Tests d'Etancheite Sur Methaniers

DELIVERING TRUST BETWEENDELIVERING TRUST BETWEEN PEOPLE, ORGANISATIONS AND GOVERNMENTSGOVERNMENTS

LNGC LT in the world by SGSLNGC LT in the world by SGS

(Damen) France(Drydocks World Dubai) UAE

(Damen) France

(MMHE) Malaysia

Anywhere

in the world

(SHI, HHI, Hanjin) Korea

(Navantia) Spain in the world

(MHI) Japan

(Navantia) Spain

(N-KOM) Qatar(Sembawang, Keppel) Singapore

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( g, pp ) g p

LT from new shipbuilding to in-service

Our clients from new shipbuilding (more than 97 vessels)

LT from new shipbuilding to in-service

Our clients from new shipbuilding (more than 97 vessels)BG, BP, AP Moller, MOL, NYK, K Line, Teekay, MISC, SK, Shell, MaranGas, Hyundai, Hanjin, OSG, Exmar, ProNav, ILTC, QGTC, Golar LNG, GasLog LNG Services Hoegh LNG BW Gas Chevron etcGasLog LNG Services, Hoegh LNG, BW Gas, Chevron, etc.

More than 300 Membrane type LNG Vessels in service• Every 5 years in drydock (test strongly recommended)

– Every 2.5 years in drydock or during sailing (good to know if available)• Test required if any repair done in cargo tank

Main repair shipyards in the worldMain repair shipyards in the world• Sembawang & Keppel shipyard in Singapore• Navantia shipyard in Spain• Drydocks World – Dubai shipyard in UAE• NKOM shipyard in Qatar• Fujairah, Singapore anchorage or voyage in the world

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Fujairah, Singapore anchorage or voyage in the world

Our Leak Test services

N t ti LT i (i K )

Our Leak Test services

New construction LT services (in Korea)• Ammonia Tightness Test• Primary Barrier Global Testy• Secondary Barrier Tightness Test• Helium Test & Global Test

In-service LT services (Globally)S d B i Ti ht T t & Gl b l T t• Secondary Barrier Tightness Test & Global Test(leaks by change of bonding condition on SB)

• Sonic leak test (hearing test to check major leak on SB)( g j )• Ultrasonic leak test using AE sensors (leaks on SB)• Infrared Thermographic Leak Test (leaks on SB)• Helium test (leaks on PB welding after a large repair)

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• Helium test (leaks on PB welding after a large repair)

Test PreparationTest Preparation

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Ammonia TestAmmonia Test

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Ammonia TestAmmonia Test

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Helium TestHelium Test

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Helium TestHelium Test

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Global Test for Primary & Secondary MembraneGlobal Test for Primary & Secondary Membrane

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Secondary Barrier Tightness TestSecondary Barrier Tightness Test

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Infrared Thermographic Leak Test for LNGCInfrared Thermographic Leak Test for LNGC

ITLT at the loaded condition during voyage (-160℃)

• Pressure at Normal Phase(IBS 5mbar / IS 10mbar)

• Pressure at Investigation(IBS 8~22mbar / IS 0~2mbar)

• Temperature(Cargo Tank ≤ -160 ℃)

• About 8 days for 4 tanks

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Main Set of Leak Test EquipmentMain Set of Leak Test Equipment

LTCR (LT Control Room / 4.5 tons) : 19LTCR (LT Control Room / 4.5 tons) : 19

Mini LTCU (LT control Unit) : 5

Pipe shuttle (4.5 tons) : 16

Helium detector : 7

AE workstation : 2

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LNGC of membrane type (GTT design)LNGC of membrane type (GTT design)

CS1 typeNO.96 typeMark III typeType

Structure

Invar 0.7mmInvar 0.7mmSUS 304L 1.2mmPrimary

Triplex bondingInvar 0.7mmTriplex bondingSecondary

▪ Vulnerable Primary

▪ Vulnerable Secondary

▪ Vulnerable Primary

▪Well-protected Secondary

▪Well-protected Primary

▪ Vulnerable SecondaryFeature

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Test procedure for No 96 typeTest procedure for No.96 type

T t Fl Ch t

Strength Test

Test Flow Chart

• To simulate the mechanical effect of liquid methane weight• Pumping to 800mb from A P and Visual Inspectiong

Bearing Test

• Pumping to -800mb from A.P, and Visual Inspection

• To verify membrane installed and check its bearing• Inject to -200mb from -800mb, and Visual Inspection

Mechanical Test • To identify any possible weak point of various welds types• Inject to +20mb → Maintain 30min. → Return to A.P : 3times

He + Dry air injection • Create vacuum down to -600mb and inject He 33% to +20mb• Check He concentration at sampling points

He Test• Admissible leakage rate : 9.3x10-7 Pa.m3/sec• Inspection Cond. : 20%(min.10%) He in space with +20mb• Travel speed of leak-test apparatus : 1m/min

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Test procedure for No 96 typeTest procedure for No.96 type

T t Fl Ch t

Repair

Test Flow Chart

• leaks ＞ 5; To be checked with He LT in all the repair areas• leaks ≤ 5; To be checked with PT and VBT

VBT & DPT

p

• Examination for large leak at -100mbar for 10 seconds • Examination for small leak at -550mbar for 30 seconds• Dye penetrant test at atmospheric pressure

leaks ≤ 5; To be checked with PT and VBT

Pre. Global Test

• Dye penetrant test at atmospheric pressure

• Vacuum creation down to -800mbs• Stabilization 12hours and monitoring 24 hours

Pressure Monitoring • Continuous observation of pressure and temperature• Keep -800mb for the following test and work in cargo tanks

Final Global Test• Same test procedure above applied to Secondary and Primary • Final global test after side opening closure (-800mb)

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Pressure control for No 96 typePressure control for No.96 typeHe Test Pressure Control

+20mbar

Maintain 30 min. Air+He Random Check

A.P

-200mbar

-600mbar

33% He

-800mbar

Strength Mechanica Air+He H li L k T t RepairR i GlobalBearing VBT

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StrengthTest

Mechanical

Air He Injection Helium Leak Test Repair

TestRepair Global Test

BearingTest VBT

Test procedure for Mark III typeTest procedure for Mark III type

T t Fl Ch t

N2 Drying • Extract the air and air humidity (RHspace≤60%)• Exhaust down to 800mbar then injection with dry N2 (at least 3 times)

Test Flow Chart

y g

Mechanical Test

• Exhaust down to -800mbar, then injection with dry N2 (at least 3 times)

• Detect a weld weaknesses by stressing it• Three successive cycles AP > +20mbar > AP

NH3+N2 Injection • Filling of IBS by mixture gas and filling of IS by N2• IBS at 20mb and IS at 25mb

RLP Reaction • Reference leaks must be properly sealed and covered with dye strip•To be successful NH3 test, All RLP should be reacted

Painting• Control of paint must be started with the following conditions-All RLPs should be reacted on above and under level or on single wall-NH3 concentration ≥1%, Membrane surface and air temperature ≥ 20oC RHin tank≤70%

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-Membrane surface and air temperature ≥ 20oC, RHin-tank≤70%


T t Fl Ch t

Official inspection • All of the membrane welding will be officially examined• Any doubtful indication will be repainted

Test Flow Chart

N2 Rinsing • Exhaust down to -800mbar, then rinse with N2 up to AP• NH3 concentration must be reduced down to 1000ppm

p • Any doubtful indication will be repainted

Repair • Lower or equal to 4 leaks per 1000m2 : VT, VBT, PT• Higher than 4 leaks per 1,000m2 : additional NH3 test

Vacuum Box Test

All th i t b ill b d

• Examination for large leak at -200mbar for 10 seconds • Examination for small leak at -500mbar for 30 seconds

• All the paint on membrane will be removed• During this activities, special care must be taken to avoidmembrane surface damage

Paint removal

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NH3 Test Pressure Control

N2 Drying NH3+N2 Mixture InjectionAP

essu

rePr

e

Mechanical Test N2 Rinsing-800mbar

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Time


Primary Barrier Global Test

• To check whether primary barrier walls are perfectly tight when the tanks are loaded

• To check whether the walls are still tight as compared with the previous test during the scaffolding removalwith the previous test during the scaffolding removal operations till the final tank fitting operations

• To confirm that the tank is still tight after closing of the side opening

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Vacuum Creation• -800mbar ± 5 % of IBS and IS• 4 hours from AP to -800mbar

Test Flow Chart / PBGT

Stabilization

4 hours from AP to 800mbar

• At least 1 hour

Pressure monitoring • During scaffolds removal• 24 hours pressure reading per each cycle

Every 10min / first hr , every 30min / following hr• Temperature reading : every hour

In tank (3 level), External (Trunk deck) Temp.

N2 Injection to A.P. • For membrane surface damage repair• When scaffolds removal job finished

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Primary Barrier Global Test Pressure Control

Closing of Side OpeningAP

ress

ure

Final TestReference TestPr

Primary Barrier Global Test / Cycle#1-Cycle#n-800mbar

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Time


Secondary Barrier Tightness Test

• Performed after completion of tanks construction, before the ship’s delivery

• Establishing a pressure difference between IBS and IS, g precording the variation of pressure difference

• Giving information about the global sealing property of secondary barrier of each tank

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T t Fl Ch t / SBTT

Vacuum Creation

Test Flow Chart / SBTT

• -530mb ± 5% in IS • 4hours from A P to -530mb

Stabilization • At least 1 hour at -530mb of IS

4hours from A.P. to -530mb

Stabilization At least 1 hour at 530mb of IS

P li i T t• Monitoring of Pressure decay : 5 hrs / a cycle

• Monitoring of Pressure decay : 12~14 hrs

Preliminary Test • Minimum 2 cycles without irregular pressure decay

Actual Testg y

or monitoring can be stopped at -300mb• Pressure reading : every 30 min. of IBS and IS • Temperature reading : every 30 min.

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Cargo tank, Cofferdam and external temp.


Secondary Barrier Tightness Test Pressure Control

AP

ure

Preliminary Test / Cycle#2 Actual TestPres

su

Preliminary Test / Cycle#1 Preliminary Test / Option

-530mbar

y y y p

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Time


SBTT(Rev.3) Acceptance Criteria of In-serviceSBTT(Rev.3) Acceptance Criteria of In service

Vacuum Decay Curve of IS Calculation of N.P.A (Air)

P(mbar)

N. P. A. =1.210×10-3 ×VIS

ASB×∆t

-300Where N.P.A. : Normalized porosity area in M2

ASB : Secondary barrier area of considered tank in M2

∆t Ti f i b t

-450∆t : Time of pressure rise between

-450 and -300 mbar in hours

VIS : free volume of secondary space in M3

t1 t2

CTC : Cumulative Thermal Cycles

Log.e(N.P.A.) = 0.3368Log.e(CTC)-1.65㎠

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T (hour)


SBTT(Rev.4) Acceptance Criteria of In-serviceSBTT(Rev.4) Acceptance Criteria of In service

Vacuum Decay Curve of IS • Actual Test : 14 hours monitoring

P(mbar)

• VDRM = 150 / (tf - ti ) (△P/14h)

-300

(△P/14h)

• VDRmax =

-45060 – {40 / [1+((CTC-0.7)x4)/40]}

• VDRN =

ti tf

N

42.18 x VDRM x (VIS/ASB) x Cgas

VDR ≤ VDRmax

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T (hour) VDRN ≤ VDRmax

www.sgs.comwww.sgs.com/NDT

CONTACTS INDUSTRIAL SERVICESCONTACTS INDUSTRIAL SERVICES

Leak Testing• Sangchul Lee Korea• Sangchul Lee, Korea

– Phone : +82 10 4572 2723 +82 10 4739 8738

– Email : [email protected]

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Tests d'Etancheite Sur Methaniers

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