ASME VIII Div 2 Vessels-End of Life

My ASME VIII Div 2 VesselsMy ASME VIII Div 2 Vessels Are at Are at the End of Their Life !the End of Their Life !

What NowWhat Now??

IPEIA IPEIA ConferenceConference, BANFF February 2007, BANFF February 2007Izak J Roux P. Eng.Izak J Roux P. Eng.

RAE Engineering & Inspection LtdRAE Engineering & Inspection [email protected]@raeengineering.ca

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What did the Div 1 vessel said to What did the Div 1 vessel said to the Div 2 vessel after the 10 year the Div 2 vessel after the 10 year

inspection?inspection?

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This is the first day of the rest This is the first day of the rest of your life!of your life!

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Div 2 Vessels Div 2 Vessels -- OverviewOverview

1.1. IntroductionIntroduction2.2. Div 2 vs. Div 1 Div 2 vs. Div 1 ––PhilosophyPhilosophy3.3. ABSA RequirementsABSA Requirements4.4. Case Study 1 Case Study 1 –– SeparatorsSeparators5.5. Case Study 2 Case Study 2 –– Accumulators HP & LPAccumulators HP & LP6.6. Owners StrategyOwners Strategy7.7. ConclusionConclusion

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IntroductionIntroduction

Div 2 vessels Div 2 vessels –– we forgot about themwe forgot about themLuckily Luckily –– ABSA rememberedABSA rememberedWhat now?What now?Let us Analyze!Let us Analyze!

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ASME 8 Div 1 vs. Div 2ASME 8 Div 1 vs. Div 2

ASME 8 Div 1ASME 8 Div 1Design by committeeDesign by committeeDiv 1 came out of 1900’s public pressure, get it Div 1 came out of 1900’s public pressure, get it safe safe –– Margin of safety.Margin of safety.Low allowable stressLow allowable stressHigh Safety factorHigh Safety factorPenalties Penalties –– welding, inspectionwelding, inspectionConservativeConservative

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ASME 8 Div 2ASME 8 Div 2Design for higher pressure and fatigueDesign for higher pressure and fatigueDiv 2 later technology.Div 2 later technology.Higher allowable stressHigher allowable stressFor fixed locationFor fixed locationIncreased inspectionIncreased inspectionLess ConservativeLess Conservative

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ASME 8 Div 2ASME 8 Div 2Stress Analysis Stress Analysis ––

Primary stress Primary stress Secondary stressSecondary stress

Lower Design Factor/Margin of SafetyLower Design Factor/Margin of SafetyPressure >3000 psi (20.6 MPa) (for >600psi)Pressure >3000 psi (20.6 MPa) (for >600psi)Fatigue Analysis > 1000 CYCLESFatigue Analysis > 1000 CYCLESDesign SpecificationDesign Specification

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REMEMBERREMEMBERLife is based on anticipated load cyclesLife is based on anticipated load cyclesOperation and maintenance log is requiredOperation and maintenance log is requiredFatigue evaluation may be required after Fatigue evaluation may be required after useful life by the useruseful life by the userUser Specification VS Operational User Specification VS Operational SpecificationSpecification!!!!

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Section VIII Division Section VIII Division 11

Section VIII Division Section VIII Division 22

Pressure LimitsPressure Limits Normally up to 3000 psigNormally up to 3000 psig No limits either way, usually 600+ psigNo limits either way, usually 600+ psig

ExperimentalExperimentalStress AnalysisStress Analysis

Normally not requiredNormally not required May be requiredMay be required

UserUser User or designated agent to provideUser or designated agent to providespecifications (see Uspecifications (see U--2(a))2(a))

User's Design Specification with detailed User's Design Specification with detailed design requirements (AGdesign requirements (AG--301.1) include301.1) includeAD 160 for fatigue evaluationAD 160 for fatigue evaluation

ManufacturerManufacturer Manufacturer to declare compliance inManufacturer to declare compliance indata reportdata report

Manufacturer's Design Report certifyingManufacturer's Design Report certifyingdesign specification and code compliancedesign specification and code compliancein addition to data reportin addition to data report

Professional Professional EngineerEngineerCertificationCertification

Normally not requiredNormally not required Professional Engineers' Certification of Professional Engineers' Certification of User's Design Specification as well as User's Design Specification as well as Manufacturer's Design ReportManufacturer's Design ReportProfessional Engineer shall be Professional Engineer shall be experienced in pressure vessel design experienced in pressure vessel design

Safety Relief Safety Relief ValveValve

U Stamp with Addition markingsU Stamp with Addition markingsincluding W, P, B, RES; L, UB, DF; RT, HTincluding W, P, B, RES; L, UB, DF; RT, HT

U2 Stamp with Additional markingU2 Stamp with Additional markingincluding HTincluding HT

Hydrostatic Hydrostatic TestTest

Hydrostatic Test 1.3 (Was 1.5 before the Hydrostatic Test 1.3 (Was 1.5 before the use of the 3.5 Design Factor in the 1999 use of the 3.5 Design Factor in the 1999 Addenda)Addenda)

1.251.25

Pressure Cycles in FatiguePressure Cycles in Fatigue

FullFull--range pressure cycles including range pressure cycles including start up and shutdownstart up and shutdownPressure variation exceeds 20% of the Pressure variation exceeds 20% of the MAWPMAWPNumber of HydroNumber of Hydro--teststestsPressure disturbancesPressure disturbances

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ABSA REQUIREMENTSABSA REQUIREMENTS

Registration Registration –– we have done thatwe have done thatDesign Specifications Design Specifications vsvs OperationsOperationsWake Up and tell us what have you done Wake Up and tell us what have you done to these Div 2 vessels!!!to these Div 2 vessels!!!Operational logOperational log-- show me!show me!

Monitor pressure and temperature Monitor pressure and temperature

Future Life ReportFuture Life Report

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ABSA RequirementsABSA Requirements

As per jurisdiction requirements for cyclic As per jurisdiction requirements for cyclic loaded vessels, the pressure and temperature loaded vessels, the pressure and temperature cycles need to be reviewed and compared cycles need to be reviewed and compared with the fatigue cycles that were anticipated with the fatigue cycles that were anticipated at the design stage.at the design stage.Owners Specification Owners Specification Manufactures SpecificationManufactures SpecificationOperating SpecificationOperating Specification

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Case StudiesCase Studies

Approached followed for AnalysisApproached followed for AnalysisCheck User Requirements/specificationCheck User Requirements/specificationCheck inspection recordsCheck inspection recordsCheck actual operations Check actual operations ––

pressure and temperature cyclespressure and temperature cyclesShutdownsShutdownsNumber of hydro tests done to dateNumber of hydro tests done to dateRepairsRepairsPossible change in product Possible change in product –– change in corrosion ratechange in corrosion rate

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Case Study 1 Case Study 1 -- SeparatorSeparator

BackgroundBackgroundHorizontal vessels, 76 mm thicknessHorizontal vessels, 76 mm thicknessThese vessels been in service since 1996These vessels been in service since 1996Cyclic serviceCyclic servicePressure cycle and Temperature CyclePressure cycle and Temperature CycleSweet serviceSweet service

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DiameterDiameter 78 in (1980 mm)78 in (1980 mm)LengthLength 30 ft (9145 mm)30 ft (9145 mm)Wall ThicknessWall Thickness 3.0 in (76 mm) 3.0 in (76 mm) MAWPMAWP 1650 psi (11.38 MPa)1650 psi (11.38 MPa)Operating Temp. 100 F (38 Operating Temp. 100 F (38 °°C)C)

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OPERATIONAL CYCLE (TYPICAL)OPERATIONAL CYCLE (TYPICAL)Data Reference Data Reference Dec 2000 to Apr 2001Dec 2000 to Apr 2001Maximum Pressure 1472 psi (10.1 MPa)Maximum Pressure 1472 psi (10.1 MPa)Minimum Pressure 228 psi (1.6 MPa)Minimum Pressure 228 psi (1.6 MPa)Maximum Temp.Maximum Temp. 100 100 °°F (38 F (38 °°C) C) Minimum Temp. 45 Minimum Temp. 45 °°F (7 F (7 °°C)C)

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Separator Separator –– Pressure dataPressure data

Separator V-2002 Pressure Cycle

0200400600800

1000120014001600

12/4/

2000

12/18

/2000

1/1/200

11/1

5/200

11/2

9/200

12/1

2/200

12/2

6/200

13/1

2/200

13/2

6/200

14/9

/2001

4/23/2

001

Date

Pres

sure

(psi

)

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Separator Separator –– Pressure dataPressure data

Separator V-2001 Pressure Cycle

0200400600800

1000120014001600

12/4/

2000

12/18

/2000

1/1/200

11/1

5/200

11/2

9/200

12/1

2/200

12/2

6/200

13/1

2/200

13/2

6/200

14/9

/2001

4/23/2

001

Date

Pres

sure

(psi

)

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Separator Separator –– Temp dataTemp data

Separator V-2001 Temperature Cycle

0.020.040.060.080.0

100.0120.0

12/4/

2000

12/18

/2000

1/1/200

11/1

5/200

11/2

9/200

12/1

2/200

12/2

6/200

13/1

2/200

13/2

6/200

14/9

/2001

4/23/2

001

Date

Tem

pera

ture

(F)

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Fatigue AnalysisFatigue AnalysisLow cycle Low cycle Number of cycles for Number of cycles for 10 years operation10 years operationFatigue AnalysisFatigue Analysis

1 per year1 per year= 274 cycles= 274 cycles

= Exempted= Exempted

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ConclusionsConclusions

Separators will see >1000 cycles in 40 Separators will see >1000 cycles in 40 yearsyearsBetter recording of temp. & pressure Better recording of temp. & pressure cycles cycles –– review changes annuallyreview changes annuallyDeDe--rate to Div 1 may be consideredrate to Div 1 may be considered

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Case Study 2 Case Study 2 -- AccumulatorsAccumulators

Low and High Pressure Low and High Pressure AccumulatorsAccumulators

Fabricated in 1986 Fabricated in 1986 The vessels are in cyclic service The vessels are in cyclic service Fatigue life of 20 yearsFatigue life of 20 yearsDesign to ASME VIII Division 2. Design to ASME VIII Division 2.

continued

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Low Pressure (left) & High Pressure (right)


LP AccumulatorLP AccumulatorDiaDia –– 72 in72 inHeight Height –– 22’ 7”22’ 7”MAWP MAWP –– 769 psi769 psiTemp Temp –– 69 69 ººCCC.A C.A –– 0.0 in0.0 inWall thickness =1.63 inWall thickness =1.63 inTmin = 1.62 in Tmin = 1.62 in

HP AccumulatorHP AccumulatorDiaDia –– 34 in34 inHeight Height –– 26’26’MAWP MAWP –– 3937 psi3937 psiTemp Temp –– 38 38 ººCCC.A. C.A. –– 0.065 in0.065 inWall thickness = 4.45 inWall thickness = 4.45 inTmin = 4.43 inTmin = 4.43 in

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Criterion Low Pressure Accumulators

Maximum Pressure 737 psi (5.0 MPa)

Minimum Pressure 469 psi (3.2 MPa)

Ambient Temperature 65 0F (18 0C)

No. of effective cycles Refer to Appendix A

Design Life 150000 cycles/year for 20 years

No. of Hydro test 4

Operating Data for Low Pressure Accumulator

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Criterion High Pressure Accumulators

Maximum Pressure 3645 psi (25.1 MPa)

Minimum Pressure 3297 psi (22.7 MPa)

Ambient Temperature 65 0F (18 0C)

No. of effective cycles Refer to Appendix B

Design Life 150000 cycles/year for 20 years

No. of Hydro test 5

Operating Data for High Pressure Accumulator

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OPERATIONSOPERATIONSRecords Records –– complete, linked to production complete, linked to production recordsrecordsHistory of the operating log is available in History of the operating log is available in the plant. Typical operating data history the plant. Typical operating data history was received from the plant.was received from the plant.Press cycle is fixed Press cycle is fixed –– small variation small variation

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LP cyclesLP cycles

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HP CyclesHP Cycles

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Inspection RecordsInspection RecordsDetailed inspections well recordedDetailed inspections well recordedUT Surveys done in 2003 and 2005 UT Surveys done in 2003 and 2005 Used same 200 x 200mm gridUsed same 200 x 200mm gridDetail internal inspection in 2006Detail internal inspection in 2006

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Criterion LP AccumulatorMAWP 769 psi (5.30 MPa)Corrosion Allowance nilMinimum required thickness for

Cylindrical Shell1.62 in (41.2 mm)

Nominal Thickness Cylindrical Shell 1.63 in (41.3 mm)

UT Thickness Cylindrical Shell 1.638 in (41.6 mm)

Minimum required thickness for Elliptical Head

1.58 in (40.22 mm)

Nominal Thickness for Elliptical Head 1.63 in (41.3 mm)

UT Thickness for Elliptical Head 1.64 in (41.66 mm)


Criterion HP Accumulator

MAWP 3937 psi (27.15 MPa)

Corrosion Allowance 0.0625 in (1.6 mm)

Minimum required thickness for Cylindrical Shell

4.43 in (112.7 mm)

Nominal Thickness for Cylindrical Shell 4.50 in (114.3 mm)

UT Thickness for Cylindrical Shell 4.5 in (114.3 mm)

Minimum required thickness for Hemispherical Head

1.95 in (49.68 mm)

Nominal Thickness Hemispherical Head 2.141 in (54.4 mm)

UT Thickness Hemispherical Head 2.291 in (58.2 mm).



UT InspectionUT InspectionHP AccumulatorHP AccumulatorNo ManwayNo Manway

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Finite Element Models used for both Finite Element Models used for both vesselsvessels

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LP FEM ModelLP FEM Model

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HP FEM ModelHP FEM Model

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AnalysisAnalysisLP AccumulatorLP AccumulatorMembrane StressMembrane Stress

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LP Accumulator

Primary & SecondaryStress Intensity

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HP AccumulatorHP AccumulatorPeak Stress IntensityPeak Stress Intensity

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Results Fatigue damageResults Fatigue damage

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Major area of discontinuity LP Vessel

No. of Cycles 4500000

Pressure Difference for cycles 268 psi (1.85 MPa)

Alternating Stress Intensity 11840 psi (81.64 MPa)

Cumulative Damage 0.90

Cumulative Damage for LP Accumulator next 10 years

Condition I


No. of Cycles 200

Correct Cumulative Alternating Stress Intensity 8751.79 psi (60.34 MPa)

Cumulative Damage 2.85E-08

Condition II


No. of Cycles 7008000



Condition III


No. of Cycles 5



Total Cumulative Damage 7.511E-05

Cumulative Damage HP Accumulator for next 20 years


ConclusionsConclusionsAdvantages Advantages Full history of pressure and temperature Full history of pressure and temperature cyclescyclesDetailed inspection reports Detailed inspection reports –– UT surveysUT surveysIdentified inspection areas to monitorIdentified inspection areas to monitor

Manway and nozzlesManway and nozzles

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BenefitsBenefitsExtended life 10 years for LPExtended life 10 years for LPExtended life 20 years for HPExtended life 20 years for HP

SurpriseSurpriseLP has shorter life than HPLP has shorter life than HP

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Owner’s StrategyOwner’s Strategy

Compare User / Fabricator & Operational Compare User / Fabricator & Operational specifications annuallyspecifications annuallyReview Failure Mechanisms Review Failure Mechanisms ––insp. planinsp. planUnderstand the vessels aging Understand the vessels aging ––

is it only fatigueis it only fatiguepressure cycles or temperature cycles.pressure cycles or temperature cycles.

Can I stay below 1000 cycles?Can I stay below 1000 cycles?

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Small change in operations can extend the Small change in operations can extend the life.life.Cumulative damageCumulative damage

startstart--up, up, Hydro testsHydro testspressure cycles pressure cycles –– max, min and avg. max, min and avg.

Record everything Record everything –– keep good recordskeep good records

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RememberRemember

24RAE

“If it is not written down, it does notexist.”

“If it is not written down, it does notexist.”

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Owners StrategyOwners Strategy

Div 2 or Div 1Div 2 or Div 1Do you really need to go there?Do you really need to go there?Is fatigue an issue?Is fatigue an issue?Is high pressure an issue?Is high pressure an issue?It do not have to be a problem It do not have to be a problem –– need a need a integrity strategy for life. integrity strategy for life.

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ConclusionConclusion

A letter from ABSA should not be a A letter from ABSA should not be a surprisesurpriseOwner should manage Div 2 vesselOwner should manage Div 2 vesselEngineering should check operational duty Engineering should check operational duty cycle and compare with design cycle cycle and compare with design cycle –– do do not wait 10 yearsnot wait 10 yearsOperations should monitor and record all Operations should monitor and record all stress cycles stress cycles –– pressure and temperaturepressure and temperature

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Chief inspector bring all info on record and Chief inspector bring all info on record and track usage track usage –– communicate with communicate with operations and engineeringoperations and engineeringAny change in operational conditions Any change in operational conditions should go through MOC and check should go through MOC and check influence on design specification and influence on design specification and updateupdate

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User’s ResponsibilityUser’s Responsibility

User Design’s SpecificationUser Design’s Specification –– To specify To specify whether a fatigue analysis shall be made whether a fatigue analysis shall be made for cyclic servicefor cyclic serviceCertification of User’s Design specificationCertification of User’s Design specification–– A Professional Engineer shall certify to A Professional Engineer shall certify to the compliance of the requirementsthe compliance of the requirements

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Manufacture’s ResponsibilityManufacture’s Responsibility

Compliance with RequirementsCompliance with Requirements –– Manufacturer Manufacturer shall certify with Data Reportshall certify with Data ReportManufacturer’s Design ReportManufacturer’s Design Report ::

Design CalculationDesign CalculationDrawingDrawing

Certification of Manufacturer’s Design Report Certification of Manufacturer’s Design Report –– A A Professional Engineer shall certifyProfessional Engineer shall certify

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Final factors in the life of an Final factors in the life of an ASME 8 Div 2 VesselASME 8 Div 2 Vessel

SafetySafetyReliabilityReliabilityOwnershipOwnership

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THE ENDTHE END

Thank You!Thank You!

ANY QUESTIONS?ANY [email protected]@raeengineering.ca

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ASME VIII Div 2 Vessels-End of Life

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