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Risk Management Professionals
Using HAZOP/LOPA to Create an Effective
Mechanical Integrity Program
Steven T. Maher, PE CSP & David J. ChildsRisk Management Professionals
949/282-0123www.RMPCorp.com
Download Presentation & Handout – www.SEMS1.com/GCPS/2017.htm
Risk Management Professionals
Steven T. Maher, PE CSPRisk Management Professionals
• 37-Year Engineer – 33 in Process Safety Consulting Specializing in Hazard Analysis and QRA
• Mechanical Engineering– BS – Duke University– MS – Carnegie-Mellon University
• Professional Engineer – Mechanical & Chemical Engineering• CCPS Technical Steering Committee – mid-1980s• Past-President Southern CA Society for Risk Analysis• Landmark Efforts
– Platform Safety Shutdown System Effectiveness Study– Torrance Refinery Safety Advisor for MHF Conversion
• Paper & Book Publications – See www.RMPCorp.com
Risk Management Professionals
David J. ChildsRisk Management Professionals
• Mechanical Engineering– BS – University of California Santa Barbara
• HAZOP/LOPA experience within multiple industries• Supported development of effective Mechanical
Integrity programs• Paper & Webinars– See www.RMPCorp.com
Risk Management Professionals
Using HAZOP/LOPA to Create an Effective
Mechanical Integrity Program
Steven T. Maher, PE CSP & David J. ChildsRisk Management Professionals
949/282-0123www.RMPCorp.com
Download Presentation & Handout – www.SEMS1.com/GCPS/2017.htm
Risk Management Professionals
Key Topics
• MI Defined• Significant Events Involving MI Faliure• Why do a PHA?• Using LOPA to Dig Further• Pulling It Together• Complementary Methodologies• Select Statistics to Optimize the MI Program• Summary• Questions
Risk Management Professionals
MI Defined
Saratoga News Photo
Evolution of SMS Guidelines & Regulations to Performance (Goal) – Based Standards
Onshore Process Safety (USA)
Offshore Safety Management Systems (USA)
Offshore Safety Management Systems (UK)
PSM Elements
PSM
EPPSI
PHA
OP
TRN
CON
PSSRMI
HWP
MOC
II
EP&R
CA
• Employee Participation• Process Safety Information• Process Hazard Analysis• Operating Procedures• Training• Contractors• Pre-Startup Safety Review• Mechanical Integrity• Hot Work Permit• Management of Change• Incident Investigation• Emergency Planning &
Response• Compliance Audits (CA-IIPP)
Risk Management Professionals
What is MI?
• Key Premise (from CMA Process Safety Code of Management Practices) – “Process equipment that is properly designed, fabricated, installed and operated should provide reliable service – if it is adequately inspected, tested and maintained over the life of the facility.”
• MI Definition – Maintaining the design function of structures and equipment
• MI is required by SEMS, RMP, PSM, & State ARP.• A less-rigorous requirement for simpler RMP and
State ARP Programs is called Preventive Maintenance (PM).
Risk Management Professionals
What is MI?
• Preventive Maintenance is a key component of Mechanical Integrity … also Inspection, Testing, & Repair.
• MI can apply to any type of the device or structure; however, for regulated facilities; MI may apply to:– Tanks, Pressure Vessels, and Piping– BOP and Pressure Relief Systems– Emergency Shutdown Systems– Rotating Equipment– Controls (including monitoring devices & sensors, alarms, & interlocks)
(e.g., Gas Detector function & calibration)– Any Device That Might be Listed as a Safeguard in a Hazards Analysis
• MI can be used for reliability; however, the focus of PSM, RMP, & SEMS is safety & environmental.
Risk Management Professionals
Significant Events Involving Mechanical Integrity Failure
Risk Management Professionals
Examples of Significant Events Flixborough - 1974
• Cyclohexane vapor cloud generated– Cracked reactor
vessel– Temporary bypass
fabricated in plant– Bypass failed– Significant
explosion– 28 fatalities & 36
injuries
June 2004 – CCPS Process Safety Beacon
Risk Management Professionals ©
Examples of Significant EventsTexas City - 2005
• During startup of ISOM Unit, overflow of Distillation Tower and Blowdown Drum– Valve left closed on liquid to
drain from bottom of tower (procedural step omitted)
– Failure of high and high-high liquid level alarm
• No documented test methods
– Level transmitter indicated that liquid level was falling at ~9 feet (actual level – 158 feet)
– Overflow of flammables ignited by idling truck resulting in 15 deaths and 180 injuries
– Siting Issues
September 2004 – CCPS Process Safety Beacon
September 2009 – CCPS Process Safety Beacon
Risk Management Professionals
Why do a PHA?
Risk Management ProfessionalsRisk Management Professionals
Hazard Analysis Tool Spectrum
Each of these tools provides a different perspective & different insights. Allows Risk
Quantification & Graphical Scenario
Development
What-If HAZOP
ETA
Risk-Graph FTA
Checklist
FMECA
Less Effort Increased Effort, with Increased Insights
What-If/Checklist
API RP 14CReview
HAZID Bow-tieJSA
CHAZOP
LOPA
Risk Management Professionals
Using LOPA to Dig Further
Risk Management ProfessionalsRisk Management Professionals
Scenario-Based Analysis Objectives
• RISK = PROBABILITY * CONSEQUENCES– Probability =
Likelihood of Occurrence
– Consequences = Effects of Occurrence
• For Engineered Systems:– Risk = Σ Fi * Ci
Increasing Consequences
Incr
easi
ng F
requ
ency
2
3
4
5
1Acceptable
Unacceptable
Risk Management Professionals
Tandem Advances in Protection System Design Architectures & Analysis
Protection System Design Evolution
Reliability Criteria & Design Architecture Specifications
Safety Integrity Levels
.
SIL-1(10-2 ≤ PFDAVG < 10-1)
SIL-2(10-3 ≤ PFDAVG < 10-2)
SIL-3(10-4 ≤ PFDAVG < 10-3)
Voting LogicSingle-ElementAnalog Devices
ElectronicSensing &
Sig. Processing
Risk Management ProfessionalsRisk Management Professionals
Control/Protection System Spectrum – BPCS & SIS/HIPS
Redundancy
Diversity
End DeviceFeedback
Loops
Single-ElementAnalog Devices
ElectronicSensing &
Sig. Processing
Decreased Cost Increased Redundancy, Diversity, Pedigree
Separation ofControl &Protection
SmartSensors
High PedigreeDevices
Increasing Reliability & Larger SIL (SIS-Only, ANSI/ISA-S84.01 & IEC-61508/61511)
BPCS = Basic Process Control System, SIS = Safety Instrumented System,HIPS = High Integrity Protection System
Voting Logic
Risk Management Professionals
LOPA Snapshot
• Risk Framework– Risk(R) = Σ Fi * Ci
• Scenario Frequency Assessment as Absolute Value– fi
C = fiI * ∏Pij
EC * ∏PFDij * ∏PijCM
• Scenario Frequency Assessment as a Ratio
• Where:– ICL(fi
I) – Initiating Cause Likelihood (Frequency)– PFD – Probability of Failure on Demand– TF – Target Frequency– EC – Enabling Condition– CM – Conditional Modifier
CMiECiPFDPFDPFDICLTF
SafetyRatioLOPA Safety
...)(
321
Risk Management Professionals
Pulling It Together
Risk Management Professionals
MI Program Elements
Require-ments
ProgramManagement
Procedures
Training
Insp./Test.Maint./Repair
Documentation
Feedback
Risk Management Professionals
MI Implementation SpectrumComputerized Maintenance
Management System (CMMS)
ComplexFunctions
ProcessIndustryFocus
Potential Effectiveness Challenges Increased Ability to Achieve Objectives
Memory ofMaint. Mgr.
Multi-IndustryApplication
Self-Standing
SignificantTraining
Requirements
SimpleScheduling
Software
Use of MaintenanceContractor
Key Functions
Web-Based
Intuitive
Memory ofRetiree
Post-It Notes
Written onCalendar
Risk Management Professionals
Complementary Methodologies
Risk Management ProfessionalsRisk Management Professionals
Complementary Methodologies
• API RP 581– Pressure Vessels and Piping– Atmospheric Storage Tank– Pressure Relief Devices– Heat Exchanger Tube Bundles
• Effective Use of Standardized Maintenance Schedules
Risk Management ProfessionalsRisk Management Professionals
DMR Implementation Spectrum
EnhancedContemporary
BestPractices
PrioritizedDMR
ApproachiPHA
Less Effort Increased Effort, with Increased Insights
MI-CenteredRisk-BasedAssessment
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Select Statistics to Optimize the MI Program
Risk Management ProfessionalsRisk Management Professionals
Monitored Repairable Components
Time
Time
A(∞)
Operating State
Failed State
Availability
1.0
0.5
Risk Management ProfessionalsRisk Management Professionals
Monitored Repairable Components
• A(∞) =
• Q(∞) = • A(∞) + Q(∞) = 1• Example
– For λ = 1E-6/hr, MTTR = 10 hr– Q = 1E-5
Risk Management ProfessionalsRisk Management Professionals
Unmonitored Repairable Components
• Component Unavailability =
• Mean Time of Interest ( ) = Time Between Tests• Mean Time of Unavailability =
2
• Q =
Risk Management ProfessionalsRisk Management Professionals
Dynamics of Plant MI
• Issues Can Materialize– Variance of inspection/testing intervals– Variance of inspection/testing methods– Impact of maintenance outage time on equipment
reliability– Repair prioritization and allowable outage time– Feedback of reliability observations back into the
MI Program• Optimize MI Implementation By Understanding
Statistics Concepts
Risk Management Professionals
Summary
Risk Management ProfessionalsRisk Management Professionals
PHA/MI – Complementary Elements
• Using HAZOP/LOPA to Enhance the Effectiveness of the MI Program– Ensuring that high-priority equipment gets the
attention needed– Optimizing inspection, testing, and preventive
maintenance frequencies– Identification of low-priority equipment, so that
Plant Maintenance Department can focus on high-priority equipment
– Identification of over-application of SIS, where a BPCS component can provide adequate reliability with much lower recurring MI costs
Risk Management Professionals
Questions?
Steven T. Maher, PE [email protected]
David J. [email protected]
877/532-0806www.RMPCorp.com
Risk Management Professionals