witnessed by Al Justin, chief | |||
inspectorfor the State of Minne- sota. Tieflange originallyhad a | |||
14-3/4' inside diameter, which | |||
was reduced by welding a 3/4" | |||
ringand machine welding. The | |||
ring, however, separatedfromthel | |||
LII# | |||
flange, giving the appearanceof a Figure 1 Gasket side of flange. | |||
FAILURE crack. Theflange is reported to | |||
ANALYSIS have been manufactured in the People's Republic of China. | |||
OF A Several such flanges have been reported in thefield. All individuals in the | |||
SLI P-ON industry should be on the alertfor theseflanges. | |||
FLANGE The following is a report by Columbus MetallurgicalServices, Inc. on the | |||
failure analysis of a slip-on flange. | |||
A 'cracked" 14" diameter slip-on flange was non-destructively inspected by using | |||
magnetic particle, dye penetrant and ultrasonic test methods. The flange was also | |||
checked for material chemical analysis and macro and microstructure. On the basis of | |||
the results and observations reported, the following conclusion is drawn: | |||
The subject slip-on flange is not an integral forging or a casting. It has been | |||
fabricated by welding and machining a ring insert within a large diameter | |||
flange. The flange "cracked" because the welds between the flange and the | |||
insert were inadequate to withstand the bolting pressures. | |||
==BACKGROUND== | ==BACKGROUND== | ||
The "cracked" slip-on flange was received by Columbus | The "cracked" slip-on flange was received by Columbus Metallurgical | ||
Services, Inc. in one piece. It had two diametrically opposite cracks | |||
located on pipe and gasket sides. It has been reported that se%eral | |||
#. w--.e.<t- ^. A. . | |||
such flanges are in the field. The subject flange has the following | |||
engraved 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 dye | |||
penetrant, dry magnetic particle, ultrasonic and radiographic tests on | |||
Figure 2: A close-up of the the subject flange. | |||
gasket side showing the | |||
'crack indication. | |||
Attachment 1 IN 92-68 September 10, 1992 NON-DEsTRUCTIVE TESTS | |||
First, the flange was UT tested from the _ _ ; | |||
OD. The indications were rather | |||
puzzling because the reflections were | |||
consistently from a cylindrical surface | |||
about 3.75" from the OD. A dry mag- - | |||
netic particle examination confirmed | |||
that the cracks extended more or less | |||
continuously in a circular path. The A - 7 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 was | |||
not 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 METALLOGRAPHY | |||
The flange was sectioned into four pieces to obtain specimens for chemistry, as well as | |||
for macro and microscopic examination. The original engraved markings have been | |||
retained on one of the segments. The chemical analyses are as follows: | |||
C Mn P S Si Cu Sn Ni Cr Mo Al V | |||
Main Flange Steel | |||
.23 .62 .024 .038 .24 .27 .016 .094 .079 .026 Eutes. | |||
.006 .003 Welded Insert Steel | |||
.26 1.02 .017 .039 .28 .063 .003 .050 .046 .032 .008 .000 | |||
ANSI/ASTM A 105 | |||
.35 .60-1.05 .040 .050 .35 (listed for reference only) | |||
_7 Figure4: A 5Figure | |||
: A | |||
~~-close-up of A ,, , *_ E L macro ot | |||
, - the pipe a raial | |||
__ side section. | |||
W ~ showing E~e | |||
the 4 5 Hl | |||
'crock-.: 1 mi | |||
Attachment I | |||
IN 92-68 September 10, 1992 Figure 5 shows the radial macro section | |||
of the flange. Note the insert ring | |||
welded to the main flange. When | |||
another similar piece was further sec- tioned to retrieve specimens for | |||
mounting and polishing, the insert | |||
separated from the main flange. The | |||
general microstructure (ferritic-pearlitic) | |||
at 25X (Nital etch) is shown in Figure 6. | |||
===ROCKWELL HARDNESS TEST=== | |||
Main Flange: 72,69,70 HRB Ave = Figure 6: Photo showing general | |||
70 HRB microstructure in the main flange (lower | |||
76,78,80 HRB Ave = half). insert (upper half) and weld metal (left | |||
Insert: edge). 25X. Nital etch. | |||
78 HRB | |||
===No further work was deemed necessarvO=== | |||
BULLETIN/WINTER 1992 | |||
Attachment 2 IN 92-68 September 10, 1992 VOLUME I - NUMBER 16 - 3/27/92 | |||
===Alert Continues for Flanges from China=== | |||
The Winter 1992 NationalBoard Bullefin quired by the ANSI B16 specification, included an article regarding a serious although they do bear the B16 mark. | |||
problem found to exist on 14" slip-on, raised-face flanges. NBBI advises double-checking all flanges | |||
with the marking "China," especially | |||
Since publication, NBBI has learned the before these flanges are placed in service. | |||
problem described is only one of many | |||
associated with flanges from the Peoples Certainly, flanges that have visible surface | |||
Republic of China. discontinuities or incomplete markings | |||
may be easy to see. But the machined | |||
NBBI has been provided with a lab report surfaces of welded flanges can only be | |||
for a 4" weld neck flange SA-105N B16-5 detected through a volumetric form of | |||
with a BHN (Brinell Hardness Number) of NDE. The failure to meet heat treat, up to 500. Also, normalizing and chemis- mechanical or chemical requirements of | |||
try requirements do not meet SA-105 the specifications can only be verified | |||
requirements. through metallurgic examination. . | |||
These flanges have been reported to have This update is being distributed in the | |||
cracks and other surface discontinuities interest of public safety. Future updates | |||
that might make them unfit for service. In will be published as more facts are learned. | |||
addition, there have been reports that | |||
some flanges do not meet thickness Further questions or concerns should be | |||
requirements. NBBI also has been advised directed to A.M. 'Doc" Matthews, Jr. or | |||
through reinspection reports that some R.D. Schueler, Jr. at National Board head- flanges may not bear the markings re- quarters. | |||
\-_a | |||
Attachment 2 - | |||
IN 92-68 September 10, 1992 NBBInfoletr/VOLUME I- NUMNER 17- 5/1/92 Number of Suspect Flanges Growing at | |||
Alarming Rate | |||
The National Board continues to receive Inspections John McLouglin, late in May | |||
reports of several different types of in Bejing to discuss the problem. | |||
flanges, ranging in sizes from 2 " to 20* | |||
and marked 'China," that do not appear NBBI continues to advise double-checking | |||
to be in accordance with ANSI B16 as all flanges with the marking China,' | |||
markings. especially before these flanges are placed | |||
in service. | |||
As the number of suspect flanges contin- ues to grow, so does the different types of Flanges that have visible surface | |||
problems related to these flanges. discontinuities or incomplete markings | |||
may be easy to see. But the machined | |||
To date, over 7,000 have been removed surfaces of welded flanges can only be | |||
from service, including 1,600 recently detected through a volumetric form of | |||
discovered in a newly-installed pipeline. NDE. The failure to meet heat treat, An injunction has been ordered to cease mechanical or chemical requirements of | |||
work on the pipeline until the flange the specifications can only be verified | |||
problem has been resolved. The remain- through metallurgic examination. | |||
ing 5,200+ flanges have been found | |||
mostly in refineries. NBBI will continue to publish updates as | |||
information is learned. This update is | |||
The president of the China Association of distributed in the interest of public safety. | |||
Boiler and Pressure Vessel Inspection, Center of Boiler & Pressure Vessel Inspec- Further questions or concerns should be | |||
tion & Research of the Ministry of Labour, directed to A.M. 'Doc" Matthews, Jr. or | |||
P.R.C., Wang Hannuo, has agreed to meet R.D. Schueler, Jr. at National Board | |||
with National Board Assistant Director of headquartersfl | |||
Attachment 2 .. | |||
IN 92-68 September 10, 1992 etter VOLUME I - NUMBER 18 - JUNE 1992 Flange Update: McLoughlin Meets Chinese | |||
Boiler/Pressure Vessel Officials | |||
John D. McLoughlin, assistant director of McLoughlin by Mr. Su Rung ji, vice premiie | |||
Inspections,metwithseveral agendesof the of China. Mr. McLoughlin met with Mr. | |||
Chinese government during his recent visit Zheng You Mel, director of the Reception | |||
to the Peoples Republic of China. The visit Bureau, State Council, PRIC, Ms. Fan Jia | |||
was to discuss problems with flanges mnanu- Nian, assistant director of the Reception Bu- factured in China (and distributed to the reau, and several members of the Center of | |||
US.). Boiler and Pressure Vessel Inspection and | |||
Research (representing the Ministry of La- Two meetings were held in Beijing. bor). CBPV[R has been assisting the Na- tional Board in its investigation | |||
===On May 28, 1992, McLoughlin met with=== | |||
officials of the Center of Boilerand Pressure The director of the Reception Bureau was | |||
Vessel Inspection and Research, as well as givencopiesofinformationaccnunulatedaur- representatives of Sha5ad Prvince Over- ing the course of Mr. McLoughlin's investi- seas Trading Corporation, Tian Gong Com- gation and provided witha briefexplanation | |||
pany. and Oine Xinang Nan Xi U Flare of the documents and the significance of | |||
Company. each. | |||
Mr. McLoughlin learned that Ding Xinang Mr. Zheng You Mei reported that Mr. Su | |||
Nan Xi Li has shipped seven to eight con- Rung ji has a great interest in the flange | |||
tainers (each with 17 tons of various types situation. He said the government appreci- and sizes of flanges) to the US. thmugb ated the information provided by the Na- what is believed to be Tacksonville, Florid& tional Board. Mr. Zheng You Mei also said | |||
ShipptngwasreportedlyprovidedbyShanxi that a complete report of the meeting would | |||
Province, Tlan Gong and Billiongold (a be provided to Mr. Su Rung i. | |||
Hong Kong trader with Beijing offices). | |||
The etng concluded after Mr. McLoughln | |||
Mr. Yang Li Min of Shanxi Province Over- provided Mr. Zheng You Mei with recom- seas Trading Corporation reported that the mrendations on steps the government could | |||
base material for these flanges was 25 MN take to assure that steel mills and forging | |||
and possibly 16 MN (both Chinese forging makers produce material and flanges that | |||
specifications) and not the A105 identified meet ASTM and ANSI specfications. The | |||
on both the flanges and material test report. National Board will be advised when or if | |||
these recommnenda tions w-i be implxemnted. | |||
It was stated by Mr. Yang U Min that manu- facturing identification on the flanges was Upon his return to the US., Mr. McLoughlin | |||
specified by Billiongold (the Hong Kong received thelaboratoryresults of blind flange | |||
trader) and not the flange manufacturer. and slip on flange tests that were ordered | |||
prior to his departure. Results of these tests | |||
A scnd meeting was arranged for Mr. are as follows: | |||
Attachment 2 -P | |||
IN 92-68 September 10, 1992 NBBIfoletterivowUmg 1 -NUMUER is-Jums 1992 | |||
===Flanges continued=== | |||
1.Blind flange withanidentific of'PP` and | |||
-ked A1O is reported to be aplatemate- riaL | |||
2Slip on flange with an identifier of USC or | |||
UlSIO and a heat #1406 contains slugged | |||
weld repairs. The W weld repair indicator | |||
required by AIOS Is not stapTed on the | |||
flange. The chemistry does not eet A105. | |||
===The mill report does not indicate any type of=== | |||
heat 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 '_Roles | |||
Gang Machinery Engineering Company. | |||
M%* NBIonfdLtt? ispubUahed monthly by | |||
According to Mr. McLoughlin:This office 3d of &oilrand Prewuirt | |||
AccordinghecNationalzB V Inp , 10 Crue Ave=ue, has probably accomplished all it can at this | |||
point, with the resources available. The Cohlubus, Ohio 4329,(614) 888-2D | |||
National Board will publish a spedil edition | |||
of Xte National Boad Bulletin that will ad- D.I.MCDonaL | |||
dress this problems Hopefully, we will be Exsputivr Drcw | |||
able to report steps the Chinese government A.KM Doe Matthews, Jr. | |||
are taking to insure that their flange prod. ASS3StWt EpAy= Dirctar | |||
ucs meet spedficadon.e PD. Bnreut A, | |||
Diractof WUMMhotIS | |||
The National Board will be providing vanr- sC Nbcos | |||
ous appropriate agencies of the US. govern- ment with information it has acquired | |||
through the investigation processO | |||
I I | |||
Attachment 3 IN 92-68 September 10, 1992 LIST OF RECENTLY ISSUED | |||
NRC INFORMATION NOTICES | |||
Information Date of | |||
Notice No. Subject Issuance Issued to | |||
92-67 Deficiency in Design 09/10/92 All holders of OLs or CPs | |||
Modifications to Ad- for nuclear power reactors. | |||
dress Failures of | |||
Hiller Actuators Upon | |||
A Gradual Loss of | |||
Air Pressure | |||
92-66 Access Denied to NRC 09/01/92 All holders of OLs or CPs | |||
Inspectors at Five Star for nuclear power reactors | |||
Products, Inc. and and all reci pients of | |||
Construction Products NUREG-0040, "Licensee, Con- Research, Fairfield, tractor and Vendor Inspec- Connecticut tion Status Report" (White | |||
Book). | |||
92-65 Safety System Problems 09/03/92 All holders of OLs or CPs | |||
Caused by Modifications for nuclear power reactors. | |||
That Were Not Adequately | |||
Reviewed and Tested | |||
92-64 Nozzl e Ring Settings 08/28/92 All holders of OLs or CPs | |||
on Low Pressure Water- for nuclear power reactors. | |||
Relief Valves | |||
92-63 Cracked Insulators in 08/26/92 All holders of OLs or CPs | |||
ASL Dry Type Transformers for nuclear power reactors. | |||
Manufactured by Westing- house Electric Corporation | |||
92-62 Emergency Response 08/24/92 All U.S. Nuclear Regulatory | |||
Information Require- Commission licensees. | |||
ments for Radioactive | |||
Material Shipments | |||
92-61 Loss of High Head 08/20/92 All holders of OLs or CPs | |||
Safety Injection for nuclear power reactors. | |||
92-60 Valve Stem Failure 08/20/92 All holders of OLs or CPs | |||
Caused by Embrittlement for pressurized water | |||
reactors (PWRs). | |||
OL = Operating License | |||
CP = Construction Permit}} | |||
{{Information notice-Nav}} | {{Information notice-Nav}} |
Latest revision as of 03:07, 24 November 2019
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555 September 10, 1992 NRC INFORMATION NOTICE 92-68: POTENTIALLY SUBSTANDARD SLIP-ON, WELDING NECK,
AND BLIND FLANGES
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
PurDose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert licensees to problems with potentially substandard slip-on, welding neck, and blind flanges. It is expected that recipients will review
this information for applicability to their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in
this information notice are not NRC requirements; therefore, no specific
action or written response is required.
Description of Circumstances
On July 9, 1992, the NRC staff met with a representative of The National Board
of Boiler and Pressure Vessel Inspectors (Board) to discuss the Board's
investigation of problems associated with flanges that originated from the
People's Republic of China. The Board has received numerous reports of
flanges marked "China" that contain cracks, inclusions, and slugged weld
repairs, and that were constructed from two pieces of material.
The suspect China flanges were sold to U.S. suppliers through several trading
companies. Three of the trading companies identified were: Billiongold
Company Limited of Hong Kong, Tain Gong Company, and Shanxi Province Overseas
Trading Corporation. The suspect flanges were marked as forgings that
complied with the requirements of the American Society for Testing and
Materials (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 Flanged
Fittings." However, the suspect flanges were manufactured with ring-inserts
welded to the inside diameter of the flange and the outer surfaces were
machined. Consequently, a visual inspection would not detect either the
welding or the two-piece construction. Other flanges were found with slugged
weld repairs to the flange hub and still others failed to meet the material
specification requirements for thermal treatment, mechanical properties, or
chemistry.
9209030274 PDP. TE
IN 92-68 September 10, 1992 Discussion
The Board determined that one Chinese flange manufacturer, of the several
known factories that supply the U.S., shipped more than 110 tons of
ASTM A-105, ANSI B16, China flanges to this country. The Board stated that
over 7,000 flanges are being removed from refineries and petro-chemical plants
as a result of failures that occurred during welding, bolting, and hydrostatic
and pre-operational testing. The Virginia Electric and Power Company informed
NRC staff that China flanges are installed in two of its fossil power plants
and others are in its warehouse. At the time of discussion, Virginia Power
had not determined whether any suspect China flanges are installed in its
nuclear power plants.
The NRC does not have evidence that any suspect China flanges have been
installed in U.S. nuclear power plants. However, specific examples and
discussions of the problems are attached for information.
A potentially substandard "China" flange can pass between two or more
distributors before reaching the end-user facility. A nuclear power plant
could buy a commercial grade China flange from a distributor to dedicate the
flange for safety-related use, or safety-related components or subassemblies
that contain China flanges could be supplied by licensee-approved
manufacturers or fabricators. Establishing and verifying procedures to trace
procured equipment and material to the original manufacturer or mill is an
important prerequisite to inspecting and testing during the dedication
process. It is possible for a licensee to install potentially substandard or
defective equipment or material if it does not adequately verify that the
product can be traced to the original manufacturer.
This information notice requires no specific action or written response. If
you have any questions about this matter, please contact the technical contact
listed below, one of the Board representatives listed on the attachments, or
the appropriate Nuclear Reactor Regulation (NRR) project manager.
I-
Cha4rles E.ROssi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical 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 92-68 September 10, 1992 .
The installationof a 14 "slip-on
flange in a pipeline was recently
witnessed by Al Justin, chief
inspectorfor the State of Minne- sota. Tieflange originallyhad a
14-3/4' inside diameter, which
was reduced by welding a 3/4"
ringand machine welding. The
ring, however, separatedfromthel
LII#
flange, giving the appearanceof a Figure 1 Gasket side of flange.
FAILURE crack. Theflange is reported to
ANALYSIS have been manufactured in the People's Republic of China.
OF A Several such flanges have been reported in thefield. All individuals in the
SLI P-ON industry should be on the alertfor theseflanges.
FLANGE The following is a report by Columbus MetallurgicalServices, Inc. on the
failure analysis of a slip-on flange.
A 'cracked" 14" diameter slip-on flange was non-destructively inspected by using
magnetic particle, dye penetrant and ultrasonic test methods. The flange was also
checked for material chemical analysis and macro and microstructure. On the basis of
the results and observations reported, the following conclusion is drawn:
The subject slip-on flange is not an integral forging or a casting. It has been
fabricated by welding and machining a ring insert within a large diameter
flange. The flange "cracked" because the welds between the flange and the
insert were inadequate to withstand the bolting pressures.
BACKGROUND
The "cracked" slip-on flange was received by Columbus Metallurgical
Services, Inc. in one piece. It had two diametrically opposite cracks
located on pipe and gasket sides. It has been reported that se%eral
- . w--.e.<t- ^. A. .
such flanges are in the field. The subject flange has the following
engraved 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 dye
penetrant, dry magnetic particle, ultrasonic and radiographic tests on
Figure 2: A close-up of the the subject flange.
gasket side showing the
'crack indication.
Attachment 1 IN 92-68 September 10, 1992 NON-DEsTRUCTIVE TESTS
First, the flange was UT tested from the _ _ ;
OD. The indications were rather
puzzling because the reflections were
consistently from a cylindrical surface
about 3.75" from the OD. A dry mag- -
netic particle examination confirmed
that the cracks extended more or less
continuously in a circular path. The A - 7 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 was
not 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 METALLOGRAPHY
The flange was sectioned into four pieces to obtain specimens for chemistry, as well as
for macro and microscopic examination. The original engraved markings have been
retained on one of the segments. The chemical analyses are as follows:
C Mn P S Si Cu Sn Ni Cr Mo Al V
Main Flange Steel
.23 .62 .024 .038 .24 .27 .016 .094 .079 .026 Eutes.
.006 .003 Welded Insert Steel
.26 1.02 .017 .039 .28 .063 .003 .050 .046 .032 .008 .000
ANSI/ASTM A 105
.35 .60-1.05 .040 .050 .35 (listed for reference only)
_7 Figure4: A 5Figure
- A
~~-close-up of A ,, , *_ E L macro ot
, - the pipe a raial
__ side section.
W ~ showing E~e
the 4 5 Hl
'crock-.: 1 mi
Attachment I
IN 92-68 September 10, 1992 Figure 5 shows the radial macro section
of the flange. Note the insert ring
welded to the main flange. When
another similar piece was further sec- tioned to retrieve specimens for
mounting and polishing, the insert
separated from the main flange. The
general microstructure (ferritic-pearlitic)
at 25X (Nital etch) is shown in Figure 6.
ROCKWELL HARDNESS TEST
Main Flange: 72,69,70 HRB Ave = Figure 6: Photo showing general
70 HRB microstructure in the main flange (lower
76,78,80 HRB Ave = half). insert (upper half) and weld metal (left
Insert: edge). 25X. Nital etch.
78 HRB
No further work was deemed necessarvO
BULLETIN/WINTER 1992
Attachment 2 IN 92-68 September 10, 1992 VOLUME I - NUMBER 16 - 3/27/92
Alert Continues for Flanges from China
The Winter 1992 NationalBoard Bullefin quired by the ANSI B16 specification, included an article regarding a serious although they do bear the B16 mark.
problem found to exist on 14" slip-on, raised-face flanges. NBBI advises double-checking all flanges
with the marking "China," especially
Since publication, NBBI has learned the before these flanges are placed in service.
problem described is only one of many
associated with flanges from the Peoples Certainly, flanges that have visible surface
Republic of China. discontinuities or incomplete markings
may be easy to see. But the machined
NBBI has been provided with a lab report surfaces of welded flanges can only be
for a 4" weld neck flange SA-105N B16-5 detected through a volumetric form of
with a BHN (Brinell Hardness Number) of NDE. The failure to meet heat treat, up to 500. Also, normalizing and chemis- mechanical or chemical requirements of
try requirements do not meet SA-105 the specifications can only be verified
requirements. through metallurgic examination. .
These flanges have been reported to have This update is being distributed in the
cracks and other surface discontinuities interest of public safety. Future updates
that might make them unfit for service. In will be published as more facts are learned.
addition, there have been reports that
some flanges do not meet thickness Further questions or concerns should be
requirements. NBBI also has been advised directed to A.M. 'Doc" Matthews, Jr. or
through reinspection reports that some R.D. Schueler, Jr. at National Board head- flanges may not bear the markings re- quarters.
\-_a
Attachment 2 -
IN 92-68 September 10, 1992 NBBInfoletr/VOLUME I- NUMNER 17- 5/1/92 Number of Suspect Flanges Growing at
Alarming Rate
The National Board continues to receive Inspections John McLouglin, late in May
reports of several different types of in Bejing to discuss the problem.
flanges, ranging in sizes from 2 " to 20*
and marked 'China," that do not appear NBBI continues to advise double-checking
to be in accordance with ANSI B16 as all flanges with the marking China,'
markings. especially before these flanges are placed
in service.
As the number of suspect flanges contin- ues to grow, so does the different types of Flanges that have visible surface
problems related to these flanges. discontinuities or incomplete markings
may be easy to see. But the machined
To date, over 7,000 have been removed surfaces of welded flanges can only be
from service, including 1,600 recently detected through a volumetric form of
discovered in a newly-installed pipeline. NDE. The failure to meet heat treat, An injunction has been ordered to cease mechanical or chemical requirements of
work on the pipeline until the flange the specifications can only be verified
problem has been resolved. The remain- through metallurgic examination.
ing 5,200+ flanges have been found
mostly in refineries. NBBI will continue to publish updates as
information is learned. This update is
The president of the China Association of distributed in the interest of public safety.
Boiler and Pressure Vessel Inspection, Center of Boiler & Pressure Vessel Inspec- Further questions or concerns should be
tion & Research of the Ministry of Labour, directed to A.M. 'Doc" Matthews, Jr. or
P.R.C., Wang Hannuo, has agreed to meet R.D. Schueler, Jr. at National Board
with National Board Assistant Director of headquartersfl
Attachment 2 ..
IN 92-68 September 10, 1992 etter VOLUME I - NUMBER 18 - JUNE 1992 Flange Update: McLoughlin Meets Chinese
Boiler/Pressure Vessel Officials
John D. McLoughlin, assistant director of McLoughlin by Mr. Su Rung ji, vice premiie
Inspections,metwithseveral agendesof the of China. Mr. McLoughlin met with Mr.
Chinese government during his recent visit Zheng You Mel, director of the Reception
to the Peoples Republic of China. The visit Bureau, State Council, PRIC, Ms. Fan Jia
was to discuss problems with flanges mnanu- Nian, assistant director of the Reception Bu- factured in China (and distributed to the reau, and several members of the Center of
US.). Boiler and Pressure Vessel Inspection and
Research (representing the Ministry of La- Two meetings were held in Beijing. bor). CBPV[R has been assisting the Na- tional Board in its investigation
On May 28, 1992, McLoughlin met with
officials of the Center of Boilerand Pressure The director of the Reception Bureau was
Vessel Inspection and Research, as well as givencopiesofinformationaccnunulatedaur- representatives of Sha5ad Prvince Over- ing the course of Mr. McLoughlin's investi- seas Trading Corporation, Tian Gong Com- gation and provided witha briefexplanation
pany. and Oine Xinang Nan Xi U Flare of the documents and the significance of
Company. each.
Mr. McLoughlin learned that Ding Xinang Mr. Zheng You Mei reported that Mr. Su
Nan Xi Li has shipped seven to eight con- Rung ji has a great interest in the flange
tainers (each with 17 tons of various types situation. He said the government appreci- and sizes of flanges) to the US. thmugb ated the information provided by the Na- what is believed to be Tacksonville, Florid& tional Board. Mr. Zheng You Mei also said
ShipptngwasreportedlyprovidedbyShanxi that a complete report of the meeting would
Province, Tlan Gong and Billiongold (a be provided to Mr. Su Rung i.
Hong Kong trader with Beijing offices).
The etng concluded after Mr. McLoughln
Mr. Yang Li Min of Shanxi Province Over- provided Mr. Zheng You Mei with recom- seas Trading Corporation reported that the mrendations on steps the government could
base material for these flanges was 25 MN take to assure that steel mills and forging
and possibly 16 MN (both Chinese forging makers produce material and flanges that
specifications) and not the A105 identified meet ASTM and ANSI specfications. The
on both the flanges and material test report. National Board will be advised when or if
these recommnenda tions w-i be implxemnted.
It was stated by Mr. Yang U Min that manu- facturing identification on the flanges was Upon his return to the US., Mr. McLoughlin
specified by Billiongold (the Hong Kong received thelaboratoryresults of blind flange
trader) and not the flange manufacturer. and slip on flange tests that were ordered
prior to his departure. Results of these tests
A scnd meeting was arranged for Mr. are as follows:
Attachment 2 -P
IN 92-68 September 10, 1992 NBBIfoletterivowUmg 1 -NUMUER is-Jums 1992
Flanges continued
1.Blind flange withanidentific of'PP` and
-ked A1O is reported to be aplatemate- riaL
2Slip on flange with an identifier of USC or
UlSIO and a heat #1406 contains slugged
weld repairs. The W weld repair indicator
required by AIOS Is not stapTed on the
flange. The chemistry does not eet A105.
The mill report does not indicate any type of
heat 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 '_Roles
Gang Machinery Engineering Company.
M%* NBIonfdLtt? ispubUahed monthly by
According to Mr. McLoughlin:This office 3d of &oilrand Prewuirt
AccordinghecNationalzB V Inp , 10 Crue Ave=ue, has probably accomplished all it can at this
point, with the resources available. The Cohlubus, Ohio 4329,(614) 888-2D
National Board will publish a spedil edition
of Xte National Boad Bulletin that will ad- D.I.MCDonaL
dress this problems Hopefully, we will be Exsputivr Drcw
able to report steps the Chinese government A.KM Doe Matthews, Jr.
are taking to insure that their flange prod. ASS3StWt EpAy= Dirctar
ucs meet spedficadon.e PD. Bnreut A,
Diractof WUMMhotIS
The National Board will be providing vanr- sC Nbcos
ous appropriate agencies of the US. govern- ment with information it has acquired
through the investigation processO
I I
Attachment 3 IN 92-68 September 10, 1992 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information Date of
Notice No. Subject Issuance Issued to
92-67 Deficiency in Design 09/10/92 All holders of OLs or CPs
Modifications to Ad- for nuclear power reactors.
dress Failures of
Hiller Actuators Upon
A Gradual Loss of
Air Pressure
92-66 Access Denied to NRC 09/01/92 All holders of OLs or CPs
Inspectors at Five Star for nuclear power reactors
Products, Inc. and and all reci pients of
Construction Products NUREG-0040, "Licensee, Con- Research, Fairfield, tractor and Vendor Inspec- Connecticut tion Status Report" (White
Book).
92-65 Safety System Problems 09/03/92 All holders of OLs or CPs
Caused by Modifications for nuclear power reactors.
That Were Not Adequately
Reviewed and Tested
92-64 Nozzl e Ring Settings 08/28/92 All holders of OLs or CPs
on Low Pressure Water- for nuclear power reactors.
Relief Valves
92-63 Cracked Insulators in 08/26/92 All holders of OLs or CPs
ASL Dry Type Transformers for nuclear power reactors.
Manufactured by Westing- house Electric Corporation
92-62 Emergency Response 08/24/92 All U.S. Nuclear Regulatory
Information Require- Commission licensees.
ments for Radioactive
Material Shipments
92-61 Loss of High Head 08/20/92 All holders of OLs or CPs
Safety Injection for nuclear power reactors.
92-60 Valve Stem Failure 08/20/92 All holders of OLs or CPs
Caused by Embrittlement for pressurized water
reactors (PWRs).
OL = Operating License
CP = Construction Permit