Shell RBI Methodology
December 28, 2016 | Author: Abdullah Dinsuhaimi | Category: N/A
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Shell Global Solutions
S-RBI
SHELL RISK-BASED INSPECTION - THE METHODOLOGY Risk and Reliability Management Presenter: Maarten Festen BUSINESS GROUP MAINTENANCE, INSPECTION AND RELIABILITY ENGINEERING P-B-v1.1
© Shell Global Solutions
1
S-RBI: SHELL RISK-BASED INSPECTION •
S-RBI Work flow ¾
•
S-RBI methodology ¾
P-B-v1.1
in the RRM software part of RRM Manual, issued in 1999
© Shell Global Solutions
2
S-RBI AS PART OF RISK AND RELIABILITY MANAGEMENT (RRM) RRM
S-RBI
methodology and database
S-RCM
IPF
SHELL Reliability R Centered Maintenance
Instrumented Protective Functions (safeguarding systems)
P-B-v1.1
© Shell Global Solutions
3
S-RBI PROCESS ASSET INTEGRITY DATABASE
S-RBI PACKAGE
CORROSION LOOP DESCRIPTIONS CRITICALITY ASSESSMENT CONFIDENCE ASSESSMENT
ANALYSIS/REVIEW FEEDBACK
TASK EXECUTION
INSPECTION/MONITORING PLANNING
P-B-v1.1
© Shell Global Solutions
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THE ADVANTAGES OF SINGLE RRM DATABASE FOR RBI/RCM/IPF ANALYSES •
•
•
COMMON USE OF RESOURCE DATA ¾
pick lists for e.g. equipment types, materials etc.
¾
Consequence of Failure analysis/data
STANDARD CRITICALITY DEFINITION ¾
1 Criticality Matrix
¾
in line with HSE standard (RAM, April 1999)
TASKS FOR EACH ITEM DEFINED ON SAME CRITERIA ¾
P-B-v1.1
tasks can be compared & optimised © Shell Global Solutions
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RBI STUDIES - RRM DATABASE PREPARATION, WHERE POSSIBLE BEFORE THE STUDIES: •
Common part can be filled ¾
•
Assets can be filled ¾
•
or used from S-RCM or IPF, if already carried out
Inspection information can be entered ¾
P-B-v1.1
or used from S-RCM or IPF, if already carried out
“one liners”, giving relevant information only
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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 ¾
P-B-v1.1
mainly by inspection & corrosion members, team review
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Shell Global Solutions
S-RBI METHODOLOGY
P-B-v1.1
© Shell Global Solutions
8
SIMPLIFIED S-RBI FLOW CHART (1) Asset Integrity Database Review operating conditions and Materials Selection
Analysis & Feedback Corrosion Loops
1
Equipment Item
Loop Criticality Assessment Loop Criticality Negligible
Item Criticality NO
Negligible
YES
No inspection Review only RCM P-B-v1.1
RECTIFY
Inspection / Monitoring
Low
Medium
INTOLERABLE
High
Extreme
Inspection/ Monitoring Interval & Scope © Shell Global Solutions
9
CORROSION LOOPS DIVIDE THE UNIT IN CORROSION LOOPS
P-B-v1.1
•
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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S-RBI IS BASED ON CORROSION LOOPS CORROSION
WHAT TYPE OF DEGRADATION CAN OCCUR AND WHERE ? MATERIAL + ENVIRONMENT WHICH (PROCESS) CONTROLS ARE NEEDED ?
P-B-v1.1
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WHAT IS A “CORROSION LOOP”? “A PRACTICAL WAY TO DESCRIBE, UNDERSTAND AND CHECK DEGRADATION MECHANISMS IN A UNIT”
•
P-B-v1.1
PART OF THE UNIT SUBJECTED TO: ¾ the same process conditions ¾ the same failure mechanisms ¾ the same materials selection criteria ONE “OPERATING WINDOW” ¾ control of degradations via process control ¾ values agreed by team (boundary conditions for RBI) ¾ deviation should be reported
CORROSION LOOP 12-E-102
Loop 2 12-E-101 Loop 1
12-D-101
•
Loop 3 12-K-101
1st stage
12-G-101
to burn pit
• same process conditions • same degradation mechanisms © Shell Global Solutions
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CORROSION LOOPS FOR A KERO HDT Hydrogen from Platformer
Feed from CDU
Recycle Hydrogen E-1202 R-1201 CTW
5Cr 0.5Mo
CS E-1201
1.25Cr 0.5Mo
cs cs cs as as ss F
E
To Fuel Gas system
D
C
B
321 SS
A Product to Stripper
CS
Sour Water
P-B-v1.1
© Shell Global Solutions
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EXPERIENCE WITH CORROSION LOOPS
P-B-v1.1
•
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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CRITICALITY ASSESSMENT FOR THE CORROSION LOOP: • Stop if Negligible Criticality or Negligible Consequence of Failure is obtained (no further analysis on item by item basis) ¾ 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 ¾ can be grouped for similar piping items into e.g. “LP piping” ¾ can be divided into 2 loops, e.g. “Column top”, and “Column bottom”
P-B-v1.1
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SIMPLIFIED S-RBI FLOW CHART (2) Asset Integrity Database Review operating conditions and Materials Selection
Analysis & Feedback
1
Corrosion Loops Loop Criticality Assessment Loop Criticality Negligible
2
P-B-v1.1
RECTIFY
Item Criticality NO
Negligible
YES
No inspection Review only RCM
Equipment Item
Inspection / Monitoring
Low
Medium
INTOLERABLE
High
Extreme
Inspection/ Monitoring Interval & Scope © Shell Global Solutions
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PROBABILITY
CRITICALITY MATRIX HIGH MEDIUM LOW NEGLIGIBLE S-RBI
NEGLIGIBLE NO INSPECTION REVIEW ONLY
P-B-v1.1
L L
H M
E H
X E
X X
N N
L N
M L
H M
E H
NEGLI LOW GIBLE
MED IUM
HIGH EXTEN SIVE
CONSEQUENCES
LOW
MEDIUM
INTOLERABLE RECTIFY
EXTREME CRITICALITY DETAILED ANALYSIS
HIGH CRITICALITY
INSPECTION PLAN
© Shell Global Solutions
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SUSCEPTIBILITY TO FAILURE INSTEAD 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
P-B-v1.1
© Shell Global Solutions
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CRITICALITY RATING •
Determine the Susceptibility to Failure (StF)
•
Determine the Consequence of Failure (CoF)
•
Combination of StF and CoF yields the Criticality
Ö CRITICALITY = potential risk without preventive measures or corrections
P-B-v1.1
© Shell Global Solutions
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RBI CRITICALITY MATRIX (1) RRM CRITICALITY CLASS
4
HIGH
L
H
E
X
X
3
MEDIUM
L
M
H
E
X
2
LOW
N
L
M
H
E
1
NEGLIGIBLE
N
N
L
M
H
CONSEQUENCE CATEGORY
PROBABILITY CLASS
SUSCEPTIBILITY TO FAILURE
ECONOMICS (USD)
SLIGHT DAMAGE MINOR DAMAGE LOCAL DAMAGE MAJOR DAMAGE EXTENSIVE 10M
HEALTH & SAFETY
SLIGHT INJURY
MINOR INJURY
ENVIRONMENT
SLIGHT EFFECT
MINOR EFFECT
LOCAL EFFECT
MAJOR EFFECT
NEGLIGIBLE 1
LOW 2
MEDIUM 3
HIGH 4
CONSEQUENCE CLASS
MAJOR INJURY SINGLE FATALITY
MULTIPLE FATALITIES MASSIVE EFFECT EXTREME 5
X = Intolerable E = Extreme H = High M = Medium L = Low N = Negligible P-B-v1.1
© Shell Global Solutions
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RBI CRITICALITY MATRIX (2) RRM CRITICALITY CLASS
4
HIGH
L
H
E
X
X
3
MEDIUM
L
M
H
E
X
2
LOW
N
L
M
H
E
1
NEGLIGIBLE
N
N
L
M
H
CONSEQUENCE CATEGORY
PROBABILITY CLASS
SUSCEPTIBILITY TO FAILURE
ECONOMICS (USD)
SLIGHT DAMAGE MINOR DAMAGE LOCAL DAMAGE MAJOR DAMAGE EXTENSIVE 10M
HEALTH & SAFETY
SLIGHT INJURY
MINOR INJURY
ENVIRONMENT
SLIGHT EFFECT
MINOR EFFECT
CONSEQUENCE CLASS
MAJOR INJURY SINGLE FATALITY
NORMAL DESIGN CASE LOCAL EFFECT
MAJOR EFFECT
3
HIGH 4
NEGLIGIBLE OR LOW NEGLIGIBLE SUSCEPTIBILITY LOW MEDIUM TO FAILURE 1
2
MULTIPLE FATALITIES MASSIVE EFFECT EXTREME 5
NOTE: Medium or High StF can occur e.g. as a result of changed operating conditions P-B-v1.1
© Shell Global Solutions
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Shell Global Solutions
SUSCEPTIBILITY TO FAILURE ASSESSMENT
P-B-v1.1
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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. ¾
•
P-B-v1.1
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. ¾
Different inspection techniques/intervals may be required.
¾
Monitoring scheme to be indicated for non-age realated degradations.
© Shell Global Solutions
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SUSCEPTIBILITY TO FAILURE (STF) (2) •
The failure mode will influence the Consequence of Failure and therefore the Criticality. ¾
P-B-v1.1
The “item criticality” will be the highest rating of all failure modes.
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SUSCEPTIBILITY TO FAILURE (STF) (3)
P-B-v1.1
•
AGE RELATED DEGRADATIONS ¾ time factor (very) important in relation to degradation ¾ degradations can be foreseen/predicted and controlled – general corrosion (thinning) – creep ¾ part of normal design criteria, basis for “design life”
•
NON-AGE RELATED DEGRADATIONS ¾ time factor not important in relation to degradation ¾ 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 © Shell Global Solutions
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FAILURE MODES
Time 5
PoF
2
Time Tim e
PoF
6
SCC due to a Process upset ?
Time
More failures occur shortly after installation, repair or overhaul
Time Tim
Time
⇒ ⇒ P-B-v1.1
PoF
Time 3
Random failures
PoF
Time
Failures are mostly random with only a few early-life failures PoF
4
PoF
1
NON-AGE-RELATED PoF
AGE-RELATED
internal/external corrosion creep © Shell Global Solutions
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SUSCEPTIBILITY OF FAILURE determine failure characteristic failure characteristic: non age-related
failure characteristic: age-related DEGRADATION MODULES THINNING
determine susceptibility based on the ratio: actual corrosion rate/ design corrosion rate
P-B-v1.1
- CRACKING - H-ATTACK - MECHANICAL
CREEP
determine susceptibility based on the operating conditions
determine Susceptibility based on API Technical Modules Fitness for Service study
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StF - AGE-RELATED DEGRADATIONS 1 Internal Corrosion
The actual corrosion rate is very high
(e.g. > 4 × CRd)
H
(e.g. 1 - 4 × CRd)
M
General and/or localised The actual corrosion rate is high
The actual corrosion rate is acceptable/low (e.g. 0.5 - 1.0 × CRd) The actual corrosion rate is very low 2 External Corrosion Corrosion under insulation
(e.g. < 0.5 × CRd)
L N
Severe external corrosion ( e.g. 60 -120 °C with high humidity and/or spray, condense, cycling conditions, damaged insulation)
H
Serious external corrosion , (e.g. -5 to 60 °C or 120 - 150 °C and humid climate, damaged insulation)
M
Minor external corrosion under normal operating conditions(0.05mm/yr) L
3 Creep
P-B-v1.1
No foreseeable external corrosion (not insulated or >150 °C)
N
Operation in the creep range, risk of major upsets which must be quantified in terms of remnant life
H
Operation in the creep range, risk of minor upsets which must be quantified 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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SUSCEPTIBILITY TO FAILURE INTERNAL CORROSION
general & localized corrosion Corrosion Rating for Susceptibility to Failure H igh
> 4 x design CR
M edium
>1 - 4 x design CR
L ow
0.5 - 1 x design CR
RRM MATRIX
N egligible < 0.5 x design CR
P-B-v1.1
© Shell Global Solutions
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StF - NON AGE-RELATED DEGRADATIONS (1) 4 Fatigue - Thermal
5 Fatigue - Vibrations
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
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 M zone3 Vibrating in zone 3
L
No foreseeable fatigue due to vibration (zone 4 or no vibrations
N
6 Stress Corrosion Cracking High susceptibility External or internal
P-B-v1.1
H
Medium susceptibility
M
Low susceptibility
L
Not susceptible
N
© Shell Global Solutions
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CAUSTIC CRACKING MODULE API 581 and degradation library
Start Yes
Stress Relieved?
Not Susceptible
No Plot Point on NACE Caustic Soda Service Graph
NaOH Concentration Yes Yes
Heat traced? No
NaOH conc 10 M USD
Substantial or total loss of operation
definitions as given in the HSE RAM P-B-v1.1
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ECONOMIC CONSEQUENCES simple questionnaire ELEMENT
COST
Production loss
1
k
Repair costs
2
k
Labour
3
k
Total
6
k
Economic consequence class: N
P-B-v1.1
© Shell Global Solutions
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PRODUCTION LOSS EQUATION Production losses Down time
6
hr
Reduced throughput
5
hr
Miscellaneous
@
20
%
=
100
kUSD
=
50
kUSD
=
30
kUSD
Total production losses
180
kUSD
Repair costs Materials / Equipment
=
10
kUSD
Fixed contractor costs
=
4
kUSD
Miscellaneous
=
0
kUSD
Total repair costs
14
kUSD
Labour
P-B-v1.1
Craftsmen
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
© Shell Global Solutions
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STAGGERED PRODUCTION LOSS EQUITION 100
Loss [kUSD]
80
PLE example: 0 - 2 h: 2 kUSD/h 2 - 8 h: 4 kUSD/h > 8h : 8 kUSD/h
60
5 periods can be defined
8
40
2
20 0 0
t1
5
t2
10
15
Time [h]
In software 2 and 8 should be entered as the inputs with the loss value up to that limit P-B-v1.1
© Shell Global Solutions
42
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 overall Health and Safety class
•
“Simple” questionnaire connects the degree of hazard to Health and Safety descriptions ¾
P-B-v1.1
e.g. medium fire which could cause minor injuries
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HSE RAM DEFINITIONS Table 3-2 Health/Safety consequence definitions as given in the HSE RAM document
P-B-v1.1
Class
Potential Impact
Description
N
No/Slight injury
First aid case and medical treatment case. Not affecting work performance or causing disability.
L
Minor injury
Lost time injury. Affecting work performance, such as restriction to activities or a need to take a few days to fully recover (maximum one week).
M
Major injury
Including permanent partial disability. Affecting work performance in the longer term, such as prolonged absence from 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 (maximum 3) in close succession due to the incident, e.g. explosion.
E
Multiple fatalities
May include 4 fatalities in close succession due to the incident, or multiple fatalities (4 or more) each at different points and/or with different activities.
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HEALTH & SAFETY simple questionnaire (1) CONSEQUENCE CLASS
CONSEQUENCE DESCRIPTION
FIRE 1 2 3 4
N L M H
Failure mode leads to: No fire or fire which could only cause slight injuries (no LTI) Fire which could cause minor injuries (LTI) Fire which could cause major injuries (LTI> 1 week and/or partial disability) Fire causing up to a single fatality or permanent total disability
EXPLOSION
P-B-v1.1
1 2 3
N L M
4
H
5
E
Failure mode leads to: No explosion but just a flash fire which could only cause slight injuries (first aid) No explosion but a flash fire which could cause minor injuries (LTI) Explosion or flash fire which could cause major injuries (LTI>1week and/or partial disability) Explosion or flash fire which could cause a single fatality or permanent total disability Explosion which could cause multiple fatalities
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HEALTH & SAFETY simple questionnaire (2) CONSEQUENCE CLASS
CONSEQUENCE DESCRIPTION
TOXIC 1 2 3
N L M
4 5
H E
Failure mode leads to: No or very small toxic release which could cause only slight injuries (first aid) Small toxic release which could cause minor injuries (LTI) Medium toxic release which could cause major injuries (LTI>1week and/or partial disability) Large toxic release which could cause a single fatality or permanent total di bilit Very large toxic release which could cause multiple fatalities
MITIGATION
0 -1 -2
P-B-v1.1
Exposure near failure location and possibility to avert danger of hazardous event could reduce possible H/S consequence class by: No means or only marginally One class Two classes
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HEALTH & SAFETY detailed questionnaire Table 3-4 quantity
quantity released
Common consequence matrix 4
N
H
E
E
3
N
M
H
E
2
N
L
M
H
1
N
N
L
M
1
2
3
4
Consequence of Failure Negligible to Extreme
property For fires
P-B-v1.1
flammability
© Shell Global Solutions
47
HEALTH AND SAFETY fire •
Two parameters are used to estimate fire consequence: ¾
Flammability –
¾
Released quantity (instantaneous/per hour/inventory) –
•
P-B-v1.1
NFPA (National Fire Protection Association) flammability index, 0 ≤ Nf ≤ 4 and temperature three levels: < 500 kg, 0.5 - 5 ton, and > 5 ton
Matrix to determine fire class (Max H)
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FIRE detailed H & S questionnaire Nf
P ro d u cts
0
S ulphur D iox ide, S odium C hloride
1
S ulphur, A m m onia
2
D iesel F uel, F uel O il 1 to 6
3 4
Fire safety questionnaire
Flammability 1
Not flammable (Nf < 2) or low flammability (Nf >1 and T product < T flash)
G asoline, N aphtha, E thyl A lcohol, P etroleum C rude
2
H ydrogen, M ethane, H ydrogen S ulphide
Medium flammability (Nf > 1 and T flash < T product < T auto ign)
3
High flammability (Nf > 1 and T product > T auto ign)
released
3
N
M
H
quantity
2
N
L
M
1
N
N
L
Released quantity (instantaneous or per hour or inventory)
1
2
3
1
< 500 kg
2
0.5-5 ton
3
> 5 ton
flammability
P-B-v1.1
Table 3-6
© Shell Global Solutions
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RELEASE OF LIQUID THROUGH A HOLE
hole diameter [mm]
10
advised as the average case, results in released Q=2
5 mm
50 500 5000
kg/h
1 1
P-B-v1.1
10 pressure [barg]
100
© Shell Global Solutions
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HEALTH AND SAFETY explosions TWO EXPLOSION/IMPACT RISKS ARE CONSIDERED: 1 Vapour Cloud Explosions (VCE) ¾ VCE possibility (flammable cloud and congested area) ¾ released vapour mass (instantaneous, per hour) ¾ matrix to determine VCE class 2 Other impact/high pressure risks ¾ high pressure equipment ¾ failure causing flying debris ⇒ MAXIMUM OF THE TWO IS EXPLOSION CLASS (MAX E)
P-B-v1.1
© Shell Global Solutions
51
EXPLOSION detailed H & S questionnaire
Table 3-7 VCE consequence questionnaire VCE possibility
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
P-B-v1.1
1
None; no release of an explosive cloud
2
Low; release of an explosive cloud in an open area
3
Medium; release of an explosive cloud in a medium congested area (some obstacles present)
4
High; release of an explosive cloud in a heavily congested area (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
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RELEASE OF GAS through a 3 mm hole C1-C2 and H2 Release rate [kg/h]
1000
100 C1-C2 (@ 50 C) H2 (@ 50 C)
10 0
P-B-v1.1
50
100 150 Pressure [bara]
200
© Shell Global Solutions
250
53
RELEASE OF LPG THROUGH A 3 MM HOLE Released quantity [kg/h]
2500 2000 1500 1000
C3 @ 50 C
C3 @ 100 C C4 @ 50 C
500
C4 @ 100 C
0 0
P-B-v1.1
50
100 150 Pressure [bara]
200
© Shell Global Solutions
250
54
EXPLOSION & HP detailed H & S questionnaire Table 3-8 Other explosion and high pressure equipment consequence questionnaire
P-B-v1.1
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)
© Shell Global Solutions
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HIGH PRESSURE CONSEQUENCE OF GAS PIPES
pipe diameter [m]
10
5 50
PxV bar m3
500
1
0.1 1
P-B-v1.1
10 pressure [barg] © Shell Global Solutions
100
56
HEALTH AND SAFETY toxic effects TWO PARAMETERS DETERMINE TOXIC CONSEQUENCE: ¾ Toxicity – NFPA “health” index, 0 ≤ Nh ≤ 4 ¾ Concentration – four levels: < 1000 ppm, …, > 10% ⇒ MATRIX TO DETERMINE TOXIC CLASS (MAX E)
P-B-v1.1
© Shell Global Solutions
57
TOXIC RELEASES detailed H & S questionnaire Table 3-10 Toxic consequence questionnaire Toxicity
Nh
Products
0
Diesel
1
Butane, Gasoline
2
CO, benzene, Ethylene Oxide
1
Not toxic (Nh≤1) or low toxicity (Nh≤3 and conc. < 100 ppm).
3
H2S, chlorine, Ammonia, Sulphuric Acid, Phenol
2
Medium toxicity (Nh=2)
4
3
High toxicity (Nh=3)
Hydrogen Fluoride (HF), Hydrogen Cyanide
4
Extreme toxicity (Nh>3)
Concentration (in ppm or % volume)
P-B-v1.1
Table 3-9 Toxicity index, Nh, examples
Concentration
4
N
H
E
E
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
© Shell Global Solutions
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HEALTH AND SAFETY mitigation TWO FACTORS DETERMINE MITIGATION: 1
Exposure ¾
2
Frequency of and exposure time in hazardous zone
Possibility to avert the hazardous situation ¾
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)
P-B-v1.1
© Shell Global Solutions
59
MITIGATION detailed H & S questionnaire Table 3-11 Mitigation questionnaire Exposure
Possibility
3
-1
0
0
to avert
2
-1
-1
0
danger
1
-2
-1
-1
1
2
3
Exposure
P-B-v1.1
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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60
ENVIRONMENT TWO EFFECTS ARE CONSIDERED: 1
Liquid spills (max E) ¾ toxicity ¾ Released quantity (or inventory) ¾ location (within / outside fence) ¾ surface (possibility to reach surface and/or ground water
2
Gas emissions (max M) ¾ Type (volume and how harmful) ¾ Effects (complaints) ⇒ MAXIMUM OF TWO IS ENVIRONMENT CLASS
P-B-v1.1
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61
ENVIRONMENTAL simple questionnaire Table 3-13 Simple environment questionnaire Severity Consequence description rating Liquid spills 1 2 3 4 5
1 2 3
P-B-v1.1
Failure mode leads to a liquid spill with: N No or negligible environmental damage L Minor environmental damage M Localised environmental damage H Major environmental damage E Massive environmental damage Gas emission N L M
Failure mode leads to: No or small harmful release Small harmful release leading to many complaints or large Large harmful release leading to many complaints
© Shell Global Solutions
62
ENVIRONMENTAL detailed questionnaire Location Table 3-14 Liquid spills questionnaire
0
Contamination remains inside fence
Environmental toxicity
1
(Part of) contamination is outside fence
1 2 3
Not harmful to environment (e.g. water) Harmful but not toxic (e.g. most alkanes) Harmful and toxic (e.g. drins)
Surface of spill 0
No chance that spilled liquids will reach outside fence surface or ground water
1
There is a possibility that spilled liquids will reach outside fence surface or ground water
Released quantity ( or inventory)
P-B-v1.1
1
< 500 kg
2
0.5 - 5 ton
3
5 - 50 ton
4
> 50 ton
Quantity
4
N
H
E
3
N
M
H
2
N
L
M
1
N
N
L
1
2
3
Toxicity
© Shell Global Solutions
63
ENVIRONMENTAL detailed questionnaire Table 3-15 Gas emission questionnaire Type of release 3
large (> 1000 normal m3 ) and harmful
2
small and harmful
Type of
3
L
M
1
other
Release
2
N
L
1
N
N
1
2
Effect
P-B-v1.1
Effect
1
No or few complaints
2
Many complaints or is to be reported to the Authorities.
© Shell Global Solutions
64
DETERMINATION OF THE CONSEQUENCE OF FAILURE - Summary •
DIRECT
•
SIMPLE QUESTIONNAIRE ¾
•
P-B-v1.1
compliant with HSE descriptions
DETAILED QUESTIONNAIRE ¾
provide guidance and consistency
¾
useful if limited HSE experience is available
¾
mechanistic ⇒ keep thinking
¾
seek specialist advice in cases of doubt or high criticality
© Shell Global Solutions
65
DETERMINE INSPECTION SCOPE DETERMINE FAILURE CHARACTERISTIC FAILURE CHARACTERISTIC:
AGE-RELATED
THINNING
Determine Susceptibility based on the ratio: Actual corrosion rate/design corrosion rate
CREEP
Determine Susceptibility based on the operating conditions
MAX. INSP. INTERVAL = RL X INTERVAL FACTOR ADVISED METHODS AS PER DEGRADATION MODULE, EXTENT PER CRITICALITY LEVEL
P-B-v1.1
FAILURE CHARACTERISTIC:
NON AGE-RELATED - CRACKING - H-ATTACK - MECHANICAL
Determine Susceptibility based on API Technical Modules Fitness for Service study
MONITORING = TABLE
StF H M L N
CoF E H M L N
CRITICALITY
ADVISED MONITORING BASED ON DEGRADATION MODULE, EXTENT PER CRITICALITY LEVEL © Shell Global Solutions
CONFIDENCE RATING
66
CONFIDENCE RATING • •
INDICATOR FOR CONFIDENCE IN FORECAST OF DEGRADATION RATING - very low to very high – REFLECTS: ¾ stability/predictability of degradation ¾ number and quality of previous inspections ¾ process stability
⇒ BETTER CONFIDENCE YIELDS LONGER INSPECTION INTERVALS
P-B-v1.1
© Shell Global Solutions
67
CALCULATION OF INSPECTION INTERVAL for age-related degradations susceptibility to failure (questionnaire)
consequence of failure (questionnaire) - inspection records - experience - judgement
matrix
CONFIDENCE RATING
CRITICALITY
corrosion allowance corrosion rate REMNANT LIFE
matrix multiply X
INTERVAL FACTOR
MAXIMUM MAXIMUM INSPECTION INSPECTION INTERVAL INTERVAL (in (in years) years) P-B-v1.1
© Shell Global Solutions
68
AGE-RELATED DEGRADATION - inspection interval factor function of Criticality and Confidence Rating Inspection Interval Factor for
Medium Confidence Rating Critica lity E H M L N
Inte rva l Fa ctor 0.2 0.3 add or 0.4 subtract 0.5 0.6
Adjustment of interval factor based on Confidence Rating
Confidence Rating VH - Very high H - High M - Medium L - Low VL - Very Low
Adjustment factor + 0.2 + 0.1 0 -0.1 -0.2
Scoring points for adjustment factor with medium confidence as starting point. Maximum adjustment +/- 0.2
Description Degradation mechanism is stable and properly controlled Multiple reliable inspections have been carried out Relevant process parameters are reliably monitored P-B-v1.1
Score SCORE YES Int. NO + 0.1 0 -0.1 + 0.1 0 -0.1 + 0.1 0 0 © Shell Global Solutions
add /su to/ btract f ME r o m DIU M
69
INTERVAL FACTORS for age-related degradations CONFIDENCE RATING
P-B-v1.1
CRITICALITY
Very Low
Low
Medium
High
Very High
E
0
0.1
0.2
0.3
0.4
H
0.1
0.2
0.3
0.4
0.5
M
0.2
0.3
0.4
0.5
0.6
L
0.3
0.4
0.5
0.6
0.7
N (review only)
0.4
0.5
0.6
0.7
0.8
© Shell Global Solutions
70
MAXIMUM INSPECTION INTERVAL WALL THICKNESS t new
INSPECTIONS REMNANT LIFE X
X X
t (min)
MAXIMUM INSPECTION INTERVAL
MINIMUM ALLOWABLE THICKNESS
LIFETIME IN YEARS
P-B-v1.1
© Shell Global Solutions
71
INSPECTION COVERAGE (PERCENTAGE) age-related degradation CONFIDENCE RATING CRITICALITY VERY LOW LOW
MEDIUM
INTOLERABLE
REDESIGN
EXTREME
HIGH
VERY HIGH
80-100% 25-100%
HIGH
5-25%
MEDIUM LOW NEGLIGIBLE
5-25% 0-5%
Ö SELECTION OF PROPER NDT-TECHNIQUE VIA SHELL NDT HANDBOOK
P-B-v1.1
© Shell Global Solutions
72
MONITORING SCHEME for non age-related degradations susceptibility to failure (questionnaire)
consequence of failure (questionnaire)
matrix CONFIDENCE RATING
CRITICALITY
REDESIGN
– PROCES DESIGN – MECHANICAL DESIGN
P-B-v1.1
NO
IMPLEMENT YES MONITORING
matrix
ACCEPTABLE?
– PROCESS MONITORING – OPPORTUNITY INSPECTIONS
© Shell Global Solutions
73
4 3
RBI StF
IPF DR
RCM ETBF
HIGH
0 - 0.5 y
0 - 0.5 y
MEDIUM 0.5 - 4 y
0.5 - 4 y
2
LOW
4 - 20 y
4 - 20 y
1
NEGL.
> 20 y
> 20 y
CONSEQUENCE CATEGORY
PROBABILITY CLASS
RRM CRITICALITY MATRIX for non age-related degradation
ECONOMICS (USD)
RRM CRITICALITY CLASS L Additional L process N monitoring NOTNrequired
HNOT acceptable E for nonXage-relatedX M
degradation mechanisms H E
L
M
H
E
N
L
M
H
SLIGHT DAMAGE MINOR DAMAGE LOCAL DAMAGE MAYOR DAMAGE 1-10M 0.1-1M 10-100K 10M MULTIPLE FATALITIES
HEALTH & SAFETY
SLIGHT INJURY
ENVIRONMENT
SLIGHT EFFECT
MINOR EFFECT
LOCALISED EFFECT
MAYOR EFFECT
MASSIVE EFFECT
NEGLIGIBLE 1
LOW 2
MEDIUM 3
HIGH 4
EXTREME 5
CONSEQUENCE CLASS
MINOR INJURY MAYOR INJURY SINGLE FATALITY
STF (RBI): Susceptibility to Failure X = Intolerable E = DR (IPF): Demand Rate H = High M = ETBF (RCM): Estimated Time Between Failures L = Low N = P-B-v1.1
X
© Shell Global Solutions
Extreme Medium Negligible 74
CONFIDENCE RATING non-age related degradation Confidence Rating VH - Very high H - High M - Medium L - Low VL - Very Low
Adjustment factor + 0.2 + 0.1 0 -0.1 -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
+ 0.1
0
0
Reliable inspections were carried out P-B-v1.1
© Shell Global Solutions
75
MONITORING AND INSPECTION PLAN for non age-related degradations CONFIDENCE RATING CRITICALITY
VERY LOW
LOW
MEDIUM
HIGH VERY HIGH
INTOLERABLE EXTREME HIGH
DESIGN AND/OR PROCESS CHANGE REQUIRED
MEDIUM LOW NEGLIGIBLE
P-B-v1.1
MONITORING AND OPPORTUNITY INSPECTION
IMPROVE MONITORING NO INSPECTION/PROCESS MONITORING REQUIRED
© Shell Global Solutions
76
PROCESS MONITORING non-age related degradations
P-B-v1.1
•
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.
© Shell Global Solutions
77
INSPECTION/MONITORING TIMING? •
AGE-RELATED DEGRADATIONS - INSPECTIONS ¾
Calculate Remnant Life
¾
Apply Interval Factor: Max. inspection interval –
•
NON AGE-RELATED DEGRADATIONS - MONITORING ¾
Apply table to check if monitoring is required/acceptable: –
¾
P-B-v1.1
based on Confidence and Criticality Rating
monitoring scheme (+ opportunity inspections)
Based on Confidence and Criticality Rating
© Shell Global Solutions
78
INSPECTION TASKS negligible criticality
CRITICALITY MATRIX intolerable criticality
LOW/MEDIUM/HIGH & EXTREME CRITICALITY
rectify
‘no’ inspection RECTIFY IF REQUIRED
NON-AGE RELATED DEGRADATIONS
CONFIDENCE RATING
PROCESS MONITORING AND OPPORTUNITY INSPECTION
AGE RELATED DEGRADATIONS
CONFIDENCE RATING REMNANT LIFE
INFORMATION FROM DEGRADATION MODULES OR NDT HANDBOOK
INSPECTION INTERVAL NON-INTRUSIVE/INTRUSIVE
INSPECTION/MONITORING TASKS
P-B-v1.1
© Shell Global Solutions
79
Shell Global Solutions
BACK-UP SLIDES
P-B-v1.1
© Shell Global Solutions
80
NDT TECHNIQUES - see NDT Handbook •
•
•
•
P-B-v1.1
INTERNAL WALL THINNING ¾ internal corrosion ¾ erosion ¾ cavitation ¾ weld corrosion EXTERNAL WALL THINNING ¾ external corrosion ¾ corrosion under insulation CRACKING ¾ fatigue ¾ stress corrosion cracking ¾ wet hydrogen cracking OTHER ¾ creep ¾ hot hydrogen damage ¾ high temperature embrittlement
UT, RT, MFL, LRUT, PET UT, RT, MFL, LRUT, PET UT, RT, MFL, LRUT, PET UT, RT VT VT,RT,TT,RTR, PET UT, PT, MT, ET, TOFD, AET UT, PT, MT, ET, TOFD, AET UT, PT, MT, ET, TOFD, AET DM, R, PT, MT, UT MT, R, UT MT, R, UT
© Shell Global Solutions
81
FEEDBACK/REVIEW
P-B-v1.1
•
VALIDATION AND UPDATING OF THE PLANT INTEGRITY DATABASE: ¾ after each maintenance and inspection shutdown ¾ at the implementation of plantchanges ¾ at deviations of operating conditions
•
YEARLY REVIEW BY RBI-TEAM TO ESTABLISH: ¾ actual condition and fitness for purpose ¾ degradation mechanism and -rate ¾ confidence rating
•
UPDATE INSPECTION PLAN, IF REQUIRED
© Shell Global Solutions
82
RBI METHODOLOGY
P-B-v1.1
•
REVIEW THE OPERATING CONDITIONS OF THE PLANT ¾ past/present/future operating conditions ¾ process monitoring ¾ main changes from design
•
REVIEW MATERIALS OF CONSTRUCTION ¾ check materials vs process conditions
•
DEFINE CORROSION LOOPS ¾ similar process conditions/materials/degradations
•
DO THE S-RBI STUDY FOR EACH CORROSION LOOP ¾ (following slide)
•
INTEGRATE RESULTS IN AN OVERALL WORKPLANNING © Shell Global Solutions
83
S-RBI STUDY FOR A CORROSION LOOP • • • • • • • • • •
Define the Corrosion Loop Describe process conditions Establish the “Operating Window” List Items in the loop ¾ 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
P-B-v1.1
© Shell Global Solutions
84
DEGRADATION MECHANISMS • • • • • • • • •
P-B-v1.1
Internal corrosion (general) ¾ Sulphur, TAN, Acids, H2S External corrosion ¾ CUI, ESCC Creep Stress Corrosion Cracking Embrittlement Fatigue - thermal Fatigue - mechanical Erosion Hydrogen attack
AGE - RELATED DEGRADATIONS
NON AGE - RELATED DEGRADATIONS
© Shell Global Solutions
85
Degradation
AGE-RELATED DEGRADATIONS VS NON AGE-RELATED DEGRADATIONS (1)
AGE-RELATED
Time
P-B-v1.1
© Shell Global Solutions
86
Degradation
AGE-RELATED DEGRADATIONS VS NON AGE-RELATED DEGRADATIONS (2)
AGE-RELATED NON AGE-RELATED E.G. SCC Time P-B-v1.1
© Shell Global Solutions
87
CAUSTIC SODA SERVICE DIAGRAM C
Temperature (C)
B
A
Concentration NaOH, % weight P-B-v1.1
© Shell Global Solutions
88
SUSCEPTIBILITY TO FAILURE BY SSC 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.
Table S1-3 Environmental
(1)
P-B-v1.1
Susceptibility to SSC
As-welded
PWHT
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
Actually tested as Vickers or converted from portable techniques, e.g. Equotip, Microdur etc.
© Shell Global Solutions
89
FATIGUE MONITORING (PROPOSAL) monitoring/inspection interval(s) CONFIDENCE RATING CRITICALITY VERY LOW LOW
MEDIUM
INTOLERABLE
SEE NOTE
EXTREME
1 DAY
VERY HIGH
3 DAYS 1 WEEK
HIGH
HIGH
1 MONTH 2 MONTHS
MEDIUM LOW NEGLIGIBLE
NO INSPECTIONS
NOTE:
P-B-v1.1
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. © Shell Global Solutions
90
4 3
RRM CRITICALITY CLASS
RBI StF
IPF DR
RCM ETBF
HIGH
0 - 0.5 y
0 - 0.5 y
L
H
E
X
X
MEDIUM 0.5 - 4 y
0.5 - 4 y
L
M
H
E
X
2
LOW
4 - 20 y
4 - 20 y
N
L
M
H
E
1
NEGL.
> 20 y
> 20 y
N
N
L
M
H
CONSEQUENCE CATEGORY
PROBABILITY CLASS
RRM CRITICALITY MATRIX
ECONOMICS (USD)
SLIGHT DAMAGE MINOR DAMAGE LOCAL DAMAGE MAYOR DAMAGE 1-10M 0.1-1M 10-100K 10M
© Shell Global Solutions
Extreme Medium Negligible 91
ALLOWABLE PIPING VIBRATION LEVELS Vibration Amplitude, mils peak to peak
1,000.00
SEVERITY OF VIBRATION
ZONE 1
100.00
Danger Correction
2 3
10.00
Marginal Design Threshold of perception
1.00
ZONE 4 0.10 1
10
100
1000
Vibration Frequency, Hz P-B-v1.1
© Shell Global Solutions
92
S-RBI AS PART OF RRM main changes • • • • • •
P-B-v1.1
CONSEQUENCE OF FAILURE ¾ new questionnaire, identical for S-RBI, S-RCM and IPF SUSCEPTIBILITY TO FAILURE ¾ new questionnaire AGE AND NON-AGE RELATED DEGRADATIONS ¾ different approach TECHNICAL MODULES ¾ give guidance to StF ratings CONFIDENCE RATING INTERVAL FACTORS
© Shell Global Solutions
93
StF - CORROSION RATES design life 20 years
P-B-v1.1
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
25 mm dia
Cracking
- small crack, < 5 mm - medium size crack, < 25 mm - large crack, > 25 mm - through-the-wall
Rupture © Shell Global Solutions
115
PROBABILITY OF FINDING LOCALIZED CORROSION via Spot Thickness measurements - with replacement Number of thickness readings
1% area 2% 15
5% 10%
10
25% 50%
5
75% 90% 0
20
40
60
80
100
Probability of finding localized corrosion (%) P-B-v1.1
© Shell Global Solutions
116
STATISTICAL SAMPLING General corrosion on surface area 200
Sample size
160 120 80 90 95 80 50
40 0
0.00
98% Confidence
0.10
0.20
Proportion corroded
P-B-v1.1
© Shell Global Solutions
117
PIPING REJECTION THICKNESSES (1) •
• • •
P-B-v1.1
Piping classes have 1 or 3 mm Corrosion Allowance (CA): ¾ 11010 has 1 mm CA for 150 lbs conditions ¾ 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: ¾ spreadsheet ¾ table ¾ minimum thickness for mechanical stability
© Shell Global Solutions
118
PIPING REJECTION THICKNESSES (2) - Available schedule/thickness - CA, Corrosion Allowance - Plate/Pipe tolerance - DT, Design Thickness
corrosion
- Tmin Minimum Allowable Thickness - Tmin for single pit
P-B-v1.1
© Shell Global Solutions
119
PIPING REJECTION THICKNESSES (3) corrosion
wall thickness reduction Residual Corrosion Allowance
Tmin DESIGN
Fitness for Purpose (FFP) study
extra CA
Localized pitting (FFP or Code) Residual wall thickness
P-B-v1.1
© Shell Global Solutions
120
HEAT EXCHANGER TUBE - CA ? •
Internal (tube side) corrosion ?
•
External (shell side) corrosion ?
•
Corrosion Allowance CA ?
External corrosion
WT
CA = wt ? 50/50 Int./Ext.
P-B-v1.1
Internal corrosion
© Shell Global Solutions
121
MINIMUM REQUIRED WALL THICKNESS max. 250°C
Pressure
Pipe size
DN 25 DN50 DN80 DN100 DN150 DN200 DN250 DN300 DN350 5 barg 10 15
2mm
20
1) B31.3 calculation, CS A106 B or API 5L-B 2) Max. pipe span as per memo (check), filled with water and weight in the middle 3) Full vacuum 4) NOT valid where additional stresses from expansion etc. occur
4mm
25 30
4mm
5mm
4mm
5mm
5mm
4mm
5mm
6mm
7mm 9mm
3mm
40 50
4mm
5mm
6mm
8mm
60
5mm
6mm
8mm
9mm 10mm
4mm
6mm
8mm
9mm 11mm 12mm
4mm
5mm
8mm 10mm 12mm 14mm 16mm
5mm
7mm
9mm 12mm 15mm 18mm 20mm
75 100 125
P-B-v1.1
4mm
4mm
© Shell Global Solutions
122
NDT MEASUREMENTS - PLUGS
plug
P-B-v1.1
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123
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