Safety Driven Performance Conference 2013 Supplementing Risk Basked Inspection Programs with...

Safety Driven Performance Conference 2013

Supplementing Risk Basked Inspection Programs with Integrity Operating Windows (IOWs)

Vishal Lagad - Sr. Corrosion EngineerAsset IntegrityLloyd’s Register Energy, Americas

October 9, 2013

Safety Driven Performance Conference 2013

Venue safety information

• Safety overview • Location of emergency exists

Safety Driven Performance Conference 2013

Overview

• Review plant reliability goals• IOW and RBI basics• Benefits of an IOW program• Supplementing RBI program with IOWs• Examples in refinery application• Q & A

Safety Driven Performance Conference 2013

Plant Reliability Goals

• Ensure equipment performs it’s required functions for a specific time period

• Maximize equipment availability

• Optimize maintenance

• Reduce risk and potential for leak/rupture

• Provide early recognition of equipment risks due to process deviations

• In short - No surprises!

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Risk Based Inspection - RBI

• Uses past operating conditions and inspection data to make future predictions

• Captures risk at a snap shot in time

• What happens when process conditions change?

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Existing Industry Standards

• Importance of monitoring operating conditions

• API RP 580 Section 6.4

• “It may be worthwhile to monitor key process parameters to determine whether operations are maintained within boundaries”

• API 510 Section 6.2

• “The likelihood of failure assessment should be repeated each time equipment or process changes are made”

• API 584 – Best practices, guidelines for IOWs

• Second Draft in review

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Process & Operational Impact

• Processes are not always stable• Feedstock variations• Upsets

• When changes to operating conditions affect key process variables

• New damage mechanisms may be introduced • Corrosion rates may accelerate

• These excursions are typically unaccounted and their impact not considered

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IOW Concepts

• IOWs are allowable operating limits for a process variable

• Established to manage corrosion and other damage mechanisms

• Different from SOL, Alarms for Pressure integrity (MAWP etc.)

• Requires a response within established timeframes if limit is exceeded

• Failure to bring the operating condition within the IOW limit within established timeframe will result in damage to the equipment outside of acceptable limits

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IOW Limits

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Early failure

Expected Remaining Life

IOW – Standard High

IOW – Critical High / SOL

Acceptable Risk LevelExpected Risk Profile

Time (years)

Rem

aini

ng

Life

(yea

rs)

Risk

Tem

pera

ture

Actual Remaining

Life

0 4 10 25

Breached IOW level for 3 months

An Illustration

Safety Driven Performance Conference 2013

Benefits of an IOW Program

• Proactive approach to managing reliability and risk

• Real time notification of an increased risk

• Allows for timely intervention when process conditions change

• Extends operating life of an asset

• Enhances safety

• Cost savings - reduced inspection costs and capital expenditures

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IOW Implementation Team

Multidisciplinary team of SME’s

•Corrosion Engineer / specialist

•Process Engineer

•Reliability Engineer / RBI specialists

•Operations personnel

•Plant inspector

•Others – chemical treatment vendor, license technology specialists

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Steps in Establishing an IOW Program

• Collect and review data

• Create corrosion loops or circuits

• Corrosion study

• Damage mechanism review

• Establish IOW Limits

• Implement IOW program

• Identify actions and responsibilities

• Process historian and Alarm configuration

Collect and Review Data

Create Corrosion Circuits / Loops

Corrosion Study and IOW Limits

Implement IOW Program

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Create Corrosion Loops / CircuitsAreas that have similar operating conditions, corrosion mechanisms, and materials

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Implement the IOW Program

• Recommend Standard, Critical, and Informational limits

• Select response times for each IOW limit based on IOW Risk Matrix

• Other Considerations

• Review IOW limits in conjunction with operating limits already established for safety (e.g. via HAZOP) and product quality before implementing

• Consider instrumentation currently in place and sampling points

• Client participation and commitment is essential

Safety Driven Performance Conference 2013

Example - IOW for Creep Damage in Heater Tubes

• Heater coils not susceptible to creep under normal conditions

• Flame instabilities can create locally hot areas

• Fouling can result in greatly reduced heat transfer

• Result – temperatures exceeding creep threshold temperature

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Creep Damage in 321 SS Heater Tubes

• Normal TMT T = 800 °F

• Lower limit for creep T = 1000 °F (API 579)

• Design temperatureT=1050 °F

• 2000 hour (12 week) creep life T = 1210 °F (API 579 Omega)

• Rapid deterioration T >1450 °F (API 530)

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Supplementing RBI - Risk Matrix for Assessing IOWs

• IOW Limit: Critical: 1210 ˚F

Standard: 1050 ˚F

• Response times: Critical IOW: 60 min

Standard IOW: 24 hr

Creep threshold: T = 1000 °F

Design temp: T=1050 °F

2000 yr. creep life: T=1210 °F

Rapid deterioration: T >1450 °F

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Another example of IOWs – much closer to the heart!

High Blood Pressure33.6% of US adults 20 years of age have hypertension.

The prevalence of hypertension is nearly equal between men and women.

Approximately 78% are aware of their condition, 68% are using antihypertensive medication, and only 44% of those treated had their hypertension controlled.

Controllable variablesObesity /Sedentary lifestyle

Tobacco / Alcohol abuse

Excess dietary sodium

Excessive alcohol intake

Stress

Cholesterol

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An “RBI Approach” + IOWs for Healthcare!

• Traditional RBI Approach• Assess individuals aged above 40• Focus on family and medical history• Treat symptoms with medications

• Incorporating IOWs • Yearly annual checkups for all age groups• Preventive care education – focus on monitoring

• Physical activity• Eating habits• Stress• Cholesterol levels• Smoking / Alcohol abuse

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IOW Limits - Other Considerations

• Is the limit practical – are operators constantly going to be responding to alarms?

• Balance between constantly reacting to alarms and having enough response time to prevent damage

• Consider which instruments or controls are already in place that could be used for monitoring

• Consider using information limits that do not generate operator alarms but capture and document a deviation

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Summary

• IOWs enhance traditional RBI programs by providing a proactive approach to managing reliability and risk

• Implementing an IOW program can provide better control and more confidence in managing the damage mechanisms

• Permits alternative feedstock/operations considerations by more clearly understanding the operating limits

• Can lead to improved facility safety and cost savings in terms of inspections and capital expenditures

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Thank you – Questions?