Key Topics. Steven T. Maher, PE CSP. Using HAZOP/LOPA to Create an Effective Mechanical Integrity Program. David J. Childs

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1 Steven T. Maher, PE CSP Using HAZOP/LOPA to Create an Effective Mechanical Integrity Program Steven T. Maher, PE CSP & 949/ 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 Risk Download Management Professionals Presentation & Handout Mechanical Engineering BS University of California Santa Barbara HAZOP/LOPA experience within multiple industries Supported development of effective Mechanical Integrity programs Paper & Webinars See Using HAZOP/LOPA to Create an Effective Mechanical Integrity Program Steven T. Maher, PE CSP & 949/ Risk Download Management Professionals Presentation & Handout 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 Saratoga News Photo MI Defined 1

2 Evolution of SMS Guidelines & Regulations to Performance (Goal) Based Standards PSM Elements Onshore Process Safety (USA) Offshore Safety Management Systems (USA) Offshore Safety Management Systems (UK) CA EP&R II MOC HWP EP PSI PHA PSM MI PSSR OP TRN CON 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) What is MI? 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). 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. Significant Events Involving Mechanical Integrity Failure Examples of Significant Events Flixborough 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 2

3 Examples of Significant Events Texas City 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 Why do a PHA? Hazard Analysis Tool Spectrum Checklist HAZID Each of these tools provides a different perspective & different insights. JSA LOPA Allows Risk Quantification & Graphical Scenario Development Bow-tie Using LOPA to Dig Further What-If/ Checklist API RP 14C Review CHAZOP ETA What-If FMECA HAZOP Risk-Graph FTA Less Effort Increased Effort, with Increased Insights Scenario-Based Analysis Objectives Tandem Advances in Protection System Design Architectures & Analysis Increasing Frequency Unacceptable Acceptable 4 Increasing Consequences RISK = PROBABILITY * CONSEQUENCES Probability = Likelihood of Occurrence Consequences = Effects of Occurrence For Engineered Systems: Risk = Σ F i * C i Single-Element Analog Devices Protection System Design Evolution Reliability Criteria & Design Architecture Specifications SIL-1 (10-2 PFD AVG < 10-1 ) Safety Integrity Levels Electronic Sensing & Sig. Processing SIL-2 (10-3 PFD AVG < 10-2 ) Voting Logic SIL-3 (10-4 PFD AVG < 10-3 ). 3

4 Control/Protection System Spectrum BPCS & SIS/HIPS Increasing Reliability & Larger SIL (SIS-Only, ANSI/ISA-S84.01 & IEC-61508/61511) Single-Element Analog Devices Decreased Cost Electronic Sensing & Sig. Processing Smart Sensors Separation of Control & Protection Redundancy High Pedigree Devices Diversity Increased Redundancy, Diversity, Pedigree Voting Logic End Device Feedback Loops BPCS = Basic Process Control System, SIS = Safety Instrumented System, HIPS = High Integrity Protection System LOPA Snapshot Risk Framework Risk(R) = Σ F i * C i Scenario Frequency Assessment as Absolute Value f ic = f ii * P EC ij * PFD ij * P CM ij Scenario Frequency Assessment as a Ratio TFSafety LOPA Ratio ( Safety) ICL PFD1 PFD2 PFD3... ECi CMi Where: ICL(f ii ) Initiating Cause Likelihood (Frequency) PFD Probability of Failure on Demand TF Target Frequency EC Enabling Condition CM Conditional Modifier MI Program Elements Feedback Requirements Pulling It Together Documentation Program Management Insp./Test. Maint./Repair Procedures Training MI Implementation Spectrum Computerized Maintenance Management System (CMMS) Memory of Maint. Mgr. Memory of Retiree Multi-Industry Application Complex Functions Process Industry Focus Key Functions Complementary Methodologies Post-It Notes Use of Maintenance Contractor Self-Standing Web-Based Written on Calendar Simple Scheduling Software Significant Training Requirements Intuitive Potential Effectiveness Challenges Increased Ability to Achieve Objectives 4

5 Complementary Methodologies DMR Implementation Spectrum API RP 581 Pressure Vessels and Piping Atmospheric Storage Tank Pressure Relief Devices Heat Exchanger Tube Bundles Effective Use of Standardized Maintenance Schedules Enhanced Contemporary Best Practices Less Effort Prioritized DMR Approach ipha Increased Effort, with Increased Insights MI-Centered Risk-Based Assessment Monitored Repairable Components Select Statistics to Optimize the MI Program Operating State Failed State Time Availability A( ) Time Monitored Repairable Components Unmonitored Repairable Components A( ) = Q( ) = A( ) + Q( ) = 1 Example For λ = 1E-6/hr, MTTR = 10 hr Q = 1E-5 Component Unavailability = Mean Time of Interest (τ) = Time Between Tests Mean Time of Unavailability = λτ 2 λ 2 Q = 5

6 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 Summary PHA/MI Complementary Elements Questions? 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 highpriority equipment Identification of over-application of SIS, where a BPCS component can provide adequate reliability with much lower recurring MI costs Steven T. Maher, PE CSP Steve.Maher@RMPCorp.com David.Childs@RMPCorp.com 877/