rt refinery lessons learned

1A REFINERYA REFINERY

UPGRADE PROJECT UPGRADE PROJECT

LESSONS LEARNEDLESSONS LEARNEDAugust 20, 2006August 20, 2006

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PurposePurpose

To share with you lessons learned

during the execution of major

Upgrade Project in A Refinery

Good morning

The purpose of this presentation is to share with you lessons learned during the execution of major Upgrade Project in A Refinery.

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OutlineOutline

z Refinery Upgrade Project Overview

z Major Quality Deficiencies

z Lessons Learned

z Conclusions

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PROJECT OVERVIEWPROJECT OVERVIEW

z Four Conversion Processes

z Six Support Processes

z Eight Utility Support Facilities

z Six Offsite Facilities

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Refinery Plot PlanRefinery Plot PlanNorth Area South Area

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172

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174161

162

163

164150

151

152

153

154

155

140 141142143

144

1017

1018

147

146

386

384

145

262

261

1050

242

272

253

263

264

265

266

244

245

246

273

274

275

276

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199

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181

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183

286

Sub 54

Sub13/24

Sub 52

Sub 16

Sub 17

Sub 12

Sub 22

Sub 65

Sub 93

Sub 92

Sub 8/9

Sub 25

Sub 5

Sub 6Sub

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Sub 23

Sub 1/2

Sub 3/26

Sub 36

Sub 49

Sub 50

Sub 69

Sub 32

Sub 42

Sub 58Sub 43/51

Sub 30

Sub 57

Sub 44

Sub 104

Sub 67

Sub 20

Sub 71

Sub 97

Sub 91

Sub 10

Sub 79

PLT 28

Plant 52 B & T Control

Room

PLT 30

Utilities

Tankage

PLT 490

PLT 52

PLT 20

PLT 71

PLT 10

PLT 9

PLT 16

PLT 26

PLT 25

PLT 40

PLT 27

PLT 45 PLT 415

PLT 32

PLT 44

LPG SALES

PLT 399

PLT 13

PLT 404

PLT 410 &410

A

PLT 2

PLT 139

PLT 493

PLT 488

AC PLT 3

LAB.

Fire Station

Comm. Bldg.

N.A. Traini

ngCent

er

PLT 53

PLT 29

PLT 19 & 19A

CGTG-10

CGTG-11

PS

Utilities

Tankage

Crude Charge Pump Station

PLT 15

PLT 44

CBPH Control Room

CONTROL BLDG

H 2/ PSA

HCK DGA/SWS

VISBREAKER

SULFUR

FLARE AREA

SUB 215A/C

N2

BOILERS

HLPHA/C

LAB

MAT'L YARD

DESALOPS BLDG

F.G.

BLEND

Sub 80

IWWTPNHT/CCR

This slide shows the Refinery Plot Plan. Orange blocks show the location of new conversion processes and green blocks represent support facilities.

The quality deficiencies found were related specifically to plants in the south area (Hydrocracker, Visbreaker, Hydrogen and associated support processes as well as offsite facilities).

This concludes the brief overview of the refinery upgrade project. Now I will move to the summary of major quality deficiencies.

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Major Quality DeficienciesMajor Quality Deficiencies

Welds

Valves

Vessels

Bolts

Rotating equipment

Furnaces

Piping & assoc. components

Exchangers

Elect. & Inst.

Coating

Procedures

Deliverables

Vendor Support

Overlapping

This slide shows major quality deficiencies found in the refinery upgrade project.

Next, I show some of detail deficiencies of these items.

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Welds DeficienciesWelds Deficiencies

z Improper Socket weld joint assembly z Lack of Heat Treatmentz Undersized weldsz Incorrect metallurgy (Rogue welds)z Weld defects: i.e. Porosity, Undercut, Lack of Fusion

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Valves Valves deficienciesdeficienciesz Incorrect specificationz Improper selection and castingz Improper installationz Improper assembly of internalsz Undersized level and flow control valvesz Undersized valve actuatorsz Oversized check valvesz Discrepancy of Relief valve 3% pressure drop requirement

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Fig.1 Check Valve Incorrect Internal Fig.1 Check Valve Incorrect Internal MaterialMaterial

Incorrect Carbon Steel Lock-Ring

Stainless Steel Flapper Pin

IMPACT Release of

auto-ignition material

Release of high H2S to atmosphere

high risk to personal

Description: This shows the quench line check valve stainless steel flapper rod that had an incorrect carbon steel lock ring. The corrosion of the carbon steel lock ring caused the flapper inside the check valve to seize in the open position.

Consequence: The hydrogen quench line check valve is an integral safety component of the Reactor circuit. The seizing of the flapper in the open position was exceptionally dangerous as it allowed high temperature liquid hydrocarbon to back into a low temperature gas piping system.

Magnitude: Six out of 9 hydrogen quench check valves were found with carbon steel lock rings that corroded and caused jamming of the flappers in the open position.

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Fig.2 Incorrect NACE Valve Fig.2 Incorrect NACE Valve

410 Stainless

Steel Trim Material is incorrecteven with

NACE certification

due to excessive

hardness of CHERO valves

ALL REFINING PLANTS

Description: The photo shows the valve wheel nameplate of a CHERO valve that has the incorrect trim for sour service. Even though CHERO certified that the valve meets NACE hardness requirements for sour service, validation testing by CSD proved that the internals were too hard for intended service.

Consequence: Upon entry into sour service the valve stem, seats and disc will crack thus rendering the valve ineffective for isolation requirements.

Resolution: CSD issued Technical Alert # 005/01 on the validity problem of the CHERO valve NACE certification for sour service. The affected CHERO valves were removed from the corporate materials stock system.

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Fig.3 Incorrect Specification

13% Chrome Stainless

Steel Trim Material is incorrectfor sour

service if not stamped

with NACE

certification

Description: This is a valve wheel nameplate identifying an OMB valve with 13% Chrome internals that is not NACE certified and that was installed in sour service.

Consequence: Upon entry into sour service the valve stem, seats and disc will crack thus rendering the valve ineffective for isolation requirements.

Magnitude: A total of 539 valves were found with incorrect valve trim.

Resolution: All valves identified with incorrect trim were replaced.

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Vessels deficienciesVessels deficiencies

z Inadequate designz Improper internal components installationz Failure of internal claddingz Improper coalescer pads material

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Bolts deficienciesBolts deficiencies

z Incorrect Reactors Internal Boltingz Unapproved welded boltz Incorrect Flange bolting

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Fig.1 Reactors internal BoltsFig.1 Reactors internal Bolts

IMPACT Failure of internal

structures Rapid Catalyst beds

movement Loss of required

quench flow pattern Rapid Temp. excursion Catastrophic

hydrocarbon release

Description: This shows the contrast between the correct stainless steel bolting material versus the service damaged and corroded carbon steel bolting.

Consequence: Such severe deterioration of bolting can result in loss of process control of a reactor including temperature excursions due to the shifting/movement of the catalyst beds and the loss of quench hydrogen flow patterns.

Resolution: All 3 Reactors had to be dumped of catalyst to identify and replace the incorrect bolting.

Magnitude: A total of 618 stainless steel bolts required replacement (139 in C-100, 143 in C-101 and 336 in C-200) due to incorrect metallurgy or dimensions.

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Rotating Equipment Rotating Equipment deficienciesdeficiencies

z Undersized motorsz Undersized pulsation dampenerz Substandard trip linkage components for steam turbines z High thrust bearing movementz High vibration of air blowers

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Furnaces Furnaces deficienciesdeficiencies

z Tube Weld Joints Failurez External Casting Defectz Improper tubes thermal extension guidesz Arrived on site completely unassembled

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Fig.1 Furnace Tube Casting Defect

Radiant Section Tubes - Note marked Casting Defect in

catalyst tube

Description: This shows the Steam Reformer Furnace radiant tube arrangement with one catalyst tube marked as having a severe external casting defect.

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Piping & Associated ComponentsPiping & Associated Componentsz Improper Gasket class which caused major incidentz Failed Spiral Gasket z Damaged Ring Jointz Damaged Flange Facez Low corrosion resistance pipingz Passing Vents & Drainsz Excessive piping vibrationz Missing Ring Joint Gasketz Missing Spiral Gasketz Unsymmetrical and unbalanced pipingz Wrong pipe schedules

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Fig.1 Failed Spiral Gasket

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Fig.2 Failed Spiral Gasket (cont.)

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Fig.3 Damaged Ring Joint

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Fig.4 Damaged Flange Face

Major Multi Surface Damage

It was discovered during the inspection of all ring joint gaskets after the fire on October 20, 1998.

Description: This is a top view of damaged 1.5 ring joint thermowellflange on one of the 2nd stage furnace inlet pass.

Resolution: Required repairs were carried out and completed.

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Exchangers deficienciesExchangers deficiencies

z Failure of tube sheet overlay claddingz Failure of Sulfur Considers tube weldsz Leaking header plugsz Deformation of Fin-fan tubesz Excessive gaps between cellsz Undersized lube oil coolers

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Fig.1 Deformation of FinFig.1 Deformation of Fin--fan tubesfan tubes

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Fig.2 High Pressure REAC E-120s

The leaking header box plugs were discovered during the pressuretest of the system with Nitrogen in late 1998 and early 1999.

Description: This shows east side of J80-E-120s Reactor Effluent Air Cooler header box during the repair of leaking header box plugs.

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Fig.3 High Pressure REAC E-120s

Damaged threads/galled gasket surface

It was discovered during the repair of leaking header box plugs.

Required repairs was completed in 1999.

Description: This shows the damaged threads and galled gasket surface on E-120s Reactor Effluent Air Cooler header box.

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Fig.4 Incoloy 825 Plug

It was discovered during the repair of leaking header box plugs in 1999.

Description: This shows the galled threads on plug of E-120s Reactor Effluent Air Cooler.

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Fig.5 Sea Water Exchangers Monel Overlay

Failed Overlay Areas

This shows general failure of monel overlay all over the tube sheet of the Sea Water Exchangers in the South Plants.

The failure was discovered during the repair of leaking exchanger in the Hydrocracker Plant.

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Fig.6 Sea Water Exchangers Monel Overlay

Failed Overlay

Area

This shows a close view of failed monel overlay in one of the Sea Water Exchanger.

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Electrical & Instrument deficienciesElectrical & Instrument deficiencies

z Missing plugsz Improper groundingz Incorrect cable glandsz Incorrect instrument wire installationz Brittle Reactors thermocouplesz Improper thermowell lengthz Inadequate Instrumentation steam tracing designz Inadequate Instrument steam purge designz Improper Electrical Heat Tracing design for Sulfur line

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Fig.1 Electrical & Instrumentation

Improper Cable Gland Use

IMPACT Compromises

area electrical Classification

No proper seal Source of

ignition Reduces

reliability of internal connections

Proper Cable Gland Installation

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Fig.2 Electrical & Instrumentation

Grounding Wire used as 24 Volt Power Supply

IMPACT No grounding

protection Noisy singles

causing trips

Proper Wire Usage

Proper 24 Volt Power Supply

Description: This shows the incorrect 3-wire in 360 installation rather than the required 4 wire configuration for field instrument indicators on pressure, temperature and flow.

IMPACT: The incorrect 3 wire installation does not have grounding protection and it causes intermittent inaccurate readings which can result in major equipment trips.

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Coating deficienciesCoating deficiencies

z Sever external corrosion of: Vessels

Instrumentation stainless steel tubes

Stationary equipment

Spring hangers

Steel structure

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Procedures deficienciesProcedures deficiencies

z Hard to understandz Limited to specific systemz Lacking migration plansz Lacking system flushz Lacking commissioning plans

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Deliverables deficienciesDeliverables deficienciesz Late & incomplete Equipment Manualsz Late Inspection Recordsz Late & incomplete Operating Proceduresz Late as built 3D-CADD and Drawingsz Lacking ISO drawingsz Inadequate Start-up Spare Parts

To overcome these issues we were forced to:Develop in house operation proceduresDevelop facilities interface proceduresOrder start-up spare parts for critical equipmentDevelop ISO drawings

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Vendor Support deficienciesVendor Support deficienciesz Low technical skill representativez Lack of prompt responsez Too defensivez Not existed after the project construction

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Overlapping deficienciesOverlapping deficiencies

z No clear role & responsibilities for all partiesz Lack of continuity of Project Engineerz Lack of accountability

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Lessons Learned 1Lessons Learned 1

PROBLEMSInadequate quality control

EXAMPLEQuality Control delegated to contractors

SOLUTIONDeveloped Quality Program

RECOMMENDATION

Modify contractModify EP

First. Inadequate quality control in the Lump Sum Turn Key contracts.

To ensure effective quality assurance and quality control in the future LSTK contractors, a new contract schedule Q has been added. Additionally engineering practice for contractor QA/QC Requirements has been revised for the same purpose.

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PROBLEMSIncorrect Project Specification LL2-Incorrect Specification

EXAMPLE Seal Welded failure

SOLUTIONSurveyed facilitiesReplaced 88 valves

RECOMMENDATION

Include NACE requirement in all future projects specifications

To avoid such failure in future projects, a formal request to Central Engineering has been made to enforce the NACE requirements for sour service.

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PROBLEMSImproper Piping Design

EXAMPLEUnbalanced piping layout LL3-Unbalanced & Symmetrical Layout

SOLUTIONReplaced 350 feet carbon steel piping

Upgraded construction material to Incoloy 825

Used symmetrical and balanced layout

RECOMMENDATION

Use symmetrical/balanced layout in high corrosive services

Third, improper piping design in the plant Reactors Effluent Air Cooler outlet piping.

The symmetrical and balanced design practice needs to be used for highly corrosive services.

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SOLUTIONRepaired 9 out 11 heater tube weld joints

Replaced one catalyst tube in Steam Reformer

Replaced 5703 valves

RECOMMENDATION

Mandate QA/QC for Vendor supplied equipment in LSTK Contracts

PROBLEMSInadequate Vendor InspectionHeaters arrived completely unassembled

EXAMPLEHeater Tubes FailureLL4-Cracked Furnace tube weld joints

NEWCO Valves Failure

Fourth, an inadequate Vendor Inspection was found in furnace tubes and Newco valves supplied equipments. For heater, PMT did not dedicate the personal to exercise enough vigilance during detail engineering, fabrications, shipment, material control at site and installation.

To ensure high quality Vendor supplied equipment in LSTK contracts, mandate QA/QC requirements for all vendor supplied equipments during supplier selection, review of purchase orders and verification of purchased materials.

Detailed instructions in the contract to include a restricted Vendors list with provisions for the contractor to obtain a no objection letter, Detailed engineering requirements for the LSTK contractor to submit an execution Plan prior to the award.

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PROBLEMSLack of material and construction quality controls LL5-Reactors internal

EXAMPLE Incorrect metallurgy

Rogue weldsValve trim materials, piping components and piping materials.

Defected Socket WeldsSOLUTION

Developed PMI ControlReplaced 618 boltsReplaced 63 flange boltsReplaced 1351 Socket assemblies

Heat treated over 50 welds

RECOMMENDATION

Use an independent third party contractorConduct construction quality field audit by proponent Inspector

Fifth, lack of construction quality controls. Several problems were found during rectification that highlighted improper construction quality such as using carbon steel welding rod in alloy piping.

To ensure effective quality control, we:developed PMI control programreplaced 618 bolts in Hydrocracker reactorsreplaced 63 high temperature flanges boltsreplaced 1351 socket weld assemblies; and heat treated over 50 welds.

To overcome such problem in the future, during construction conduct filed and desk quality audits in frequent basis by the proponent inspector.

A second rectification program was performed to establish the facilitiesmechanical integrity resulting in a safe working environment for our workforce.

25856 Socket Welds in critical services were checked for defects.1350 Butt Welds were tested for rogue materials and crack development.

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PROBLEMSIncomplete and late deliverables

EXAMPLEOperating Procedures

SOLUTIONRewrote all operating procedures into a command format

Developed migration plans & procedures

RECOMMENDATION

Modify contract to link payment schedule to deliverables

Sixth, late and incomplete deliverables had added more workload. Facilities operating procedures were not specific and clear.

All operating procedures were rewritten and converted into a command format to be simple, specific and detailed to include migration and commissioning plans for the new facilities along the existing operational plants.

Contract Schedule C should be modified to link payment schedule to on time project deliverables.

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PROBLEMSLack of continuity of key personnel assigned to the project

EXAMPLE Re-assignment & early release of PMT and contractor key personnel to other jobs

SOLUTION???????????

RECOMMENDATION

Keep essential membersEnforce project teamwork practices

Seventh, lack of continuity of essential personnel assigned to the project had impacted the project quality control negatively. Several PMT and Contractor personnel were reassigned to other projects prior to MCC approval and start-up.

To overcome the problem we worked long hours to compensate for lost project history. In order to eliminate disruption and delays in execution of projects caused by frequent personnel (PMT/Contractor) changes, keep essential members and enforce project teamwork practices throughout all project phases.

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Lessons LearnedLessons Learned

z Quality System

z Contract development

z Design details

z Construction

Based on our actual findings a number of valuable lessons have been learned related to:

Quality SystemContract developmentDesign detailsConstruction

Each lesson will be discussed in details in the following slides.

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Lessons Learned (cont.)Lessons Learned (cont.)

z Quality System Quality control

Quality assurance

Quality auditing

Starting with quality system. The importance of quality system addressing quality control, quality assurance and quality field auditing should be recognized, clearly defined and enforced through all project phases.

The current practice is focusing on desk review and records while there is minimum field quality auditing.

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z Contract development Contract language

Vendors selection

The second lesson is addressing contract development. The contract language must be strong and specific regarding quality control and accountability throughout the whole project. Additions to the company approved vendors list should go through a rigorous qualification process that involves the concerned proponent. A new contract schedule Q was added to address quality system for new projects.

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z Design details Material selection

Project specification

The third lesson is related to design details. Strict controls/checks must be implemented to ensure design, material specification, selection, procurement and installation fully conforms to the Design and Inspection requirements adhering to the Company Standards, design practices and approved vendors list. This should be enforced during the design details phase.

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z Construction Field inspection

Team continuity

Finally is the lesson from construction. Evidently, most challenges have been encountered in the Construction phase. To overcome this, a field quality system must be rigorously enforced. To achieve it, proponents inspection should be actively involved. Quality auditing by project quality management should be extended beyond desk reviews. Specifically it should include random and periodic field inspections and testing of material and craft personal. The continuity of the assigned project team should be maintained throughout all project phases to minimize disruption and delays in execution.

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SummarySummary

z These lessons were very expensive resulting in lost revenues and human casualties.

One incident caused 10 injuries and $2 MM damage.

$40 MM spent for rectification program.

$360 MM lost due to the delay of the start up.

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Summary (cont.)Summary (cont.)

z Low-bed LSTK contract labor force and lack of adequate contractual constraints and project specifications were the major causes for the deficiencies.

z Lack of proper quality control system was evident in every phase of the upgrade project, specifically in the construction phase.

z All the problems occurs with one contractor while other projectswere without major deficiencies.

z Not enough manpower to monitor detail engineering and QA/QC contributed to the problems.

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RecommendationsRecommendations

z Rigorous QA/QC should be recognized, clearly defined and enforced through all project phases.

z Detailed instructions in the contract to include a restricted Vendors list with provisions for the contractor to obtain a no objection letter.

z Quality auditing by project quality management should be extended beyond desk reviews. Specifically, it should include random andperiodic field inspections and testing of material and craft personal

z Involvement of proponent inspection at early stage of project construction will improve the QA/QC.

z Utilizing the experience of existing special system will eliminate the troubles if the same system going to be built.

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FinallyFinally

z The complexity of the refinery upgrade project and all the challenges encountered during and after the execution of the project has left refinery with a valuable experience.

z Involvement of fresh graduate engineers has increased their experience exponentially.

z It is good to share any project lessons learn with others to avoid reoccurrence.

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FiguresFigures

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LL2LL2--Incorrect SpecificationIncorrect Specification

Cracked Bonnet Seal Weld

IMPACT Release of




Seal Welded Bonnet Y Globe Valve

This photo shows the Y Globe seal welded bonnet valve that cracked after the completion of catalyst sulfiding. The failure was caused by sulfide stress corrosion cracking as the valve was not certified (NACE) for sour service per original design specification.

A thorough facilities surveyed was conducted and a total of 88 valves were identified and replaced.

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LL3LL3--Unbalanced & Symmetrical Unbalanced & Symmetrical LayoutLayout

This slide shows the original symmetrical and unbalanced layout of the Reactors Effluent Air Coolers outlet piping.

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LL3LL3--Poor Piping DesignPoor Piping Design

Reactor Effluent Air Cooler Outlet

unbalanced and symmetrical Carbon

Steel Piping with end-cap

IMPACT Release of



high risk to personal Observed excessive

internal corrosion in end-cap

This photo shows the original poorly designed carbon steel Reactors Effluent Air Cooler (REAC) piping that experienced accelerated internal corrosion.

The photo on the right shows the end cap cut-out from the carbon steel common outlet header with a high internal corrosion

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LL3LL3--Symmetrical & Balanced LayoutSymmetrical & Balanced Layout

This slide shows the proper layout of piping for high corrosive services in which end cap was eliminated.

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LL4LL4--Cracked Furnace tube weld Cracked Furnace tube weld jointsjoints

IMPACT Major tube

rupture High H2S & high

Temperature material release to atmosphere

High risk exposure to personal

Cracked Tube Weld Joints

This shows side view of failed furnace tube weld joints in the plant furnace due to improper weld heat treatment during construction.

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LL4LL4--Sever External Casting DefectSever External Casting Defect

Closer View of Casting Defect

Remaining thickness

IMPACT Major

explosion Substantial

damage Serious risk to

personal Loss of

confidence in equipment

This shows a closer view of the radiant section catalyst tube with the severe external casting defect and the radiography profile of the casting defect of the catalyst tube.

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LL4LL4--Casting DefectsCasting Defects

Unacceptable Internal Repairs

IMPACT Release of




Casting Defect Areas

The left photo shows valve body casting defect while the right photo show unacceptable repair of valve using incorrect electrode.

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LL5LL5--Reactors internalReactors internal

IMPACT Failure of internal

structures Rapid Catalyst

bed movement Loss of required

quench flow pattern

Rapid Temp. excursion

Catastrophic hydrocarbon release

Corroded Carbon Steel Bolt with cracked nut

The left photo shows internal structure with failed bolts while the right photo shows a close up view of a corroded carbon steel nut and bolt.

A total of 618 stainless steel bolts required replacement (139 in C-100, 143 in C-101 and 336 in C-200) due to incorrect metallurgy or dimensions.

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LL5LL5--Reactors internal (cont.)Reactors internal (cont.)

IMPACT Major failure of catalyst bed

support beams Rapid catalyst bed

movement Loss of quench flow pattern Uncontrollable temperature

excursions Potential catastrophic

release of high pressure, H2S, Auto-ignition materials

Stainless Steel Bolts versus Damaged Carbon Steel Bolts

This shows the contrast between the correct stainless steel bolting material versus the service damaged and corroded carbon steel bolting.

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LL5LL5--Use of Unapproved Welded BoltsUse of Unapproved Welded Bolts

Two Unapproved Welded Bolts

IMPACT Release of




Unapproved Welded Bolt

This shows failed of non approved welded two bolts found on the plant feed pump discharge line.

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LL5LL5--Incorrect Flange BoltingIncorrect Flange Bolting

B7

B16

IMPACT B7 can lose its

strength causing the flange to open releasing auto-ignition material

High risk to personal

Installation of Inferior B7 Bolts Instead of High Temperature B16 Bolts

B7B16

This shows a high temperature flange with incorrect B7 bolts installed instead of the required B16 bolts.

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LL5LL5--Improper Socket weld joint Improper Socket weld joint assemblyassembly

Only fillet weld

attachment secures the

entire nipple

No Insertion

IMPACT Release of


High risk exposure to personal

This socket weld radiograph shows the lack of insertion of the nipple into the socket joint. The nipple is only secured by the fillet weld.

A total of 1346 socket weld joints were found with unacceptable excessive gaps during the course of radiographic surveys for weld quality on all of the South Plants.

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LL5LL5--Improper Socket weld joint assembly Improper Socket weld joint assembly (cont.)(cont.)

IMPACT Weaker fillet

weld joint Lack of

insertion strength

High risk and hidden potential failure

Inserted cut nipple pup piece to fill insertion gap

This radiograph shows the use of an illegal insert to make-up for being dimensionally short. Such an illegal insert provides no insertion strength.

A total of 5 piping locations where found.

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LL5LL5--SOCKET WELD FAILURESOCKET WELD FAILURE

This is the Materials Lab cross section of the socket weld that failed on December 14th 1999. The fracture crack started from the inside of the weld and propagated outward to failure. The cause of the failure was high cycle fatigue and a contributing factor was theinternal root defect - note the lack of fusion on the horizontal plane. Lack of fusion can be the initiation site for fatigue cracking in vibration service and can drastically reduce the service life of a socket weld. The result of this fatigue failure was the total detachment of the weld from the socket, with the resultant de-pressuring of 2700 PSIG 99% pure hydrogen into the area.

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LL5LL5--SOCKET WELD RADIOGRAPHSOCKET WELD RADIOGRAPH

Radiography is the only method that can be used to find internal root defects in a socket weld. Because of the failure, radiography was carried out on associated socket welds in the plant.

We are looking at a socket weld (nipple and socket fitting) The triangular feature is the weld and dark space is indicative of lack of penetration and lack of fusion. You can also see a linear indication propagating from the inside outward.

This a weld that had not failed but if you can see the same type of linear crack-like indication initiating from the internal weld defect and propagating to the surface as in the weld that had failed. This radiograph is analogous to a picture of a crack in the progress of propagating to the surface.

These indications are what has caused us to shutdown the plants as they cannot be detected by normal on-line NDT techniques. So far we have found 560 locations where these defects exist. It should also be understood that these defects have a deleterious impact on the life of these welds of a factor of 8 versus welds of proper quality.

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LL5-Poor Construction of Socket Weld

This fillet weld gauge shows the required weld size.

Note the amount of weld metal missing.

It was discovered during the survey of the welding problem in critical service alloy piping systems.

Description: This shows socket weld that is undersize.

Resolution: Require weld size was provided as per ANSI B31.3 requirements.

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Cracking Area after

completion of Catalyst Sulfiding

IMPACT Release of




LL5LL5--Insufficient heat treatment of Insufficient heat treatment of weldswelds

This shows failed weld due to improper heat treatment to meet sour service design specification.

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LL5LL5--Socket weld & PMI Quality Control Flow Socket weld & PMI Quality Control Flow ChartChart

Socket Weld

Control Sheets

Radio Graph

Scaffolding / Insulation

NDT

Welding Coordinator

Re-Work

Bracing NDT (DPT)

Data Process

Planning Coordinator

Completed

Planning Unit

If Vibration

Area Bracing NDT (DPT)

If AcceptedNot

Yes

PMI Coord.

Control Sheets

Scaffolding / Insulation

Planning Coordinator

PMI

Repairs

NDT

Rework

IfScaffold/ Insulation

Pressure Test

Planning Unit

Work

Not

IfAccepted

Pressure Test

Planning Unit

Planning Unit

Reports

Yes

If Vibration

Area

Yes

Not

If Vibration

Area

Yes

Not

If Vibration

Area

Yes

NotIf

Vibration Area

Not

Yes

Welding Coordinator

Yes

Not

Yes

Not

IfAccepted

Yes

Not

Planning Unit

New materials received

PMI & color coding

Due to these defects two rectification programs were conducted using proper quality control.

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LL5LL5--MATERIAL COLOR CODINGMATERIAL COLOR CODING

z Material Description Assigned Colorz Carbon Steel valves for:

non corrosive (Trim 8) White sour service (Trim 12) Red cold service (Trim 12) Black & White caustic service (Trim 12) Orange

z 1 Chrome Moly Bluez 5 Chrome Moly Yellowz 9 Chrome 1 Moly Greenz 300 Series Stainless Steel Black/type No.

To ensure effective quality control during the remediation color coding construction material was utilized.

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LL5LL5--PMI INSTRUMENTPMI INSTRUMENT(Texas Nuclear Alloy Analyzer)(Texas Nuclear Alloy Analyzer)

To correct the deficiency a PMI program was used to identify improper material utilization.

This PMI instrument was used to identify construction materials.

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LL5LL5--THRESHOLD LIMIT OF PMI THRESHOLD LIMIT OF PMI MACHINEMACHINE

PMI Machine

PMI Sensing Probe

t = 0.350

Butt-Weld

Pipe

The PMI machine uses a nuclear source to detect concentration levels of various metals in a weld or piping. From the data gathered we can determine whether the proper metallurgy is in place. Thismachine has a detection limitation up to a depth of 0.350 as we proved during the first remediation effort. That means it can detect alloy dilution if it is within 0.350 of the surface.

If the piping thickness is greater than this limit, then we need to alternative techniques to inspect for rogue welds. I will show you one of them in the coming slides.

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76

LL5LL5--BURIED ROGUE WELDSBURIED ROGUE WELDS

Base Metal

Incorrect Electrode -Rogue Weld Passes

Before I go further, let me define for you what we mean by the term ROGUE WELD.

As shown in this slide, the definition of a rogue weld begins with the usage of an incorrect electrode, that is an electrode whose metallurgy does not match the base piping or component alloy composition and which is used at the beginning of the welding process in the root and / or in the hot passes. As we noted earlier, surface PMI cannot find these rogue passes if they are deeper than 0.350 due to instrument limitations. In that case we can utilize flat grinding to allow the instrument to assess the weld composition

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LL5LL5--FLAT GRINDINGFLAT GRINDING

TN MachineComputer TN Sensing Probe

t = 0.350

t 0.718

Butt-Weld

Carbon Steel Pipe

This can damage defect and non defect welds which required further repair.

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LL5LL5--Secound Rectification activitiesSecound Rectification activities

2486331990 MATERIAL 26243 1380

SOCKET WELDS

PMI READINGS

12502000CONTROL SHEETS

1021612000ISOMETRICS

COMPLETE as of 3/20/01ESTIMATEACTIVITY

COMPLETE as of 4/7/01

Increment

203511306

7851090

30678300000 48566 17888327425856 5774 2500

This slides shows the current status of all of the activities as of March 20th 2001 and as of April 7th, 2001 respectively. As noted earlier, isometric drawings are about 94% complete, control sheets are over 100% complete, PMI work is around 16% complete, socket welds are about 22 % complete, and material ordering approximately 82 % complete.

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