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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Test PreparationTest Preparation
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Test PreparationTest Preparation
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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%
Test procedure for Mark III typeTest procedure for Mark III type
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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Test procedure for Mark III typeTest procedure for Mark III type
NH3 Test Pressure Control
N2 Drying NH3+N2 Mixture InjectionAP
essu
rePr
e
Mechanical Test N2 Rinsing-800mbar
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Time
Test procedure for Mark III typeTest procedure for Mark III type
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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Test procedure for Mark III typeTest procedure for Mark III type
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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Test procedure for Mark III typeTest procedure for Mark III type
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
Test procedure for Mark III typeTest procedure for Mark III type
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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Test procedure for Mark III typeTest procedure for Mark III type
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.
Test procedure for Mark III typeTest procedure for Mark III type
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
Test procedure for Mark III typeTest procedure for Mark III type
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)
Test procedure for Mark III typeTest procedure for Mark III type
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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