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


Venue safety information

• Safety overview • Location of emergency exists


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


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!


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?


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


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


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


IOW Limits


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


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


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


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


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


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


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


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)


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


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


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


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


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


Thank you – Questions?

safety driven performance conference 2013 supplementing risk basked inspection programs with...

Documents

iow limits slide

review slide

process conditions

illustration slide

acceptable limits slide

iow implemen

operating life

increased risk