2 Venue safety information Safety overviewLocation of emergency exists
3 Overview Review plant reliability goals IOW and RBI basics Benefits of an IOW programSupplementing RBI program with IOWsExamples in refinery applicationQ & A
4 Plant Reliability Goals Ensure equipment performs it’s required functions for a specific time periodMaximize equipment availabilityOptimize maintenanceReduce risk and potential for leak/ruptureProvide early recognition of equipment risks due to process deviationsIn short - No surprises!
5 Risk Based Inspection - RBI Uses past operating conditions and inspection data to make future predictionsCaptures risk at a snap shot in timeWhat happens when process conditions change?
6 Existing Industry Standards Importance of monitoring operating conditionsAPI 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 IOWsSecond Draft in review
7 Process & Operational Impact Processes are not always stableFeedstock variationsUpsetsWhen changes to operating conditions affect key process variablesNew damage mechanisms may be introducedCorrosion rates may accelerateThese excursions are typically unaccounted and their impact not considered
8 IOW ConceptsIOWs are allowable operating limits for a process variableEstablished to manage corrosion and other damage mechanismsDifferent from SOL, Alarms for Pressure integrity (MAWP etc.)Requires a response within established timeframes if limit is exceededFailure to bring the operating condition within the IOW limit within established timeframe will result in damage to the equipment outside of acceptable limits
10 Remaining Life (years) An IllustrationTemperatureBreached IOW level for 3 monthsIOW – Critical High / SOLIOW – Standard HighExpected Risk ProfileRiskAcceptable Risk LevelRemaining Life (years)ActualRemainingLifeExpected Remaining LifeEarly failure41025Time (years)
11 Benefits of an IOW Program Proactive approach to managing reliability and riskReal time notification of an increased riskAllows for timely intervention when process conditions changeExtends operating life of an assetEnhances safetyCost savings - reduced inspection costs and capital expenditures
12 IOW Implementation Team Multidisciplinary team of SME’sCorrosion Engineer / specialistProcess EngineerReliability Engineer / RBI specialistsOperations personnelPlant inspectorOthers – chemical treatment vendor, license technology specialists
13 Steps in Establishing an IOW Program Collect and Review DataCollect and review dataCreate corrosion loops or circuitsCorrosion studyDamage mechanism reviewEstablish IOW LimitsImplement IOW programIdentify actions and responsibilitiesProcess historian and Alarm configurationCreate Corrosion Circuits / LoopsCorrosion Study and IOW LimitsImplement IOW Program
14 Create Corrosion Loops / Circuits Areas that have similar operating conditions, corrosion mechanisms, and materials
15 Implement the IOW Program Recommend Standard, Critical, and Informational limitsSelect response times for each IOW limit based on IOW Risk MatrixOther ConsiderationsReview IOW limits in conjunction with operating limits already established for safety (e.g. via HAZOP) and product quality before implementingConsider instrumentation currently in place and sampling pointsClient participation and commitment is essential
16 Example - IOW for Creep Damage in Heater Tubes Heater coils not susceptible to creep under normal conditionsFlame instabilities can create locally hot areasFouling can result in greatly reduced heat transferResult – temperatures exceeding creep threshold temperature
17 Creep Damage in 321 SS Heater Tubes Normal TMT T = 800 °FLower limit for creep T = 1000 °F (API 579)Design temperature T=1050 °F2000 hour (12 week) creep life T = 1210 °F (API 579 Omega)Rapid deterioration T >1450 °F (API 530)
19 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 lifestyleTobacco / Alcohol abuseExcess dietary sodiumExcessive alcohol intakeStressCholesterol
20 An “RBI Approach” + IOWs for Healthcare! Traditional RBI ApproachAssess individuals aged above 40Focus on family and medical historyTreat symptoms with medicationsIncorporating IOWsYearly annual checkups for all age groupsPreventive care education – focus on monitoringPhysical activityEating habitsStressCholesterol levelsSmoking / Alcohol abuse
21 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 damageConsider which instruments or controls are already in place that could be used for monitoringConsider using information limits that do not generate operator alarms but capture and document a deviation
22 SummaryIOWs enhance traditional RBI programs by providing a proactive approach to managing reliability and riskImplementing an IOW program can provide better control and more confidence in managing the damage mechanismsPermits alternative feedstock/operations considerations by more clearly understanding the operating limitsCan lead to improved facility safety and cost savings in terms of inspections and capital expenditures
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