shell rbi methodology
DESCRIPTION
risk based inspection by Shell Global SolutionsTRANSCRIPT
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1 Shell Global SolutionsP-B-v1.1
Shell Global SolutionsShell Global Solutions
S-RBISHELL RISK-BASED INSPECTION
- THE METHODOLOGY -
Risk and Reliability Management
Presenter: Maarten FestenBUSINESS GROUP
MAINTENANCE, INSPECTION AND RELIABILITY ENGINEERING
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2 Shell Global SolutionsP-B-v1.1
S-RBI: SHELL RISK-BASED INSPECTION
S-RBI Work flow
in the RRM software S-RBI methodology
part of RRM Manual, issued in 1999
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3 Shell Global SolutionsP-B-v1.1
S-RBI AS PART OF RISK ANDRELIABILITY MANAGEMENT (RRM)
methodologymethodologyandand
databaseRRMRRM
database
SS--RBIRBI SS--RCMRCM IPFIPFSHELL RSHELL Reliability
CCentered MMaintenanceIInstrumentedPProtective FFunctions
(safeguarding systems)
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4 Shell Global SolutionsP-B-v1.1
S-RBI PROCESS
ASSET INTEGRITYDATABASE
CORROSION LOOPDESCRIPTIONS
CRITICALITYASSESSMENT
CONFIDENCEASSESSMENT
INSPECTION/MONITORINGPLANNING
S
-
R
B
I
P
A
C
K
A
G
E
ANALYSIS/REVIEWFEEDBACK
TASK EXECUTION
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5 Shell Global SolutionsP-B-v1.1
THE ADVANTAGES OF SINGLE RRM DATABASE FOR RBI/RCM/IPF ANALYSES
COMMON USE OF RESOURCE DATA
pick lists for e.g. equipment types, materials etc. Consequence of Failure analysis/data
STANDARD CRITICALITY DEFINITION
1 Criticality Matrix in line with HSE standard (RAM, April 1999)
TASKS FOR EACH ITEM DEFINED ON SAME CRITERIA
tasks can be compared & optimised
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6 Shell Global SolutionsP-B-v1.1
RBI STUDIES - RRM DATABASE
PREPARATION, WHERE POSSIBLE BEFORE THE STUDIES:
Common part can be filled
or used from S-RCM or IPF, if already carried out Assets can be filled
or used from S-RCM or IPF, if already carried out Inspection information can be entered
one liners, giving relevant information only
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7 Shell Global SolutionsP-B-v1.1
RBI STUDY - TEAM SESSIONS
Review plant data, former and future operating conditions (where applicable)
Discuss materials selection and inspection experience
Develop Corrosion Loops and Operating Windows
Do criticality analysis
List confidence rating
Develop inspection/monitoring scope
mainly by inspection & corrosion members, team review
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8 Shell Global SolutionsP-B-v1.1
Shell Global SolutionsShell Global Solutions
S-RBI METHODOLOGY
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9 Shell Global SolutionsP-B-v1.1
SIMPLIFIED S-RBI FLOW CHART (1)
NO
YES
INTOLERABLE
RECTIFY
MediumHigh
ExtremeNegligible Low
Asset Integrity Database
Review operating conditionsand Materials Selection
Corrosion Loops
LoopCriticality
Assessment
LoopCriticalityNegligible
No inspectionReview only
RCM
EquipmentItem
ItemCriticality
Inspection/Monitoring
Interval & Scope
Analysis &Feedback
1
Inspection /Monitoring
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10 Shell Global SolutionsP-B-v1.1
CORROSION LOOPS
DIVIDE THE UNIT IN CORROSION LOOPS
Discuss the process parameters
Review materials applied
Highlight inspection/degradation history
Discuss Materials Engineering issues/experience (generic)
Divide the unit in Corrosion Loops (colouring PFS schemes)
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11 Shell Global SolutionsP-B-v1.1
S-RBI IS BASED ON CORROSION LOOPS
CORROSION
WHAT TYPE OF DEGRADATION CAN OCCUR AND WHERE ?
MATERIAL+
ENVIRONMENT
WHICH (PROCESS) CONTROLSARE NEEDED ?
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12 Shell Global SolutionsP-B-v1.1
WHAT IS A CORROSION LOOP?
A PRACTICAL WAY TO DESCRIBE, UNDERSTAND AND CHECK DEGRADATION MECHANISMS IN A UNIT
PART OF THE UNIT SUBJECTED TO: the same process conditions the same failure mechanisms the same materials selection
criteria ONE OPERATING WINDOW control of degradations via
process control values agreed by team
(boundary conditions for RBI) deviation should be reported
12-E-101
1
2
-
D
-
1
0
1
12-G-101
12-K-1011st stage
12-E-102
to burn pit
Loop 1
Loop 2
Loop 3
CORROSION LOOP
same process conditions same degradation mechanisms
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13 Shell Global SolutionsP-B-v1.1
CORROSION LOOPS FOR A KERO HDT
Product toStripper
Sour Water
Recycle Hydrogen
Hydrogen from Platformer
To Fuel Gas systemCTW5Cr 0.5Mo
321 SSas sscs cs cs as
Feed fromCDU
R-1201
E-1202
ABCDEF
E-1201
CSCS
CSCS
1.25Cr 0.5Mo
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14 Shell Global SolutionsP-B-v1.1
EXPERIENCE WITH CORROSION LOOPS
Applied in refineries, chemical plants and gasplants
Good experience and part of S-RBI approach
Useful to set operating windows
Information on degradation mechanisms (and affected areas)
Info on degradation available for all staff concerned with integrity!
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15 Shell Global SolutionsP-B-v1.1
CRITICALITY ASSESSMENTFOR THE CORROSION LOOP: Stop if Negligible Criticality or Negligible Consequence of Failure
is obtained (no further analysis on item by item basis) these items are analysed by S-RCM to optimise maintenance
plans and in a review scheme for RBI (checking if changes occurred)
FOR INDIVIDUAL ITEMS: Carry out the criticality rating for each item can be grouped for similar piping items into e.g. LP piping can be divided into 2 loops, e.g. Column top,
and Column bottom
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16 Shell Global SolutionsP-B-v1.1
SIMPLIFIED S-RBI FLOW CHART (2)
NO
YES
INTOLERABLE
RECTIFY
MediumHigh
ExtremeNegligible Low
Asset Integrity Database
Review operating conditionsand Materials Selection
Corrosion Loops
LoopCriticality
Assessment
LoopCriticalityNegligible
No inspectionReview only
RCM
EquipmentItem
ItemCriticality
Inspection/Monitoring
Interval & Scope
Analysis &Feedback
1
Inspection /Monitoring
2
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17 Shell Global SolutionsP-B-v1.1
CRITICALITY MATRIX
HIGHNEGLIGIBLES-RBI LOWMED
IUMEXTENSIVE
NNNEGLI-GIBLE NN LL MM HHNNLOW LL MM HH EELLMEDIUM MM HH EE XXLLHIGH HH EE XX XX
CONSEQUENCES
P
R
O
B
A
B
I
L
I
T
Y
NEGLIGIBLENEGLIGIBLENO INSPECTIONREVIEW ONLY
INTOLERABLEINTOLERABLE
LOWLOWMEDIUMMEDIUM
HIGH CRITICALITYHIGH CRITICALITY
INSPECTION PLAN
RECTIFY
EXTREMEEXTREMECRITICALITYCRITICALITY
DETAILED ANALYSIS
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18 Shell Global SolutionsP-B-v1.1
SUSCEPTIBILITY TO FAILUREINSTEAD OF PROBABILITY The Susceptibility to Failure (StF) is the worst case estimate for the
degradation under consideration, without corrective actions(no inspections, no monitoring).
The StF will lead to the Criticalty of the items in combination with the Consequence of Failure (CoF).
After implementation of monitoring & inspection, the remaining possibility that such a degradation leads to an incident is described as the Probability of Failure (PoF); together with CoF this describes the remaining Risk in operation.
The PoF must be As Low As Reasonably Possible (ALARP) and not exceed Low in general, and
Negligible where the CoF is Medium, High or Extreme
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19 Shell Global SolutionsP-B-v1.1
CRITICALITY RATING
Determine the Susceptibility to Failure (StF)
Determine the Consequence of Failure (CoF)
Combination of StF and CoF yields the Criticality
CRITICALITY = potential riskwithout preventive measures or corrections
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20 Shell Global SolutionsP-B-v1.1
RBI CRITICALITY MATRIX (1)
N LL MM
E
H
XEH
HMM
MMLL
LL
N
N
XXEHLL3
2
1
4
P
R
O
B
A
B
I
L
I
T
Y
C
L
A
S
S
MULTIPLEFATALITIES
EXTENSIVEDAMAGE >10M
SLIGHT INJURY
SLIGHT DAMAGE
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21 Shell Global SolutionsP-B-v1.1
RBI CRITICALITY MATRIX (2)
N LL MM
E
H
XEH
HMM
MMLL
LL
N
N
XXEHLL3
2
1
4
P
R
O
B
A
B
I
L
I
T
Y
C
L
A
S
S
MULTIPLEFATALITIES
EXTENSIVEDAMAGE >10M
SLIGHT INJURY
SLIGHT DAMAGE
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22 Shell Global SolutionsP-B-v1.1
Shell Global Solutions
SUSCEPTIBILITY TO FAILURE ASSESSMENT
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SUSCEPTIBILITY TO FAILURE (STF) (1)
Determine potential degradation mechanisms for the Loop.
For those degradation mechanisms, identify the StF per item.
for each item since there can be differences in temperature etc..
For each item, analyse the different degradation mechanisms separately since they may result in different failure modes.
Different inspection techniques/intervals may be required.
Monitoring scheme to be indicated for non-age realateddegradations.
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24 Shell Global SolutionsP-B-v1.1
SUSCEPTIBILITY TO FAILURE (STF) (2)
The failure mode will influence the Consequence of Failure and therefore the Criticality.
The item criticality will be the highest rating of all failuremodes.
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25 Shell Global SolutionsP-B-v1.1
SUSCEPTIBILITY TO FAILURE (STF) (3) AGE RELATED DEGRADATIONS time factor (very) important in relation to degradation degradations can be foreseen/predicted and controlled
general corrosion (thinning) creep
part of normal design criteria, basis for design life
NON-AGE RELATED DEGRADATIONS time factor not important in relation to degradation degradations can be fast often related to plant upsets
e.g. stress corrosion cracking due to Cl or caustic brittle failure not acceptable, not in normal designs;
special precautions/controls needed
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26 Shell Global SolutionsP-B-v1.1
FAILURE MODES
Time
Time
Tim
AGE-RELATED NON-AGE-RELATED
4
5
6
1
2
3
Time
Time
Time
Time
Time
P
o
F
P
o
F
P
o
F
P
o
F
P
o
F
P
o
F
internal/external corrosion creep
Random failures
Failures are mostlyrandom with only afew early-life failures
More failures occurshortly after installation,repair or overhaul
Time
P
o
F
?
SCC due to a Process upset
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27 Shell Global SolutionsP-B-v1.1
SUSCEPTIBILITY OF FAILURESUSCEPTIBILITY OF FAILURE
DEGRADATION MODULESDEGRADATION MODULES
failure characteristic:non age-related
THINNING
- CRACKING- H-ATTACK- MECHANICALCREEP
determinefailure characteristic
failure characteristic:age-related
determine susceptibilitybased on the ratio:
actual corrosion rate/design corrosion rate
determine Susceptibilitybased on
API Technical ModulesFitness for Service study
determine susceptibilitybased on the
operating conditions
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28 Shell Global SolutionsP-B-v1.1
StF - AGE-RELATED DEGRADATIONS1 Internal Corrosion The actual corrosion rate is very high (e.g. > 4 CRd) H
General and/or localised The actual corrosion rate is high (e.g. 1 - 4 CRd) MThe actual corrosion rate is acceptable/low (e.g. 0.5 - 1.0 CRd) LThe actual corrosion rate is very low (e.g. < 0.5 CRd) N
2 External Corrosion Severe external corrosion ( e.g. 60 -120 C with high humidity and/orspray, condense, cycling conditions, damaged insulation)
H
Corrosion underinsulation
Serious external corrosion , (e.g. -5 to 60 C or 120 - 150 C andhumid climate, damaged insulation)
M
Minor external corrosion under normal operating conditions(0.05mm/yr) L
No foreseeable external corrosion (not insulated or >150 C) N3 Creep Operation in the creep range, risk of major upsets which must be
quantified in terms of remnant lifeH
Operation in the creep range, risk of minor upsets which must bequantified in terms of remnant life
M
Operation in the creep range at or below design conditions L
No foreseeable operation in the creep range N
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29 Shell Global SolutionsP-B-v1.1
SUSCEPTIBILITY TO FAILURE INTERNAL CORROSIONgeneral & localized corrosion
0.5 - 1 x design CR
< 0.5 x design CR
Corrosion Rating for Susceptibility to Failure
RRM MATRIX
H igh
M edium
L ow
N egligible
> 4 x design CR
>1 - 4 x design CR
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30 Shell Global SolutionsP-B-v1.1
StF - NON AGE-RELATED DEGRADATIONS (1)4 Fatigue - Thermal Cyclic temperature range or delta T of two process streams greater than 250 C H Cyclic temperature range or delta T of two process streams between 150 and
250 C M
Cyclic temperature range or delta T of two process streams between 100 and 150 C
L
All other lines or equipment N
5 Fatigue - Vibrations Vibrating in zone 1, or nominal pipe diameter less than 50 mm and in zone 2 and 3
H
Vibrating in zone 2, or nominal pipe diameter between 50 and 100 mm and in zone3
M
Vibrating in zone 3 L
No foreseeable fatigue due to vibration (zone 4 or no vibrations N
6 Stress Corrosion Cracking High susceptibility H
External or internal Medium susceptibility M
Low susceptibility L
Not susceptible N
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CAUSTIC CRACKING MODULEAPI 581 and degradation library
Start
Plot Point on NACECaustic SodaService Graph
Medium Susceptibility
Yes
No
No
Yes
Yes
Yes
No
TemperatureNaOHConcentration
Heattraced?
No
Medium Susceptibility
Not Susceptible
Yes
Steamedout?
No
Heattraced?
No
Not Susceptible
Yes
Yes
High SusceptibilityNo
H
NaOHconc
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32 Shell Global SolutionsP-B-v1.1
StF - NON AGE-RELATED DEGRADATIONS (2)
NAR 7 Low Temp. Embrittlement Operating or upsets outside the limits of DEP 30.10.02.31Gen.
H
(No cat. M)
Operating or upsets within the limits of DEP 30.10.02.31Gen.
L
Not susceptible under any foreseeable conditions N
NAR 8 High Temp. Embrittlement Operating in the embrittlement range and no S/Dprecautions
H
Design or upsets in the embrittlement range and no S/Dprecautions
M
Design and operation below the embrittlement range or S/Dprecautions
L
Not susceptible under any foreseeable conditions N
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33 Shell Global SolutionsP-B-v1.1
StF - NON AGE-RELATED DEGRADATIONS (3)
NAR 9 High TemperatureHydrogen Attack
Operating/upset conditions above the Nelson curve limit(API 941)
H
Operating conditions between the Nelson curve limitand 20 C below (API 941)
M
Operating conditions are 20 - 50 C belowthe Nelson curve limit (API 941)
L
Operating conditions are > 50 C below the Nelson curvelimit (API 941) or Material is not susceptibleunder any foreseeable conditions
N
NAR 10 Erosion Flow velocity is much higher than design and/or much largeramounts of solids/droplets present
H
(non protected system) Flow velocity is higher than design, and/or solids/dropletshigher than design
M
Flow velocity is per design or less, solids/droplets loading asper design or less
L
No foreseeable occurrence of erosion N
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34 Shell Global SolutionsP-B-v1.1
StF - DEGRADATION MODULESfor further information
Based on the API BRD 581 Technical Modules
modified where required to reflect SIOP experience 15 Modules available for all major degradation mechanisms
(and more under development)
general corrosion acids water etc.
CUI, H2S, H2 attack, SCC, etc.
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Shell Global Solutions
CONSEQUENCE OF FAILURE (CoF) ASSESSMENT
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36 Shell Global SolutionsP-B-v1.1
CONSEQUENCE OF FAILURE ASSESSMENT
PURPOSE IS TO ESTIMATE CONSEQUENCE CLASS (1 OUT OF 5)
THREE LEVELS OF ASSESSMENT ARE AVAILABLE
1 Direct selection (using Risk Assessment Matrix - RAM)
2 Simple questionnaire using RAM descriptions,but split over important aspects of each category
3 Detailed questionnaire, using relevant processand equipment data
USE TOP-DOWN APPROACH
Use 3 to set the levels for the loop, for main items
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37 Shell Global SolutionsP-B-v1.1
DIRECT ASSESSMENT OFCONSEQUENCE OF FAILURE
>10 M$SUBSTANTIAL/TOTAL LOSS OF
OPERATION
MULTIPLEFATALITIES
MASSIVE EFFECTSEVERE DAMAGE
NUISANCE INLARGE AREA
1 - 10 M$PARTIAL
OPERATIONLOSS (2 WEEKS)
SINGLE FATALITYINCLUDING
PERMANENT TOTAL DISABILITY
MAJOR EFFECTEXTENSIVE
RESTAURATIONREQUIRED
0.1 - 1 M$PARTIAL
SHUTDOWNCAN BE RESTARTED
MAJOR INJURYINCLUDINGPERMANENT
PARTIAL DISABILITY
LOCALISED EFFECTAFFECTING
NEIGHBOURHOOD
10 - 100 k$BRIEF DISRUPTION
MINOR INJURYLOST TIMEINCLUDED
MAXIMUM 1 WEEK
MINOR EFFECTCONTAMINATION,NO PERMANENT
EFFECT
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38 Shell Global SolutionsP-B-v1.1
ECONOMICS
PRODUCTION LOSS
deferred income (no or downgraded product)
product wasted (flared or spilled)
REPAIR COSTS
repair/re-install item
fixed contractor costs (lump sum)
LABOUR
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39 Shell Global SolutionsP-B-v1.1
DIRECT ASSESSMENT OFECONOMIC CONSEQUENCES
Class Potential Impact Description
N Slight damage< 10 kUSD
No disruption to operation
L Minor damage10-100 kUSD
Brief disruption
M Local damage0.1-1 MUSD
Partial shutdown that can berestarted
H Major damage1 - 10 MUSD
Partial operation loss (2 weeksshutdown)
E Extensive damage> 10 MUSD
Substantial or total loss ofoperation
definitions as given in the HSE RAM
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40 Shell Global SolutionsP-B-v1.1
ECONOMIC CONSEQUENCESsimple questionnaire
1
2
3
6
COSTELEMENT
Production loss k
Repair costs k
Labour k
Total k
Economic consequence class: N
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41 Shell Global SolutionsP-B-v1.1
PRODUCTION LOSS EQUATIONProduction lossesDown time 6 hr = 100 kUSD
Reduced throughput 5 hr @ 20 % = 50 kUSD
Miscellaneous = 30 kUSD
Total production losses 180 kUSD
Repair costsMaterials / Equipment = 10 kUSD
Fixed contractor costs = 4 kUSD
Miscellaneous = 0 kUSD
Total repair costs 14 kUSD
LabourCraftsmen 5 hr = 300 USD
Operator 4 min = 7.2 USD
Staff 1 hr = 80 USD
Contractor 2 hr = 100 USD
Total labour 0.487 kUSD
Total economic consequence 194.487 kUSD
Economic consequence class M
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42 Shell Global SolutionsP-B-v1.1
STAGGERED PRODUCTION LOSS EQUITION
0
20
40
60
80
100
0 5 10 15Time [h]
L
o
s
s
[
k
U
S
D
]
PLE example:0 - 2 h: 2 kUSD/h2 - 8 h: 4 kUSD/h> 8h : 8 kUSD/h
t1 t2
22
88
In software 2 and 8 should be entered asthe inputs with the loss value up to that limit
5 periodscan bedefined
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43 Shell Global SolutionsP-B-v1.1
HEALTH AND SAFETY Three health and safety effects are considered:
1 Thermal effect (fire) 2 Blast and fragment (explosion)3 Toxic effect
which can be reduced by mitigation
Maximum of three minus mitigation is overallHealth and Safety class
Simple questionnaire connects the degree of hazard toHealth and Safety descriptions
e.g. medium fire which could cause minor injuries
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44 Shell Global SolutionsP-B-v1.1
HSE RAM DEFINITIONSTable 3-2 Health/Safety consequence definitions as given in the HSE RAMdocument
Class Potential Impact Description
N No/Slight injury First aid case and medical treatment case. Not affectingwork performance or causing disability.
L Minor injury Lost time injury. Affecting work performance, such asrestriction to activities or a need to take a few days to fullyrecover (maximum one week).
M Major injury Including permanent partial disability. Affecting workperformance in the longer term, such as prolonged absencefrom work. Irreversible health damage without loss of life,e.g. noise induced hearing loss, chronic back injuries.
H Single fatality Also includes the possibility of multiple fatalities (maximum3) in close succession due to the incident, e.g. explosion.
E Multiple fatalities May include 4 fatalities in close succession due to theincident, or multiple fatalities (4 or more) each at differentpoints and/or with different activities.
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45 Shell Global SolutionsP-B-v1.1
HEALTH & SAFETYsimple questionnaire (1)
CONSEQUENCECLASS
CONSEQUENCE DESCRIPTION
FIREFailure mode leads to:
1 N No fire or fire which could only cause slight injuries (no LTI)2 L Fire which could cause minor injuries (LTI)3 M Fire which could cause major injuries (LTI> 1 week and/or partial disability)4 H Fire causing up to a single fatality or permanent total disability
EXPLOSIONFailure mode leads to:
1 N No explosion but just a flash fire which could only cause slight injuries (first aid)2 L No explosion but a flash fire which could cause minor injuries (LTI)3 M Explosion or flash fire which could cause major injuries (LTI>1week and/or
partial disability)4 H Explosion or flash fire which could cause a single fatality or permanent total
disability5 E Explosion which could cause multiple fatalities
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46 Shell Global SolutionsP-B-v1.1
HEALTH & SAFETYsimple questionnaire (2)
CONSEQUENCECLASS
CONSEQUENCE DESCRIPTION
TOXICFailure mode leads to:
1 N No or very small toxic release which could cause only slight injuries (first aid)2 L Small toxic release which could cause minor injuries (LTI)3 M Medium toxic release which could cause major injuries (LTI>1week and/or
partial disability)4 H Large toxic release which could cause a single fatality or permanent total
di bilit5 E Very large toxic release which could cause multiple fatalities
MITIGATIONExposure near failure location and possibility to avert danger of hazardousevent could reduce possible H/S consequence class by:
0 No means or only marginally-1 One class-2 Two classes
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47 Shell Global SolutionsP-B-v1.1
HEALTH & SAFETYdetailed questionnaire
Table 3-4 Common consequence matrix
4 N H E E
quantity 3 N M H E
2 N L M H
1 N N L M
1 2 3 4
property
flammability
quantityreleased
For fires
Consequenceof FailureNegligible toExtreme
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48 Shell Global SolutionsP-B-v1.1
HEALTH AND SAFETYfire Two parameters are used to estimate fire consequence:
Flammability NFPA (National Fire Protection Association)
flammability index, 0 Nf 4 and temperature Released quantity (instantaneous/per hour/inventory)
three levels: < 500 kg, 0.5 - 5 ton, and > 5 ton
Matrix to determine fire class (Max H)
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49 Shell Global SolutionsP-B-v1.1
FIREdetailed H & S questionnaire
Nf Products
0 Sulphur Diox ide, SodiumChloride
1 Sulphur, Am m onia
2 Diesel Fuel, Fuel O il 1 to 6
3 Gasoline, Naphtha, EthylAlcohol, Petroleum Crude
4 Hydrogen, Methane,Hydrogen Sulphide
Table 3-6 Fire safety questionnaire
Flammability
1 Not flammable (Nf < 2) or lowflammability (Nf >1 and Tproduct < Tflash)
2 Medium flammability(Nf > 1 and Tflash < Tproduct < Tauto ign)
3 High flammability(Nf > 1 and Tproduct > Tauto ign)
Released quantity(instantaneous or per hour or inventory)
1 < 500 kg
2 0.5-5 ton
3 > 5 ton
released 3 N M H
quantity 2 N L M
1 N N L
1 2 3
flammability
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RELEASE OF LIQUID THROUGH A HOLE
1
10
1 10 100pressure [barg]
h
o
l
e
d
i
a
m
e
t
e
r
[
m
m
]
505005000
5 mm
advised as theaverage case, results
in released Q=2
kg/h
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HEALTH AND SAFETYexplosions
TWO EXPLOSION/IMPACT RISKS ARE CONSIDERED:1 Vapour Cloud Explosions (VCE) VCE possibility (flammable cloud and congested area) released vapour mass (instantaneous, per hour) matrix to determine VCE class
2 Other impact/high pressure risks high pressure equipment failure causing flying debris
MAXIMUM OF THE TWO IS EXPLOSION CLASS (MAX E)
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52 Shell Global SolutionsP-B-v1.1
EXPLOSIONdetailed H & S questionnaire Table 3-7 VCE consequence questionnaire
VCE possibility
1 None; no release of anexplosive cloud
2 Low; release of an explosivecloud in an open area
3 Medium; release of an explosivecloud in a medium congestedarea (some obstacles present)
4 High; release of an explosivecloud in a heavily congestedarea (many obstacles present)
Released vapour mass(instantaneous or per hour)
1 < 50 kg
2 50 - 500 kg
3 0.5 - 5 ton
4 > 5 ton
released 4 N H E E
vapour 3 N M H E
mass 2 N L M H
1 N N L M
1 2 3 4
VCE possibility
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53 Shell Global SolutionsP-B-v1.1
RELEASE OF GASthrough a 3 mm hole C1-C2 and H2
10
100
1000
0 50 100 150 200 250Pressure [bara]
R
e
l
e
a
s
e
r
a
t
e
[
k
g
/
h
]
C1-C2 (@ 50 C)H2 (@ 50 C)
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54 Shell Global SolutionsP-B-v1.1
RELEASE OF LPG THROUGH A 3 MM HOLE
0
500
1000
1500
2000
2500
0 50 100 150 200 250Pressure [bara]
R
e
l
e
a
s
e
d
q
u
a
n
t
i
t
y
[
k
g
/
h
]
C3 @ 50 CC3 @ 100 CC4 @ 50 CC4 @ 100 C
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55 Shell Global SolutionsP-B-v1.1
EXPLOSION & HPdetailed H & S questionnaire
Table 3-8 Other explosion and high pressure equipment consequence questionnaire
N no gas present or p*V500 bar m3 or failure causing some flying debris (solid particles)
E failure causing major flying debris (solid particles)
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56 Shell Global SolutionsP-B-v1.1
HIGH PRESSURE CONSEQUENCE OF GAS PIPES
0.1
1
10
1 10 100pressure [barg]
p
i
p
e
d
i
a
m
e
t
e
r
[
m
]
550500
P x Vbar m3
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57 Shell Global SolutionsP-B-v1.1
HEALTH AND SAFETYtoxic effects
TWO PARAMETERS DETERMINE TOXIC CONSEQUENCE: Toxicity
NFPA health index, 0 Nh 4 Concentration
four levels: < 1000 ppm, , > 10%
MATRIX TO DETERMINE TOXIC CLASS (MAX E)
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58 Shell Global SolutionsP-B-v1.1
Table 3-9 Toxicity index, Nh, examples
Nh Products
0 Diesel
1 Butane, Gasoline
2 CO, benzene,Ethylene Oxide
3 H2S, chlorine, Ammonia,Sulphuric Acid, Phenol
4 Hydrogen Fluoride (HF),Hydrogen Cyanide
Table 3-10 Toxic consequence questionnaire
Toxicity
1 Not toxic (Nh1) or low toxicity(Nh3 and conc. < 100 ppm).
2 Medium toxicity (Nh=2)
3 High toxicity (Nh=3)
4 Extreme toxicity (Nh>3)
4 N H E E
Concentration (in ppm or % volume) Concentration 3 N M H E
1 < 1000 ppm 2 N L M H
2 < 10 000 ppm (or < 1%) 1 N N L M
3 1-10 % 1 2 3 4
4 > 10 % Toxicity
TOXIC RELEASESdetailed H & S questionnaire
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59 Shell Global SolutionsP-B-v1.1
HEALTH AND SAFETYmitigation
TWO FACTORS DETERMINE MITIGATION:
1 Exposure
Frequency of and exposure time in hazardous zone2 Possibility to avert the hazardous situation
Depends on: rate of development, ease of recognition, avoidance of exposure, use of ppe, experience.
MATRIX TO DETERMINE OVERALL REDUCTION(0, 1 or 2 classes)
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60 Shell Global SolutionsP-B-v1.1
MITIGATIONdetailed H & S questionnaire
Possibility 3 -1 0 0
to avert 2 -1 -1 0
danger 1 -2 -1 -1
1 2 3
Exposure
Table 3-11 Mitigation questionnaire
Exposure
1 Very rare(less than 10 man-minutes per day)
2 Occasionally(less than 6 man-hours per day)
3 Frequently to continuously(more than 6 man-hours per day)
Possibility to avert danger
1 In almost all circumstances
2 In some circumstances(more than 25% of cases)
3 Not (or hardly possible)
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61 Shell Global SolutionsP-B-v1.1
ENVIRONMENT
TWO EFFECTS ARE CONSIDERED:
1 Liquid spills (max E) toxicity Released quantity (or inventory) location (within / outside fence) surface (possibility to reach surface and/or ground water
2 Gas emissions (max M) Type (volume and how harmful) Effects (complaints)
MAXIMUM OF TWO IS ENVIRONMENT CLASS
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62 Shell Global SolutionsP-B-v1.1
ENVIRONMENTALsimple questionnaire
Table 3-13 Simple environment questionnaire
Severityrating
Consequence description
Liquid spillsFailure mode leads to a liquid spill with:
1 N No or negligible environmental damage2 L Minor environmental damage3 M Localised environmental damage4 H Major environmental damage5 E Massive environmental damage
Gas emissionFailure mode leads to:
1 N No or small harmful release2 L Small harmful release leading to many complaints or large3 M Large harmful release leading to many complaints
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63 Shell Global SolutionsP-B-v1.1
ENVIRONMENTALdetailed questionnaire
Table 3-14 Liquid spills questionnaire
Environmental toxicity
1 Not harmful to environment (e.g.water)
2 Harmful but not toxic(e.g. most alkanes)
3 Harmful and toxic(e.g. drins)
4 N H E
Released quantity ( or inventory) 3 N M H
1 < 500 kg Quantity 2 N L M
2 0.5 - 5 ton 1 N N L
3 5 - 50 ton 1 2 3
4 > 50 ton Toxicity
Location0 Contamination remains inside fence1 (Part of) contamination is outside fence
Surface of spill0 No chance that spilled liquids will reach
outside fence surface or ground water1 There is a possibility that spilled liquids will
reach outside fence surface or ground water
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64 Shell Global SolutionsP-B-v1.1
ENVIRONMENTALdetailed questionnaire
Table 3-15 Gas emission questionnaire
Type of release3 large (> 1000 normal m3 ) and harmful2 small and harmful1 other
Effect1 No or few complaints2 Many complaints or is to be reported to the Authorities.
Type of 3 L MRelease 2 N L
1 N N
1 2Effect
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65 Shell Global SolutionsP-B-v1.1
DETERMINATION OF THECONSEQUENCE OF FAILURE - Summary
DIRECT
SIMPLE QUESTIONNAIRE
compliant with HSE descriptions DETAILED QUESTIONNAIRE
provide guidance and consistency useful if limited HSE experience is available mechanistic keep thinking seek specialist advice in cases of doubt or high criticality
-
66 Shell Global SolutionsP-B-v1.1
DETERMINE INSPECTION SCOPEDETERMINE FAILURE
CHARACTERISTIC
FAILURE CHARACTERISTIC:
AGE-RELATEDFAILURE CHARACTERISTIC:
NON AGE-RELATED
- CRACKING- H-ATTACK
- MECHANICALCREEP
MONITORING= TABLE
MAX. INSP. INTERVAL= RL X INTERVAL FACTOR
Determine Susceptibilitybased on the ratio: Actual corrosion
rate/design corrosion rate
Determine Susceptibilitybased on API Technical
Modules Fitness for Service study
Determine Susceptibilitybased on the
operating conditions
THINNING StFHMLN
CoFEHMLN
CRITICALITY
CONFIDENCERATING
ADVISED METHODS AS PER DEGRADATION MODULE,EXTENT PER CRITICALITY LEVEL
ADVISED MONITORING BASED ON DEGRADATION MODULE,EXTENT PER CRITICALITY LEVEL
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67 Shell Global SolutionsP-B-v1.1
CONFIDENCE RATING
INDICATOR FOR CONFIDENCE IN FORECAST OF DEGRADATION
RATING - very low to very high REFLECTS: stability/predictability of degradation number and quality of previous inspections process stability
BETTER CONFIDENCE YIELDS LONGER INSPECTION INTERVALS
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68 Shell Global SolutionsP-B-v1.1
CALCULATION OF INSPECTION INTERVALfor age-related degradations
consequence of failure(questionnaire)
susceptibility tofailure (questionnaire)
- inspection records- experience- judgement
matrix
CONFIDENCERATING
matrix
CRITICALITY
corrosion allowancecorrosion rate
REMNANT LIFE Xmultiply
INTERVAL FACTOR
MAXIMUM INSPECTIONINTERVAL (in years)
MAXIMUM INSPECTIONINTERVAL (in years)
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69 Shell Global SolutionsP-B-v1.1
AGE-RELATED DEGRADATION - inspection interval factor function of Criticality and Confidence Rating
Criticality Interval FactorE 0.2H 0.3M 0.4L 0.5N 0.6
Confidence Rating Adjustment factorVH - Very high + 0.2H - High + 0.1M - Medium 0L - Low -0.1VL - Very Low -0.2
Description ScoreYES Int. NO
Degradation mechanism is stable and properly controlled + 0.1 0 -0.1Multiple reliable inspections have been carried out + 0.1 0 -0.1Relevant process parameters are reliably monitored + 0.1 0 0
Inspection Interval Factor forMedium Confidence Rating
add orsubtract
add/subtractto/fromMEDIUMSCORE
Adjustment of interval factorbased on Confidence Rating
Scoring points for adjustment factor withmedium confidence as starting point. Maximum adjustment +/- 0.2
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70 Shell Global SolutionsP-B-v1.1
INTERVAL FACTORSfor age-related degradations
CONFIDENCE RATING
CRITICALITY Very Low Low Medium High Very High
E
H
M
L
N (review only)
0 0.1 0.2 0.3 0.4
0.1 0.2 0.3 0.4 0.5
0.2 0.3 0.4 0.5 0.6
0.3 0.4 0.5 0.6 0.7
0.4 0.5 0.6 0.7 0.8
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71 Shell Global SolutionsP-B-v1.1
MAXIMUM INSPECTION INTERVAL
XX
LIFETIME IN YEARS
INSPECTIONS
X
WALLTHICKNESS
MINIMUM ALLOWABLE THICKNESSt (min)
t new REMNANT LIFE
MAXIMUM INSPECTIONINTERVAL
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72 Shell Global SolutionsP-B-v1.1
INSPECTION COVERAGE (PERCENTAGE)age-related degradation
CONFIDENCE RATINGCRITICALITY VERY LOW LOW MEDIUM HIGH VERY HIGH
REDESIGNINTOLERABLE80-100%EXTREME
25-100%HIGH5-25%MEDIUM
5-25%LOWNEGLIGIBLE 0-5%
SELECTION OF PROPER NDT-TECHNIQUEVIA SHELL NDT HANDBOOK
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73 Shell Global SolutionsP-B-v1.1
MONITORING SCHEMEfor non age-related degradations
consequence of failure(questionnaire)
susceptibilityto failure (questionnaire)
ACCEPTABLE?
IMPLEMENTMONITORING PROCESS
MONITORING OPPORTUNITY
INSPECTIONS
YESmatrix
NOREDESIGN PROCES DESIGN MECHANICAL DESIGN
matrix
CONFIDENCERATINGCRITICALITY
-
74 Shell Global SolutionsP-B-v1.1
N LL MM
E
H
XEH
HMM
MMLL
LL
N
N
XXEHLL3
2
1
4
P
R
O
B
A
B
I
L
I
T
Y
C
L
A
S
S
MULTIPLEFATALITIES
EXT. DAMAGE>10M
SLIGHT INJURY
SLIGHT DAMAGE 20 y
4 - 20 y
0.5 - 4 y
0 - 0.5 y
RCMETBF
> 20 y
4 - 20 y
0.5 - 4 y
0 - 0.5 y NOT acceptable for non age-relateddegradation mechanismsAdditional
processmonitoringNOT required
RRM CRITICALITY MATRIXfor non age-related degradation
STF (RBI): Susceptibility to FailureDR (IPF): Demand RateETBF (RCM): Estimated Time Between Failures
X = Intolerable E = ExtremeH = High M = MediumL = Low N = Negligible
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75 Shell Global SolutionsP-B-v1.1
CONFIDENCE RATING non-age related degradation
Confidence Rating Adjustment factorVH - Very high + 0.2H - High + 0.1M - Medium 0L - Low -0.1VL - Very Low -0.2
Description Score
YES Int. NO
Degradation mechanism can be easily controlled + 0.1 0 - 0.1
Relevant proc. parameters are reliably monitored + 0.1 0 - 0.1
Reliable inspections were carried out + 0.1 0 0
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76 Shell Global SolutionsP-B-v1.1
MONITORING AND INSPECTION PLANfor non age-related degradationsMONITORING AND INSPECTION PLANfor non age-related degradations
CONFIDENCE RATINGCRITICALITY VERY LOW LOW MEDIUM HIGH VERY HIGH
NO INSPECTION/PROCESS MONITORING REQUIRED
IMPROVE MONITORING
MONITORING AND OPPORTUNITY INSPECTION
DESIGN AND/OR PROCESS CHANGE REQUIRED
INTOLERABLE
EXTREME
HIGH
MEDIUM
LOWNEGLIGIBLE
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77 Shell Global SolutionsP-B-v1.1
PROCESS MONITORINGnon-age related degradations
Parameters to be monitored, as described in the operating window.
Frequency to be described/agreed.
Deviations measured (outside monitoring scheme) shall be discussed in the team and actions reported;changes via Plant Change procedure if needed.
Revise inspection plans if needed.
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78 Shell Global SolutionsP-B-v1.1
INSPECTION/MONITORING TIMING?
AGE-RELATED DEGRADATIONS - INSPECTIONS
Calculate Remnant Life Apply Interval Factor: Max. inspection interval
based on Confidence and Criticality Rating
NON AGE-RELATED DEGRADATIONS - MONITORING
Apply table to check if monitoring is required/acceptable: monitoring scheme (+ opportunity inspections)
Based on Confidence and Criticality Rating
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79 Shell Global SolutionsP-B-v1.1
CRITICALITYMATRIX
negligiblecriticality
intolerablecriticality
LOW/MEDIUM/HIGH& EXTREME CRITICALITY
no inspection rectify
INSPECTION/MONITORING TASKS
INFORMATION FROMDEGRADATIONMODULES OR
NDT HANDBOOK
CONFIDENCE RATING
NON-AGE RELATED DEGRADATIONS
INSPECTION INTERVAL
NON-INTRUSIVE/INTRUSIVE
PROCESS MONITORINGAND OPPORTUNITY INSPECTION
REMNANT LIFE
CONFIDENCE RATING
AGE RELATED DEGRADATIONS
RECTIFY IFREQUIRED
INSPECTION TASKS
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80 Shell Global SolutionsP-B-v1.1
Shell Global Solutions
BACK-UPSLIDES
-
81 Shell Global SolutionsP-B-v1.1
NDT TECHNIQUES - see NDT Handbook INTERNAL WALL THINNING internal corrosion UT, RT, MFL, LRUT, PET erosion UT, RT, MFL, LRUT, PET cavitation UT, RT, MFL, LRUT, PET weld corrosion UT, RT
EXTERNAL WALL THINNING external corrosion VT corrosion under insulation VT,RT,TT,RTR, PET
CRACKING fatigue UT, PT, MT, ET, TOFD, AET stress corrosion cracking UT, PT, MT, ET, TOFD, AET wet hydrogen cracking UT, PT, MT, ET, TOFD, AET
OTHER creep DM, R, PT, MT, UT hot hydrogen damage MT, R, UT high temperature embrittlement MT, R, UT
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82 Shell Global SolutionsP-B-v1.1
FEEDBACK/REVIEW VALIDATION AND UPDATING
OF THE PLANT INTEGRITY DATABASE: after each maintenance and inspection shutdown at the implementation of plantchanges at deviations of operating conditions
YEARLY REVIEW BY RBI-TEAM TO ESTABLISH: actual condition and fitness for purpose degradation mechanism and -rate confidence rating
UPDATE INSPECTION PLAN, IF REQUIRED
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83 Shell Global SolutionsP-B-v1.1
RBI METHODOLOGY REVIEW THE OPERATING CONDITIONS OF THE PLANT past/present/future operating conditions process monitoring main changes from design
REVIEW MATERIALS OF CONSTRUCTION check materials vs process conditions
DEFINE CORROSION LOOPS similar process conditions/materials/degradations
DO THE S-RBI STUDY FOR EACH CORROSION LOOP (following slide)
INTEGRATE RESULTS IN AN OVERALL WORK-PLANNING
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84 Shell Global SolutionsP-B-v1.1
S-RBI STUDY FOR A CORROSION LOOP Define the Corrosion Loop Describe process conditions Establish the Operating Window List Items in the loop materials and corrosion allowances (design)
Agree Potential Degradation Mechanisms for the loop Review inspection history - corrosion rates Give a Confidence Rating for each item and degradation Do the criticality rating per Degradation Mechanism Establish remnant life & max. inspection interval OR
monitoring scheme Define scope of inspections / monitoring
next stage - DEVELOP DETAILED INSPECTION PLANS
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85 Shell Global SolutionsP-B-v1.1
DEGRADATION MECHANISMS
Internal corrosion (general) Sulphur, TAN, Acids, H2S
External corrosion CUI, ESCC
Creep Stress Corrosion Cracking Embrittlement Fatigue - thermal Fatigue - mechanical Erosion Hydrogen attack
AGE - RELATED DEGRADATIONS
NON AGE - RELATED DEGRADATIONS
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86 Shell Global SolutionsP-B-v1.1
AGE-RELATED DEGRADATIONS VSNON AGE-RELATED DEGRADATIONS (1)
AGE-RELATED
D
e
g
r
a
d
a
t
i
o
n
Time
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87 Shell Global SolutionsP-B-v1.1
AGE-RELATED DEGRADATIONS VSNON AGE-RELATED DEGRADATIONS (2)
AGE-RELATED
NON AGE-RELATEDE.G. SCC
D
e
g
r
a
d
a
t
i
o
n
Time
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88 Shell Global SolutionsP-B-v1.1
A
C
B
CAUSTIC SODA SERVICE DIAGRAM
Concentration NaOH, % weight
T
e
m
p
e
r
a
t
u
r
e
(
C
)
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89 Shell Global SolutionsP-B-v1.1
Table S1-2A Environmental Severity - SSC H2S CONTENT OF WATER (mg/kg)
pH of water Cyanide content (mg/kg)
< 50 50 to 1000 > 1000
SEVERITY CATEGORY
< 4.0 (Note 1) Moderate High High
4.0 to 5.4 (Note 1) Low Moderate High
5.5 to 7.5 (Note 1) Low Low Moderate
7.6 to 7.9 < 50 Low Moderate High
7.6 to 7.9 50 Moderate High High 8.0 < 20 Low Moderate High 8.0 20 Moderate High High
NOTE 1. HCN level is not significant at pH 7.5 and below.
SUSCEPTIBILITY TO FAILURE BY SSC
Table S1-3 Susceptibility to SSCAs-welded PWHT
Environmental Max Vickers Hardness(1) Max Vickers Hardness(1)
Severity < 248 248-290 > 290 < 248 248-290 > 290
High Low Medium High Not Low Medium
Moderate Low Medium High Not Not Low
Low Low Low Medium Not Not Not(1) Actually tested as Vickers or converted from portable techniques, e.g. Equotip, Microdur etc.
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90 Shell Global SolutionsP-B-v1.1
FATIGUE MONITORING (PROPOSAL)monitoring/inspection interval(s) FATIGUE MONITORING (PROPOSAL)monitoring/inspection interval(s)
NO INSPECTIONS
CONFIDENCE RATINGVERY LOW LOW MEDIUM HIGH VERY HIGHCRITICALITY
EXTREME
HIGH
MEDIUM
LOW
1 DAY 3 DAYS
1 WEEK 1 MONTH
2 MONTHS
NEGLIGIBLE
INTOLERABLE SEE NOTE
NOTE:Where Fatigue could lead to X = INTOLERABLE criticality,a full supporting system shall be designed and maintained;for criticality E, a similar approach is usually followed.
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91 Shell Global SolutionsP-B-v1.1
RRM CRITICALITY MATRIX
N LL MM
E
H
XEH
HMM
MMLL
LL
N
N
XXEHLL3
2
1
4
P
R
O
B
A
B
I
L
I
T
Y
C
L
A
S
S
MULTIPLEFATALITIES
EXT. DAMAGE>10M
SLIGHT INJURY
SLIGHT DAMAGE 20 y
4 - 20 y
0.5 - 4 y
0 - 0.5 y
RCMETBF
> 20 y
4 - 20 y
0.5 - 4 y
0 - 0.5 y
STF (RBI): Susceptibility to FailureDR (IPF): Demand RateETBF (RCM): Estimated Time Between Failures
X = Intolerable E = ExtremeH = High M = MediumL = Low N = Negligible
-
92 Shell Global SolutionsP-B-v1.1
0.10
1.00
10.00
100.00
1,000.00
1 10 100 1000
Vibration Frequency, Hz
V
i
b
r
a
t
i
o
n
A
m
p
l
i
t
u
d
e
,
m
i
l
s
p
e
a
k
t
o
p
e
a
k
Danger
Correction
Marginal
Design
Threshold of perception
SEVERITY OF VIBRATIONZONE 1
ZONE 4
23
ALLOWABLE PIPING VIBRATION LEVELS
-
93 Shell Global SolutionsP-B-v1.1
S-RBI AS PART OF RRMmain changes
CONSEQUENCE OF FAILURE new questionnaire, identical for S-RBI, S-RCM and IPF
SUSCEPTIBILITY TO FAILURE new questionnaire
AGE AND NON-AGE RELATED DEGRADATIONS different approach
TECHNICAL MODULES give guidance to StF ratings
CONFIDENCE RATING INTERVAL FACTORS
-
94 Shell Global SolutionsP-B-v1.1
StF - CORROSION RATESdesign life 20 years
CA 1mm CA 3mm
CR CR
4 H >0.2 >0.6
3 M >0.05 - 0.2 >0.15 - 0.6
2 L 0.02 - 0.05 0.07 - 0.15
1 N
-
95 Shell Global SolutionsP-B-v1.1
CORROSION ALLOWANCESspecial cases
STAINLESS STEEL AND ALLOYS no corrosion allowance in designs
use tolerances, +/12.5% (FFP can give actual value) or take an arbitrary small value, e.g. 0.5 mm also take a worst case CR, e.g. 0.01 mm/yr that results in 50 years initial lifetime
HEAT EXCHANGER TUBES wall thickness is CA 50% for inside, 50% for outside, if leaks are accepted sometimes users want e.g. 0.5 mm minimum for pressure
containment. higher minimum thickness can be agreed.
-
96 Shell Global SolutionsP-B-v1.1
HEAT EXCHANGER DEFINITIONS
Shell side Tube side
Shell (Sh)
Tube outside (To)
Head (He)
Tubeinside(Ti)
-
97 Shell Global SolutionsP-B-v1.1
SUB TAGS & TAG GROUPS
SUB - TAGS
C-20124P10023117X
4 P1005 3117Y
WET PIPINGtags P1002, P1003
16 P1004 3117YC-201 TOP
DRY OH PIPINGTags P1004, P1005, P1006
TAG GROUPSC-201 Bottom
12 P1003 3117X
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98 Shell Global SolutionsP-B-v1.1
FAILURE
TERMINATION OF THE ABILITY OFAN ITEM TO PERFORM A REQUIRED FUNCTION: corrosion allowance lost (after FFP) below minimum required thickness leak to outside (or internal) crack detected (beyond tolerable) deformation (beyond tolerable) extreme case: rupture
brittle or ductile
NORMAL DESIGNS - LEAK BEFORE BREAK: warns and allows to avoid hazards
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99 Shell Global SolutionsP-B-v1.1
PLANTSrisk and reliability - mechanical
PLANT DEGRADATIONS INSPECTION MAINTENANCE
visualultrasonicX-rayinfraredmagnetic part.dye penetranteddy current
pHtemperaturechloride level
corrosion- general- pitting- Stress CCmechanical- fracture- fatigue- etc.
repairreplace
preventiveorbreak down
timing ofinspection/monitoring tasks
processconditions
+
DESIGNPER CODEpressure/
temperature
materials
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100 Shell Global SolutionsP-B-v1.1
FAILURE CLASSIFICATION
CORROSION STRESS
SURFACE GRANULARINTER/TRANS
LOCALISEDCORROSION
GENERALCORROSION
NON-FLUCTUATING FLUCTUATING
OVERLOAD TEMPERATUREEFFECTS
BRITTLEFRACTURE
LOW HIGH
CREEPRUPTURE
THERMALFATIGUE
DUCTILEFRACTURE
THERMAL
MECHANICAL
HYDRAULIC
CAVITATIONerosion
FATIGUEWEAR
CORROSIONFATIGUE
STRESSCORROSIONCRACKING
HYDROGENEMBRITTLEMENT
OGBR MHR
- pitting- crevice- galvanic- fretting- velocity
(erosion)
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101 Shell Global SolutionsP-B-v1.1
S-RBI RELATED TOOLS
Maintenanceand Inspection
Database
Electronic Drawings(VISIO)
TrendingSoftware
S-RBI ANALYSIS
S-RBI (RRM)Software
S-RBI (RRM)Manual
MEP/Corrosion ControlManual
Statistical Recipe Book
DegradationLibrary
NDTHandbook
FFPHandbook
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102 Shell Global SolutionsP-B-v1.1
S-RBI IN COMPARISON WITH API STANDARDS (1) API 510 Pressure Vessel Inspection codeAPI 570 Piping Inspection codeAPI RP 580 Risk Based Inspection DRAFT
S-RBI FULLY IN LINE WITH API REQUIREMENTS
involve various part of organisation incorporate likelihood and consequence of failure include HSE consequences assess all potential degradation mechanisms evaluate effectiveness of inspection methods re-assessment after process change consider design relative to operating conditions RBI assessment should be properly documented
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103 Shell Global SolutionsP-B-v1.1
S-RBI IN COMPARISON WITH API STANDARDS (2)ADDITIONAL ADVANTAGES OF S-RBI team effort is pre-requisite approach is very practical, easy to apply and transparent auditable consideration to assure integrity and define inspection plan corrosion loop concept streamlines the analysis and adds clarity linked to Corrosion Control Manual definition of (integrity) operating window comprehensive but concise report enhanced synergy of S-RBI with S-RCM and IPF under RRM S-RBI based on long lasting experience and applied within Shell
worldwide
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104 Shell Global SolutionsP-B-v1.1
WALL THICKNESS UT MEASUREMENTS
POOR QUALITY+/ 1 mm
GOOD QUALITY+/ 0.5 mm
109 11
High quality UT measurements canobtain +/ 0.3 mm
109 11
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105 Shell Global SolutionsP-B-v1.1
DEFECT SIZES UPON FAILURE Standard hole size 3 mm for gas and 3 - 5 mm for liquids for
normal degradations leading to pitting and small holes; these sizes are detected rather quickly and precautions
will be in hand if sizes are larger: depressurization evacuation firefighting etc.
A 1 inch hole for degradations leading to large area thinning, e.g. ammonium chloride salt attack.
Ruptures are considered if embrittlement is encountered or large scale Stress Corrosion Cracking could occur.
Local standards/philosophies can overrule these sizes.
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106 Shell Global SolutionsP-B-v1.1
TAG NUMBERS
ADVISED DETAILS:
PIPING (max 25 characters) size line code 8 PL1010 CS HI INSP material insulation code authority code (if applicable)
EQUIPMENT TAG number insulation code V-1101 CI INSP authority code E-302 TS Ti HI INSP
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107 Shell Global SolutionsP-B-v1.1
STANDARDIZED CORROSION RATES (CR)CARBON STEEL If no corrosion detected after about 10 years: Assume detection limit of 0.5 mm, corrosion rate must be lower
than 0.05 mm/yr Use this value as worst case CR until better information is
available
STAINLESS STEEL If no corrosion detected after about 10 years Assume detection limit of 0.1 mm, corrosion rate must be lower
than 0.01 mm/yr (after VT) or 0.03 mm/yr (if UT, good quality) Use this value as worst case CR until better information is
available
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108 Shell Global SolutionsP-B-v1.1
STRESS CORROSION CRACKING
START
Is the material ofconstruction austenitic
stainless steel?
Determine theseverity index for
each potentialmechanism
Have youdetected SCC in this
or similar serviceequipment?
Do you know thecause of SCC?
Increase thesusceptibility for
that mechanism tohigh
Increase susceptibilityfor all potential
mechanisms to high
No problem
No
Determine maximumseverity index
Is the material ofconstruction carbon or
low alloy steel?
Yes
No
NoYesYes Yes
Screen for Caustic, Amine,SSC, HIC/SOHIC,
Carbonate Cracking
Screen for PTA,Cl-SCC
No
Determine susceptibility foreach potential SCC
mechanism for austeniticStainless Steels
Determine susceptibilityfor each potential SCC
mechanism for Carbon andLow Alloy steels
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109 Shell Global SolutionsP-B-v1.1
MAXIMUM INSPECTION INTERVAL
X
MIN. ALLOWABLE THICKNESSt(min)
t new
LIFETIME IN YEARS
Inspections
X
NLMH
20
40
< 5 ~ 5 -10
N to H CriticalityVL to VH Confidence0.1 - 0.8 Int. Factor
L to E (X) CriticalityVL to VH Confidence0.0 - 0.7 Int. Factor
StF
t
h
i
c
k
n
e
s
s
design life
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110 Shell Global SolutionsP-B-v1.1
EFFECT OF MONITORING/INSPECTION AND/OR MITIGATIONEFFECT OF MONITORING/INSPECTION AND/OR MITIGATION
REMAINING RISK = CRITICALITY - PREVENTIVE MEASURES
P
r
o
b
a
b
i
l
i
t
y
LOW RISK
HIGH RISK
Criticality
monitoring/inspectioneffect
Define inspection tasksto get lowest possible riskConsequence
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111 Shell Global SolutionsP-B-v1.1
REMAINING RISK TO BEAS LOW AS REASONABLY POSSIBLE (ALARP)
P
r
o
b
a
b
i
l
i
t
y
LOW RISK
Criticality
HIGH RISK
(ALARP)
1. Inspection interval and coverage- based on Criticality andConfidence Rating
2. Type of Inspection(s)- based on failure mode(s)
3. Location(s) to inspect- for each failure mode
4. Process Monitoring- where applicable (operating window)
Consequence
-
112 Shell Global SolutionsP-B-v1.1
FAILURE MODE & CONSEQUENCES
Consequence of Failureworst case & if flammable contents
Typical defect:w
Degradationw
Failure modew
Pitting Small leak Leak, no significant damage Hole, 3-5 mm dia Small fire System Inventory(Big fire or explosion)
Embrittlement Fracture Big fire or explosion System Inventory
Caustic cracking Cracks Leaks Hole, 3-5 mm dia SCC
General corrosion Leak Fire, small explosion Hole, 3-5 mm dia Rupture Big fire or explosion System Inventory
To avoid long discussions, general worst case failure modes are taken as default starting point(modified if required, after discussions)
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113 Shell Global SolutionsP-B-v1.1
YEARS TO MEASURE CORROSION
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
0
.
0
2
0
.
0
4
0
.
0
6
0
.
0
8
0
.
1
0
0
.
1
2
0
.
1
4
Corrosion Rate, mm/yr
M
e
a
s
u
r
e
m
e
n
t
T
o
l
e
r
a
n
c
e
+
/
,
m
m
?
20 years
10 years
3 years
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114 Shell Global SolutionsP-B-v1.1
COST REDUCTIONS
By risk reduction By longer inspection intervals By lower inspection cost
N LL MM
E
H
X
EH
HMM
MMLL
LL
N
N
XXEHLL
3
2
1
4
P
R
O
B
A
B
I
L
I
T
Y
C
L
A
S
S
MULTIPLEFATALITIES
EXTENSIVEDAMAGE >10M
SLIGHT INJURY
SLIGHT DAMAGE
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115 Shell Global SolutionsP-B-v1.1
FAILURE MODEWall thinning- minor loss, < 0.2 x wt- medium loss, < 0.5 x wt- serious loss, > 0.5 x wt- general or localised
Hole- small hole, < 5 mm dia- large hole, > 5 mm dia- very large hole, > 25 mm dia
Cracking- small crack, < 5 mm- medium size crack, < 25 mm- large crack, > 25 mm- through-the-wall
Rupture
DEGRADATION MECHANISM- General corrosion
- Erosion
- Hot H2-attack
- Pitting corrosion
- Fatigue
- Creep
- Stress Corrosion Cracking
- Embrittlement
DEGRADATIONS AND FAILURE MODES
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116 Shell Global SolutionsP-B-v1.1
PROBABILITY OF FINDING LOCALIZED CORROSIONvia Spot Thickness measurements - with replacementPROBABILITY OF FINDING LOCALIZED CORROSIONvia Spot Thickness measurements - with replacement
4020 60 80 1000
5
10
15
N
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o
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a
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g
s
Probability of finding localized corrosion (%)
1% area
2%
5%
10%
25%
50%
75%
90%
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117 Shell Global SolutionsP-B-v1.1
0
40
80
120
160
0.00 0.10 0.20
Proportion corroded
General corrosion on surface area200
50 809095 98% Confidence
S
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STATISTICAL SAMPLING
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118 Shell Global SolutionsP-B-v1.1
PIPING REJECTION THICKNESSES (1)
Piping classes have 1 or 3 mm Corrosion Allowance (CA): 11010 has 1 mm CA for 150 lbs conditions 11030 has 3 mm CA for 150 lbs conditions
Pressures and temperatures are often significantly below the design conditions of the piping classes.
Therefore EXTRA CA is often available. Determine the minimum required wall thickness by: spreadsheet table minimum thickness for mechanical stability
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119 Shell Global SolutionsP-B-v1.1
PIPING REJECTION THICKNESSES (2)
corrosion
- Available schedule/thickness- CA, Corrosion Allowance- Plate/Pipe tolerance- DT, Design Thickness
- TminMinimum Allowable Thickness
- Tminfor single pit
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120 Shell Global SolutionsP-B-v1.1
PIPING REJECTION THICKNESSES (3)PIPING REJECTION THICKNESSES (3)
corrosion wall thickness reduction
Residual wall thickness
Residual Corrosion Allowance
Fitness for Purpose (FFP) extra CAstudy
TminDESIGN
Localized pitting (FFP or Code)
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121 Shell Global SolutionsP-B-v1.1
HEAT EXCHANGER TUBE - CA ?
Internal (tube side) corrosion ?
External (shell side) corrosion ?
Corrosion Allowance CA ? External corrosion
CA = wt ?50/50 Int./Ext.
WT
Internal corrosion
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122 Shell Global SolutionsP-B-v1.1
MINIMUM REQUIRED WALL THICKNESSmax. 250CPipe size
1) B31.3 calculation, CS A106 Bor API 5L-B
2) Max. pipe span as per memo (check), filled with water and weight in the middle
3) Full vacuum4) NOT valid where additional stresses from
expansion etc. occur
DN 25 DN50 DN80 DN100 DN150 DN200 DN250 DN300 DN350
5 barg
10
15 2mm
20 4mm
25 4mm 4mm 5mm
30 3mm 4mm 5mm 5mm
40 4mm 5mm 6mm 7mm
50 4mm 5mm 6mm 8mm 9mm
60 5mm 6mm 8mm 9mm 10mm
75 4mm 6mm 8mm 9mm 11mm 12mm
100 4mm 5mm 8mm 10mm 12mm 14mm 16mm
125 4mm 5mm 7mm 9mm 12mm 15mm 18mm 20mm
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123 Shell Global SolutionsP-B-v1.1
NDT MEASUREMENTS - PLUGS
plug
S-RBI: SHELL RISK-BASED INSPECTIONS-RBI AS PART OF RISK ANDRELIABILITY MANAGEMENT (RRM)S-RBI PROCESSTHE ADVANTAGES OF SINGLE RRM DATABASE FOR RBI/RCM/IPF ANALYSESRBI STUDIES - RRM DATABASERBI STUDY - TEAM SESSIONSCORROSION LOOPSS-RBI IS BASED ON CORROSION LOOPSCORROSION LOOPS FOR A KERO HDTEXPERIENCE WITH CORROSION LOOPSCRITICALITY ASSESSMENTSUSCEPTIBILITY TO FAILUREINSTEAD OF PROBABILITYCRITICALITY RATINGSUSCEPTIBILITY TO FAILURE (STF) (1)SUSCEPTIBILITY TO FAILURE INTERNAL CORROSIONgeneral & localized corrosionStF - NON AGE-RELATED DEGRADATIONS (1)CAUSTIC CRACKING MODULEAPI 581 and degradation libraryStF - NON AGE-RELATED DEGRADATIONS (2)StF - NON AGE-RELATED DEGRADATIONS (3)StF - DEGRADATION MODULESfor further informationCONSEQUENCE OF FAILURE ASSESSMENTECONOMICSDIRECT ASSESSMENT OFECONOMIC CONSEQUENCESECONOMIC CONSEQUENCESsimple questionnairePRODUCTION LOSS EQUATIONSTAGGERED PRODUCTION LOSS EQUITIONHEALTH AND SAFETYHSE RAM DEFINITIONSHEALTH & SAFETYsimple questionnaire (1)HEALTH & SAFETYdetailed questionnaireHEALTH AND SAFETYfireFIREdetailed H & S questionnaireRELEASE OF LIQUID THROUGH A HOLEHEALTH AND SAFETYexplosionsEXPLOSIONdetailed H & S questionnaireRELEASE OF GASthrough a 3 mm hole C1-C2 and H2RELEASE OF LPG THROUGH A 3 MM HOLEEXPLOSION & HPdetailed H & S questionnaireHIGH PRESSURE CONSEQUENCE OF GAS PIPESHEALTH AND SAFETYtoxic effectsTOXIC RELEASESdetailed H & S questionnaireHEALTH AND SAFETYmitigationMITIGATIONdetailed H & S questionnaireENVIRONMENTENVIRONMENTALsimple questionnaireENVIRONMENTALdetailed questionnaireENVIRONMENTALdetailed questionnaireDETERMINATION OF THECONSEQUENCE OF FAILURE - SummaryCONFIDENCE RATINGPROCESS MONITORINGnon-age related degradationsINSPECTION/MONITORING TIMING?INSPECTION TASKSRBI METHODOLOGYS-RBI STUDY FOR A CORROSION LOOPDEGRADATION MECHANISMSAGE-RELATED DEGRADATIONS VSNON AGE-RELATED DEGRADATIONS (1)AGE-RELATED DEGRADATIONS VSNON AGE-RELATED DEGRADATIONS (2)ALLOWABLE PIPING VIBRATION LEVELSS-RBI AS PART OF RRMmain changesStF - CORROSION RATESdesign life 20 yearsCORROSION ALLOWANCESspecial casesHEAT EXCHANGER DEFINITIONSSUB TAGS & TAG GROUPSFAILUREPLANTSrisk and reliability - mechanicalS-RBI IN COMPARISON WITH API STANDARDS (1) API 510Pressure Vessel Inspection codeAPI 570PipiDEFECT SIZES UPON FAILURETAG NUMBERSSTANDARDIZED CORROSION RATES (CR)DEGRADATIONS AND FAILURE MODESPIPING REJECTION THICKNESSES (1)PIPING REJECTION THICKNESSES (2)HEAT EXCHANGER TUBE - CA ?NDT MEASUREMENTS - PLUGS