In Service Inspections Avoiding Disasters!

David Lake

RBI’s are Important

• Cost effective method of preventing failure?

• Method of meeting statutory obligations

• Duty of Care

• Prevention of DISASTER?

• ALL stages of RBI planning and implementation must be done WELL by PEOPLE!

Explosion de gas en Reynosa, Tamaulipas

Disasters are infrequent BUT!

• Varanus Island WA • Corrosion -was it visible –under coating –

Inspected?

• Estimated to cost the WA economy $billions

• +

• Alcoa sues Apache Energy over gas pipeline blast ........... Consequences...

The RBI Process

1. Analysis

• Process / product initiated risk

• Equipment risk

• Environmental condition induced risk

• People / Human error

Then assess the likelihood – severity --- etc to categorise the risk into high/medium/ low

The RBI Process

2. Inspection and test plan

Cost versus Risk “Appetite” now key elements

• Process parameter monitoring

• Visual inspection

• NDT is most often used where the potential risk has been assessed as medium or high

• Results are “plugged” into the model

• Iterative process

How much can you Inspect?

• Coverage vs. Cost

• How do we inspect cost effectively where we cant see?

• Permanent quick recording / reporting important to measure “change” accurately

RBI NDT Inspections

• Only undertaken where assessed risk is med/high ?

• Most likely a statistical sampling process is used, therefore results MUST BE RIGHT!

• NDT equipment is very capable and available

Cost vs. Value? Global Inspections –

Visual (VT cert?)

Asset Management

Global Inspections – Acoustic Emission

Sensors

Located AE

AE Signal A

mplit

ude

Threshold

Duration

Rise time Decay time

Event Counts = 7

Time

AE Testing – Tank Set Up

Sensors

Tank floor results

Global inspection techniques

• Thermography

• Long wave Ultrasonics

CUI • Pulsed eddy current

• Radiography

• MFL

• And others

Risk?

• The equipment is NOT “automatic”

• Even the simple UT thickness check can give erroneous results in the wrong hands

• The NDT technician is critical, to getting reliable accurate results

Scanning

• A-Scan

• S-Scan

• C-Scan

• B-Scan

• D-Scan

• Advanced Views (polar/merged/etc)

Phased Array Ultrasonics “quick?”

Consequences

• No defect indications? Where they exist

• False sense of security – miss one miss all?

• Failure potential remains BUT.......

• Indications found where they don’t exist $$$

• Sizing wrong or rate of change ......

What certification is best?

• ISO9712 + NATA? (ISO 17025)

• AINDT trained/certified to Australian standards

• PCN (/CSWIP) and other ISO 9712 compliant schemes

Advanced skills

Difficult

The Future

• The Risk In Risk Management, will be the PEOPLE!

• Select best methods

• Get the greatest coverage for your $

• Get accurate information for a statistical analysis approach

Thankyou for Listening

Questions?