Shell RBI Methodology

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


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


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


4

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

5

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


6

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


7


S-RBI METHODOLOGY

P-B-v1.1


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)


10

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


11

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

12

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


13

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!


14

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


15

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

16

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


17

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


18

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


19

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 <10K 10-100K 0.1-1M 1-10M DAMAGE >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


20

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


PROBABILITY CLASS


ECONOMICS (USD)

SLIGHT DAMAGE MINOR DAMAGE LOCAL DAMAGE MAJOR DAMAGE EXTENSIVE <10K 10-100K 0.1-1M 1-10M DAMAGE >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


21


SUSCEPTIBILITY TO FAILURE ASSESSMENT

P-B-v1.1


22

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.


23

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.


24

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

25

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

26

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


27

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


28

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


29

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


30

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<5%wt?

L Low Susceptibility

Yes

Steamed out?

Heat traced?

Medium Susceptibility

No

No

Plots in Area “A”?

No

Yes

M

Temperature

No

Steamed out?

Yes

No

NaOH conc<5%wt?

H High Susceptibility

Yes

Yes

Medium Susceptibility M

No

Not Susceptible N

P-B-v1.1


31

StF - NON AGE-RELATED DEGRADATIONS (2) NAR

7 Low Temp. Embrittlement

Operating or upsets outside the limits of DEP 30.10.02.31 Gen.

H

(No cat. M)

NAR

P-B-v1.1

8 High Temp. Embrittlement

Operating or upsets within the limits of DEP 30.10.02.31 Gen.

L

Not susceptible under any foreseeable conditions

N

Operating in the embrittlement range and no S/D precautions

H

Design or upsets in the embrittlement range and no S/D precautions

M

Design and operation below the embrittlement range or S/D precautions

L

Not susceptible under any foreseeable conditions

N


32

StF - NON AGE-RELATED DEGRADATIONS (3) NAR

9 High Temperature Hydrogen Attack

NAR 10 Erosion (non protected system)

Operating/upset conditions above the Nelson curve limit (API 941)

H

Operating conditions between the Nelson curve limit and 20 °C below (API 941)

M

Operating conditions are 20 - 50 °C below the Nelson curve limit (API 941)

L

Operating conditions are > 50 °C below the Nelson curve limit (API 941) or Material is not susceptible under any foreseeable conditions

N

Flow velocity is much higher than design and/or much larger H amounts of solids/droplets present Flow velocity is higher than design, and/or solids/droplets higher than design

M

Flow velocity is per design or less, solids/droplets loading as L per design or less No foreseeable occurrence of erosion

P-B-v1.1


N

33

StF - DEGRADATION MODULES for further information •

Based on the API BRD 581 Technical Modules ¾

•

15 Modules available for all major degradation mechanisms (and more under development) ¾

¾

P-B-v1.1

modified where required to reflect SIOP experience

general corrosion – acids – water – etc. CUI, H2S, H2 attack, SCC, etc.


34


CONSEQUENCE OF FAILURE (CoF) ASSESSMENT

P-B-v1.1


35

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 process and equipment data

•

USE TOP-DOWN APPROACH ¾

P-B-v1.1

Use 3 to set the levels for the loop, for main items


36

DIRECT ASSESSMENT OF CONSEQUENCE OF FAILURE

ECONOMICS

HEALTH & SAFETY

NEGLIGIBLE

LOW

MEDIUM

HIGH

EXTENSIVE

<10 k$ NO DISRUPTION

10 - 100 k$ BRIEF DISRUPTION

0.1 - 1 M$ PARTIAL SHUTDOWN CAN BE RESTARTED

1 - 10 M$ PARTIAL OPERATION LOSS (2 WEEKS)

>10 M$ SUBSTANTIAL/ TOTAL LOSS OF OPERATION

NO/SLIGHT INJURY FIRST AID/MEDICAL TREATMENT

MINOR INJURY MAJOR INJURY SINGLE FATALITY LOST TIME INCLUDING INCLUDING INCLUDED PERMANENT PERMANENT TOTAL DISABILITY MAXIMUM 1 WEEK PARTIAL DISABILITY

NO/SLIGHT EFFECT MINOR EFFECT LOCALISED EFFECT LOCAL DAMAGE CONTAMINATION, AFFECTING ENVIRONMENT WITHIN FENCE NO PERMANENT NEIGHBOURHOOD EFFECT

MAJOR EFFECT EXTENSIVE RESTAURATION REQUIRED

MULTIPLE FATALITIES

MASSIVE EFFECT SEVERE DAMAGE NUISANCE IN LARGE AREA

Î MAXIMUM CLASS IS GOVERNING P-B-v1.1


37

ECONOMICS •

•

•

P-B-v1.1

PRODUCTION LOSS ¾

deferred income (no or downgraded product)

¾

product wasted (flared or spilled)

REPAIR COSTS ¾

repair/re-install item

¾

fixed contractor costs (lump sum)

LABOUR


38

DIRECT ASSESSMENT OF ECONOMIC CONSEQUENCES Class

Potential Im pact

Description

N

Slight dam age < 10 kUSD

N o disruption to operation

L

M inor dam age 10-100 kUSD

Brief disruption

M

Local dam age 0.1-1 M USD

Partial shutdown that can be restarted

H

M ajor dam age 1 - 10 M USD

Partial operation loss (2 w eeks shutdown)

E

Extensive dam age > 10 M USD

Substantial or total loss of operation

definitions as given in the HSE RAM P-B-v1.1


39

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


40

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


41

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


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


43

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.


44

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


45

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


46

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


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)


48

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


49

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


50

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


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


52

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


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


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*V<5 bar m3

L

gas present and 5 ≤ p*V ≤ 50 bar m3

M

gas present and 50 < p*V < 500 bar m3

H

gas present and p*V>500 bar m3 or failure causing some flying debris (solid particles)

E

failure causing major flying debris (solid particles)


55

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


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


58

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


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)


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


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


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


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.


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


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


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


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


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


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


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


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


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 <10K

EXT. DAMAGE >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


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


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


P-B-v1.1

MONITORING AND OPPORTUNITY INSPECTION

IMPROVE MONITORING NO INSPECTION/PROCESS MONITORING REQUIRED


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.


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


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


79


BACK-UP SLIDES

P-B-v1.1


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


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


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


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


85

Degradation

AGE-RELATED DEGRADATIONS VS NON AGE-RELATED DEGRADATIONS (1)

AGE-RELATED

Time

P-B-v1.1


86

Degradation

AGE-RELATED DEGRADATIONS VS NON AGE-RELATED DEGRADATIONS (2)

AGE-RELATED NON AGE-RELATED E.G. SCC Time P-B-v1.1


87

CAUSTIC SODA SERVICE DIAGRAM C

Temperature (C)

B

A

Concentration NaOH, % weight P-B-v1.1


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.


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


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


PROBABILITY CLASS

RRM CRITICALITY MATRIX

ECONOMICS (USD)

SLIGHT DAMAGE MINOR DAMAGE LOCAL DAMAGE MAYOR DAMAGE 1-10M 0.1-1M 10-100K <10K

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

EXT. DAMAGE >10M


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


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


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

<0.02

<0.07


94

CORROSION ALLOWANCES special cases

P-B-v1.1

•

STAINLESS STEEL AND ALLOYS ¾ 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 ¾ wall thickness is CA ¾ 50% for inside, 50% for outside, if leaks are accepted ¾ sometimes users want e.g. 0.5 mm minimum for pressure containment. ¾ higher minimum thickness can be agreed. © Shell Global Solutions

95

HEAT EXCHANGER DEFINITIONS Shell side

Tube side Head (He)

Shell (Sh) Tube outside (To)

Tube inside (Ti)

P-B-v1.1


96

SUB TAGS & TAG GROUPS C-201 TOP

16” P1004 3117Y

SUB - TAGS

4” P1005 3117Y 24” P1002 3117X

“DRY OH PIPING” Tags P1004, P1005, P1006

C-201

TAG GROUPS

C-201 Bottom “WET PIPING” tags P1002, P1003 12” P1003 3117X P-B-v1.1


97

FAILURE

P-B-v1.1

•

TERMINATION OF THE ABILITY OF AN ITEM TO PERFORM A REQUIRED FUNCTION: ¾ corrosion allowance lost ¾ (after FFP) below minimum required thickness ¾ leak to outside (or internal) ¾ crack detected (beyond tolerable) ¾ deformation (beyond tolerable) ¾ extreme case: rupture – brittle or ductile

•

NORMAL DESIGNS - “LEAK BEFORE BREAK”: ¾ warns and allows to avoid hazards


98

PLANTS risk and reliability - mechanical PLANT process conditions

+

materials DESIGN PER CODE pressure/ temperature P-B-v1.1

DEGRADATIONS

INSPECTION

MAINTENANCE

corrosion - general - pitting - Stress CC mechanical - fracture - fatigue - etc.

visual ultrasonic X-ray infrared magnetic part. dye penetrant eddy current

repair replace

pH temperature chloride level

preventive or break down timing of inspection/ monitoring tasks


99

FAILURE CLASSIFICATION CORROSION

INTER/TRANS GRANULAR

SURFACE

LOCALISED CORROSION

- pitting - crevice - galvanic - fretting - velocity (erosion)

NON-FLUCTUATING

GENERAL CORROSION

STRESS CORROSION CRACKING

DUCTILE FRACTURE

FLUCTUATING

TEMPERATURE EFFECTS

OVERLOAD

LOW

HYDROGEN EMBRITTLEMENT

P-B-v1.1

STRESS

BRITTLE FRACTURE

THERMAL

HIGH

CREEP RUPTURE

HYDRAULIC

MECHANICAL

THERMAL FATIGUE

WEAR

CAVITATION

erosion

FATIGUE CORROSION FATIGUE


OGBR MHR

100

S-RBI RELATED TOOLS Maintenance and Inspection Database

Electronic Drawings (VISIO)

Trending Software MEP/Corrosion Control Manual

S-RBI (RRM) Manual

S-RBI ANALYSIS S-RBI (RRM) Software

Statistical Recipe Book Degradation Library

P-B-v1.1

NDT Handbook

FFP Handbook © Shell Global Solutions

101

S-RBI IN COMPARISON WITH API STANDARDS (1) API 510 API 570 API RP 580

Pressure Vessel Inspection code Piping Inspection code Risk Based Inspection DRAFT

S-RBI FULLY IN LINE WITH API REQUIREMENTS • • • • • • • •

P-B-v1.1

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 © Shell Global Solutions

102

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

P-B-v1.1


103

WALL THICKNESS UT MEASUREMENTS POOR QUALITY +/– 1 mm 9

10

11 GOOD QUALITY +/– 0.5 mm

High quality UT measurements can obtain +/– 0.3 mm 9 P-B-v1.1

10 © Shell Global Solutions

11 104

DEFECT SIZES UPON FAILURE •

• • •

P-B-v1.1

Standard hole size 3 mm for gas and 3 - 5 mm for liquids for normal degradations leading to pitting and small holes; ¾ 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. © Shell Global Solutions

105

TAG NUMBERS ADVISED DETAILS:

P-B-v1.1

•

PIPING (max 25 characters) ¾ size ¾ line code 8 PL1010 CS HI INSP ¾ material ¾ insulation code ¾ authority code (if applicable)

•

EQUIPMENT ¾ TAG number ¾ insulation code ¾ authority code

V-1101 CI INSP E-302 TS Ti HI INSP © Shell Global Solutions

106

STANDARDIZED CORROSION RATES (CR) CARBON STEEL • If no corrosion detected after about 10 years: ¾ Assume detection limit of 0.5 mm, corrosion rate must be lower than 0.05 mm/yr ¾ Use this value as worst case CR until better information is available STAINLESS STEEL • If no corrosion detected after about 10 years ¾ 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) ¾ Use this value as worst case CR until better information is available

P-B-v1.1


107

STRESS CORROSION CRACKING START

No problem No Yes

Is the material of construction carbon or low alloy steel? Yes Screen for Caustic, Amine, SSC, HIC/SOHIC, Carbonate Cracking

Determine susceptibility for each potential SCC mechanism for Carbon and Low Alloy steels

No

Is the material of construction austenitic stainless steel? Yes

Do you know the cause of SCC?

Yes Screen for PTA, Cl-SCC

Determine susceptibility for each potential SCC mechanism for austenitic Stainless Steels

Increase the susceptibility for that mechanism to high

No

Have you detected SCC in this or similar service equipment?

No Determine the severity index for each potential mechanism

Increase susceptibility for all potential mechanisms to high

Determine maximum severity index

P-B-v1.1


108

thickness

MAXIMUM INSPECTION INTERVAL

t new

Inspections

X X

L to E (X) Criticality VL to VH Confidence 0.0 - 0.7 Int. Factor

H

StF

N to H Criticality VL to VH Confidence 0.1 - 0.8 Int. Factor

M

N

L

MIN. ALLOWABLE THICKNESS

t(min)

<5

20

~ 5 -10 LIFETIME IN YEARS

P-B-v1.1

40


design life 109

EFFECT OF MONITORING/INSPECTION AND/OR MITIGATION REMAINING RISK = CRITICALITY - “PREVENTIVE MEASURES” HIGH RISK

Probability

Criticality

LOW RISK Consequence

P-B-v1.1

monitoring/inspection effect Define inspection tasks to get lowest possible risk © Shell Global Solutions

110

Probability

“REMAINING” RISK TO BE AS LOW AS REASONABLY POSSIBLE (ALARP) 1. Inspection interval and coverage - based on Criticality and Confidence Rating HIGH RISK 2. Type of Inspection(s) Criticality - based on failure mode(s) 3. Location(s) to inspect - for each failure mode 4. Process Monitoring LOW RISK - where applicable (operating window) Consequence

(ALARP)

P-B-v1.1


111

FAILURE MODE & CONSEQUENCES Degradation

Failure mode

Consequence of Failure

Typical defect:

Pitting

Small leak

Leak, no significant damage Small fire (Big fire or explosion)

Hole, 3-5 mm dia System Inventory

Embrittlement

Fracture

Big fire or explosion

System Inventory

Caustic cracking SCC

Cracks

Leaks

Hole, 3-5 mm dia

General corrosion

Leak Rupture

Fire, small explosion Big fire or explosion

Hole, 3-5 mm dia System Inventory

w

w

worst case & if flammable contents

w

To avoid long discussions, general worst case failure modes are taken as default starting point (modified if required, after discussions) P-B-v1.1


112

1.6

20 years

1.4 1.2 1.0 0.8

10 years

0.6 0.4

0.14

3 years 0.12

0.08

0.06

0.04

0.0

0.10

?

0.2 0.02

Measurement Tolerance +/– , mm

YEARS TO MEASURE CORROSION

Corrosion Rate, mm/yr

P-B-v1.1


113

COST REDUCTIONS By risk reduction • By longer inspection intervals • By lower inspection cost •

from 0.1 * 5 MM to 0.001 * 5 MM ⇒ reduction = 495. 000/yr

PROBABILITY CLASS

= Freq. Reduction x CoF

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

ECONOMICS (USD) HEALTH & SAFETY ENVIRONMENT

CONSEQUENCE CLASS

P-B-v1.1

RRM CRITICALITY CLASS



Risk reduction - count total if new plant - count difference if existing plant

1.0 0.1 0.01 0.001

SLIGHT DAMAGE MINOR DAMAGE LOCAL DAMAGE MAJOR DAMAGE EXTENSIVE 1-10M 0.1-1M 10-100K <10K DAMAGE >10M SLIGHT INJURY MINOR INJURY MAJOR INJURY SINGLE FATALITY SLIGHT EFFECT

MINOR EFFECT

LOCAL EFFECT

NEGLIGIBLE 1

LOW 2

MEDIUM 3

MULTIPLE FATALITIES

MAJOR EFFECT MASSIVE EFFECT


HIGH 4

EXTREME 5

114

DEGRADATIONS AND FAILURE MODES DEGRADATION MECHANISM - General corrosion - Erosion - Hot H2-attack - Pitting corrosion - Fatigue - Creep - Stress Corrosion Cracking - Embrittlement P-B-v1.1

FAILURE MODE Wall 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, - large hole, - very large hole,

< 5 mm dia > 5 mm dia > 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


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


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


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


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


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


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


122

NDT MEASUREMENTS - PLUGS

plug

P-B-v1.1


123

Shell RBI Methodology

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