Agenda

Responsibilities, Legislation
and Guidance

Ageing Plant Methodology

Ageing Mechanisms

Management of Ageing

Summary
David Burgess, ABB Consulting, September 2012
The Challenge of Ageing Assets in the
Bulk Liquid Storage Industry
© ABB Group
August 30, 2012 | Slide 1
© ABB Group
August 30, 2012 | Slide 2
Responsibilities
As an owner, user or manager of equipment containing hazardous fluids,
you have an overriding responsibility to your employees, contractors, other
site residents, the general public, and to the environment for ensuring:
Responsibilities,

Health and Safety.

Minimum impact of operations outside the site.
Legislation and Guidance
These responsibilities are effected in terms of:

Control of Major Accident Hazards (COMAH)

Control of Hazardous Chemicals and Dangerous Substances.

Safe and reliable operation and maintenance of plant and equipment.

Avoidance of nuisance from operations.

Minimising waste and discharges.
Ref: HSE RR 509 – Plant Ageing – Management of equipment containing hazardous fluids or pressure
© ABB Group
August 30, 2012 | Slide 3
Legislation – Storage Tanks

© ABB Group
August 30, 2012 | Slide 4
Publications / Guidance
Main Hazard is the inventory of product


HSE RR 509 (2006) & RR 823 (2010). Ageing Plant

HSE Doc SPC/Tech/Gen/35. Integrity of storage tanks

HSE RR 760. Review of Storage Tank Standards

EEMUA Guide 159 & API 653. Inspection, Maintenance and Repair
of Storage Tanks

EEMUA Guide 183 – Prevention of Bottom Leakage

http://www.chemical.org.uk/non_metallic_storage_tanks.

HSE PM 75 & PM 86. Non-metallic storage tanks
Not PSSR if < 0.5 barg

HASAW Act and PUWER always apply

COMAH, IPPC and/or DSEAR (Storage of Dangerous Substances) may also
apply depending on the tank contents and location
© ABB Group
August 30, 2012 | Slide 5
© ABB Group
August 30, 2012 | Slide 6
1
Ageing plant – Definition
Tanfield railway.
Working engine and water
tanks in use since 1913
Ageing Plant
Methodology
Ageing equipment is equipment for which there is evidence or
likelihood of significant deterioration and damage taking place
since new,
or for which there is insufficient information and knowledge
available to know the extent to which this possibility exists.
Ref: HSE RR 509 – Plant Ageing – Management of equipment containing hazardous fluids or pressure
© ABB Group
August 30, 2012 | Slide 7
© ABB Group
August 30, 2012 | Slide 8
The Ageing Stage – What are the Signs?
Accumulated
d Damage
Ac
ccumulated Damage
Equipment Life – 4 Stage Model
Time
Initial
Operation
Mature
Stage
Ageing
Stage
Terminal
Stage
•Approaching design limits eg. remaining life assessment
•Evidence of significant accumulated damage
•Changes in process use
•Repairs, refits, modifications
•Deficiencies in systems and skills
Time
Ref: HSE RR 509 – Plant Ageing – Management of equipment containing hazardous fluids or pressure
Initial
Operation
Ageing
Stage
Terminal
Stage
Ref: HSE RR 509 – Plant Ageing – Management of equipment containing hazardous fluids or pressure
© ABB Group
August 30, 2012 | Slide 9
© ABB Group
August 30, 2012 | Slide 10
Four Stages of Ageing - Description
STAGE 1 - POST COMMISSIONING (‘INITIAL’)
Mature
Stage
What affects asset life?
STAGE 2 - RISK-BASED (‘MATURITY’)

Design and manufacturing faults

Operation well within design limits

Installation issues (bolting, valves, leaks)

Retained corporate knowledge of design/manufacture

Commissioning issues (over/under filling)

Ageing damage not yet significant;

Early life operating faults (training, trials)

Routine maintenance

Shake-down

Extended operating periods

Identification of potential ageing sites


First thorough examination (finger-print)
Selected inspection, by risk analysis, to confirm expectation of slow
degradation

Reducing rate of problems

Updated risk analysis from experience

Rate of damage low and predictable
•Life-limiting factors assumed at design stage
•Design quality
Design
•Quality of original fabrication & installation
Construction
•Operating within design limits
Knowledge of equipment condition e.g.
Suppliers
•Inspection of static equipment
STAGE 3 - DETERMINISTIC (‘AGEING’)

Design limits approaching

Evidence of active deterioration

Repairs, refits, modifications

Changes in process/use

Lack of full history/corporate memory

Changes in ownership; second hand plant

Quantitative NDT inspection to measure extent and rate of damage
accumulation

FFS assessment required for life extension

Degradation rate increasing - less predictable
STAGE 4 - MONITORED (‘TERMINAL’)
•Obsolescence of equipment
Accelerating and accumulating damage

Beyond design limits and known operating experience

Approaching safe operating limits

Advanced inspection and FFS required to determine residual life

Decreasing intervals between inspections

Major repairs and refits replacement needed
•Maintaining equipment in ‘fit for service’ condition

End of life based on costs of repairs or replacement and wider economic
factors
•Quality of spare parts and repairs
Inspection
•Change of equipment or operating procedure that
negates original design assumptions
Maintenance
Modifications
Asset Life Factors Across the Life Cycle
Ref: HSE RR 509 – Plant Ageing – Management of
equipment containing hazardous fluids or pressure
© ABB Group
August 30, 2012 | Slide 11
•Condition Monitoring of rotating equipment
Operation

© ABB Group
August 30, 2012 | Slide 12
2
Ageing Plant – Not us?
Current Performance on Ageing Plant
The quotes below are typical examples from organisations and individuals
that are not recognising or acting on the signs of ageing

There haven’t been any problems up to now, so the equipment is
safe, isn’t it?

We don’t have any drawings for this vessel; and we don’t know what
the material is.

It’ only
It’s
l been
b
in
i service
i for
f two
t
years so it can’t
’t be
b ageing.
i

The integrity of our equipment is separate from our safety
management.

Our equipment does not contain defects.

We maintain and inspect only equipment to meet the Pressure
Systems Regulations.
Ref: HSE RR 509 – Plant Ageing – Management of equipment containing hazardous fluids or pressure
© ABB Group
August 30, 2012 | Slide 13
Ref: IChemE Loss Prevention Bulletin 224, April 2012 - Management of Ageing Plant, S Pointer HSE
© ABB Group
August 30, 2012 | Slide 14
Types of Material Damage Mechanisms
Damage to material can be categorised into four main types:

Wall thinning.

Ageing Mechanisms



General or localised corrosion, pitting, CUI
Erosion, erosion-corrosion, scouring
Wear, abrasion, fretting
Stress-driven damage, cracking and fracture.






Fatigue damage and cracking
Creep cavitation and creep crack growth
Stress corrosion cracking (SCC)
Brittle fracture
Hydrogen cracking
Ductile tearing

Physical deformation.

Metallurgical / environmental damage.



Dents, Gouges, Buckling and Yielding
Various embrittlements – hydrogen, temper, strain age, sigma phase
Polymer ageing – UV radiation, temperature, chemical attack
Ref: HSE RR 509 – Plant Ageing – Management of equipment containing hazardous fluids or pressure
© ABB Group
August 30, 2012 | Slide 15
© ABB Group
August 30, 2012 | Slide 16
Damage Mechanisms – 2009 Data.
Damage Mechanisms – Identifying Root Causes
No of Failures
40
35
30
25
20
No
oo
of Failures
a u es
15
10
5
© ABB Group
August 30, 2012 | Slide 17
Wear
Over
Pressure
Overheating
Creep
Brittle
fracture
Mechanical
Failure
Erosion
Weld
Failure
Fatigue
SCC
Corrosion
0
© ABB Group
August 30, 2012 | Slide 18
3
External Corrosion
Corrosion under insulation

Storage tank at shell base

Local to water traps e.g. insulation support rings, wind girders

Insulated pipes to and from tank
Design Temp : 100 Deg
Baseplate Nominal Thickness : 10.0mm
Depth of Corrosion Up to 8.0mm
© ABB Group
August 30, 2012 | Slide 19
Bottom Plate Rotation – Low Cycle Fatigue
© ABB Group
August 30, 2012 | Slide 20
Non Metallic – Mechanical Properties
Material Specific Gravity Tensile Stress
(Mpa)
1.4
55
PVC
PP
PTFE
GRP
C-steel
C
steel
0.9
2.2
1.4
78
7.8
25
20
100
400
Ni Alloys
8.0
1200
Graph and Table are for indication purposes only.
Do not use figures for specific design assessment
© ABB Group
August 30, 2012 | Slide 21
© ABB Group
August 30, 2012 | Slide 22
Non Metallic tanks – condition & inspection

There are thousands in service, commonly manufactured from:

Thermoplastic (HDPE, PP, PVC etc.)

GRP (Glass Fibre + Resin Binder ie. “Derakane”, “Atlac”, “Furane”)

GRP / Plastic lined

Non Metallic tanks are much weaker than steel tanks (see previous slide)

Not “fit-and-forget” – they do have a finite life and will deteriorate

Typically limited data from manufacturer and in many cases little
appreciation by operators of need, or method of inspection

Recent Guidance by HSE in conjunction with industry experts

PM 75 – GRP vessels and tanks – advice to users

PM 86 – Thermoplastic tanks (issue due shortly)
© ABB Group
August 30, 2012 | Slide 23
Management of Ageing
© ABB Group
August 30, 2012 | Slide 24
4
Management of Ageing – Case study
Is integrity managed?
7 Key elements for the identification and management of ageing plant
Unsupported branch
fatigue failure
1. Maintenance Management Systems
(Weak procedures did not act on increasing vibration trend)
 Low pressure items often overlooked
 Identify deterioration mechanisms
 Eliminate deterioration mechanisms where possible
2. Asset Management and Integrity Systems
(Weak assessment approach that did not include dead-legs)
 Establish rate of deterioration
3. Audit and Inspection regimes
Risk
Management
 Establish Inspection frequency
4. Risk Assessment Management processes
(Not identifying risks of unsupported branch on live system)
 Prepare Written Scheme of Examination
5. Management of Change procedures
(Not recognising effects of change during modification)

6. Responsibilities and Communications
(ownership / responsibility of asset not established)
7. Training and Competence development
(Staff did not recognise potential for failure)
Planned &
Controlled
Work
 Select appropriate Inspection / NDT techniques
(Vibration / fatigue potential not picked up during inspection)

A modification had been carried
out several years before failure,
leaving a section of pipework
inadequately supported
Auditing
Competent
People
 Inspect
 Review WSE
Vibration of the unsupported
pipework had not be
noticed/reported
Reliable
Assets
ASSET
INTEGRITY
Training
Monitoring
Effective
Systems
Information
Systems
Methods
and
procedures
Ref: HSE RR 823 – Plant Ageing Study 2010
© ABB Group
August 30, 2012 | Slide 25
Do you know your critical equipment
© ABB Group
August 30, 2012 | Slide 26
Do inspection schemes include all damage mechanisms?
Consider Criticality Screening/Assessment
© ABB Group
August 30, 2012 | Slide 27
Inspection frequencies
© ABB Group
August 30, 2012 | Slide 28
Consider Risk Based Inspection (RBI)
 Codes are not
Prescriptive. Only
guidance given
New
assets
 Example:- Table from
EEMUA 159
 Other factors to consider,
listed in API 653:- nature of product
- corrosion rates
- operational regime
- prevention systems
Criticality &
Opportunity
S
Screening
i
Existing
assets
Equipment
Prioritisation
© ABB Group
August 30, 2012 | Slide 29
© ABB Group
August 30, 2012 | Slide 30
5
RBI Example - Riveted Tank

Built in 1893 >100 years old

Flammable contents – Diesel

COMAH Inventory

Significant history of repairs

Weeping at Rivets

Frequent Inspections specified

Replacement recommended
Prioritise inspection with NDT screening techniques
eg. Acoustic Emission (AE) Testing
AE sensors of tank shell plates
on a lower tank shell course
Determine the origin (location) of
active corrosion by triangulation
2
1
3
‘A: very minor
‘B’: minor
‘C’: intermediate
IV
Very active damage, open the tank.
III
Active damage, plan repair, re-test after 1 year.
II
Minor active damage, re-test after 3 years.
I
No active damage, re-test after 5 years.
n/a Should not occur at standard threshold
© ABB Group
August 30, 2012 | Slide 31
For ageing and vulnerable items in the terminal stage, the potential for defects and
leaks should be considered and planned for:

Identify potential failure scenarios based on condition eg. base leak, hole in shell.

Contingency plan for leaks / defects – options may include:
 Transfer of inventory
 Temporary repair
 Continue operation and manage leak / defect
 Shutdown
C
D
E
5
III
III
IV
IV
IV
4
II
III
III
IV
IV
3
II
II
III
III
III
2
I
I
II
II
n/a
1
I
I
II
n/a n/a
‘D’: active
‘E’: highly active.
Operational risk assessment
 Emergency plan
 Roles and responsibilities
 Materials and services
Summary

Know and understand you assets and their ageing status

Identify and manage deterioration mechanisms and look to
minimise or eliminate as many as possible / practical

Have in place a sound integrity management system

Allocate responsibility for assets within your organisation

Use an experienced and capable inspection organisation

Use the standards and guidelines available (100 years experience)

Carry out regular visual checks with own staff


B
© ABB Group
August 30, 2012 | Slide 32
Management of items in ‘Terminal Stage’ of Life

A
Plan for permanent repair / replacement
 Funding
 Resources / contracts
 Planned outage
© ABB Group
August 30, 2012 | Slide 33
Act on any defects identified to prevent further damage
Ageing assets can be managed safely and effectively
providing the methodology is understood and applied.
© ABB Group
August 30, 2012 | Slide 34
Thankyou for listening
Any Questions?
© ABB Group
August 30, 2012 | Slide 35
© ABB Group
August 30, 2012 | Slide 36
6