MAKE SURE LOCK OUT 2 - NDT.net

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MAKE SURE LOCK OUT

BEFORE START THE WORK

Badak LNG Overview

Problem Description and Assessment Approach

Examination Result

Assessment Result

Conclusions

1

2

3

4

5

3

4

C

F

G

Gas Pipelines

Oil Pipelines

10%

15%

20%

55%Shareholders

INDONESIA

1, 2, 3…: LNG storage tank

AB

C

D

E

F

G

H

G/H

C/D

A/B

Cold Water Intake

Dock 2

Dock 1

Dock 3LPG

Plant

12

34

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1, 2, 3…: LNG storage tank

Cooling Water Intake

DOCK 2

DOCK 1

DOCK 3

LPGPlant

A

BC

D

E

F

G

H

LNG train

LNG storage tank

6

5

No. Trains : 8 (22.5 MTPA LNG & 1.1 MTPA LPG)Loading Docks : 3 (1 LNG, 2 LNG/LPG)

Feed Gas Supply : 3.7 BSCFD with 4 Pipelines 2@36”; 2@42”

Boiler Boiler

6

LetdownStation

Steam Condensate Utilities -1

NC

LetdownStation

LetdownStation

LetdownStation

Back Press.Turbine

CompressorDriver

CompressorDriver

Back Press.Turbine

Steam Condensate Utilities -2

CondensingTurbine

CondensingTurbine

PumpDriver

PumpDriver

HP Steam 61-62 kg/cm 2g ;

450 oC

MP Steam17.5 kg/cm 2g ;

316 oC

LP Steam3.5 kg/cm 2g ;

218 oC

Boiler Utilities-1 Boiler Utilities-2

Surface

Condensers

Surface

Condensers

Note: Green : Open, Red : Close

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Design code ANSI B 16.34

Size / ANSI Class 24” / 600

Valve type Gate flexible wedge type disc

Year installed 1989

Material specification

ASTM A217 WC6

ServiceHigh pressure superheated steam

Design pressure 75 kg/cm2g (1066 Psig)

Design temperature

450 ºC (842 ºF)

Operating pressure 61- 62 kg/cm2g (882 psig)

Operating temperature

450 ºC (842 ºF)

Insulation N/A

N

Utilities -2 Utilities-1

Cracked Valve

Crack occurred at two locations: Body

and Bonnet

� Material Test

� Flaws Sizing : Alternating Current Potential Drop (ACPD)

� Thickness Measurement : Ultrasonic Test

� Material Characterization:

Chemical Composition, Tensile Testing, Fracture Toughness (CTOD) Testing and Fatigue Growth Testing

� Finite Element Modelling : Abacus

Software

� Fitness for Service Assessment: APII

579 Section 9 Level 3B

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Red : Crack B, blue: Crack C, green: Crack D and

yellow Crack E

Crack A on valve Body

9Flaw Length A = 170 mm, B = 33 mm, C = 120 MM, D = 70 mm, & E = 23 mm)

10Note:Thickness of Remaining Ligament = Average Thickness – Maximum Crack Height

Material Characterization

Test Type Result and Remark

Chemical CompositionMeet Requirement ASTM A 217 Grade WC6 but siliconcontent exceeded 0.6%

Tensile Testing

� Test at 23 ºC Meet Requirement ASTM A 217 Grade WC6

� Test at 130 ºC YS = 225 MPa, TS = 487 MPa, EL = 16 %, RA = 23 %

Fracture Toughness (CTOD) at 130 ºC

Minimum value is 0.38 mm

Fatigue Growth Testing at 130 ºC

A = 3.1x10-17, m = 4.4 and ∆Ko = 184 Nmm-3/2

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12

Bonnet Cap

Bonnet

West Side

East Side

End Cap

West SideEast Side

Case LocationAverage Von-Mises

stress (MPa)Stress range, ∆σ (MPa)

Low temperatureValve body 103.5 -

Bonnet 89.5 -

High temperatureValve body 175.5 -

Bonnet 163.5 -

Low temperature minus 10 ºCValve body 102.5 -

Bonnet 85 -

Low temperature plus 20 ºCValve body 107 -

Bonnet 94 -

Low temperature – 10 ºC + 20 ºCValve body - 4.5

Bonnet - 9

Low - High temperatureValve body - 72

Bonnet - 74

Valve Temperature Low Temperature Case High Temperature Case

West Side 114.4 ºC 415 ºC

Bonnet 73 ºC 402 ºC

East Side 70.6 ºC 412 ºC

Note:

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Failure Assessment Diagram

14

Str

es

s In

ten

sit

y R

ati

o,

Kr

Load Ratio, Lr

15

Fla

w H

eig

ht,

a (

mm

)

Flaw Length , 2c (mm)

Unsafe

Safe

Crack Critical Value for Bonnet

16

Fla

w H

eig

ht,

a (

mm

)

Flaw Length , 2c (mm)

Unsafe

Safe

Case Remark

Crack on Body

� Low Temperature Case –10 ºC + 20 ºC No crack growth

� Swing between low and high Temperature Case

Crack growth occurred

Crack on Bonnet

� Low Temperature Case –10 ºC + 20 ºC No crack growth

� Swing between low and high Temperature Case

Crack growth occurred

Crack Growth Analysis

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Crack Growth Analysis - Body

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Crack Growth Analysis - Bonnet

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� The 170 mm long flaw located at the valve body had a semi-elliptical shape with a maximum height of 31.8 mm.

� The equivalent flaw size on bonnet was determined to be 16 mmhigh and 130 mm long.

� Valve body flaws are in the safe region of the API 579 Level 3Bfailure assessment diagram.

� Crack growth analysis showed that the crack on valve not likely togrow if the valve experiences limited temperature cycling (between10 ºC below to 20 ºC above the low temperature case) but sub-critical growth of the body crack will occur if the valve experiencestemperature cycling between the low and the high temperaturecase

� Close monitoring of temperature has been conducted to preventany temperature swing beyond lower temperature case.

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Thank you

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