RBI RISK BASED INSPECTION Presented by: Mohammad Javad Ranjbar 5 May 2014
Outline Introduction to RBI •what is RBI •what are the key elements of RBI •how to implement an RBI program •how to sustain an RBI program
RBI Softwares • TWI - RISKWISE • ReliaSoft – RBI
What is RBI? Risk-based Inspection (RBI) is a methodology for identification of high-risk equipment by review of active/potential damage mechanisms and the suitability of mitigation methods RBI allows inspection/maintenance RBI systematical evaluated both the probability of failure and the associated consequence of failure. Risk is the combination of the probability of some event occurring during a time period of interest and the consequences,(generally negative) associated with the event. In mathematical terms, risk can be calculated by the equation: Risk = Probability × Consequence
RBI vs. Other Inspection Methods Fixed Interval • STANDARD Inspection • Service Interval
• TREND Analysis
• RISK Analysis
• Consequences not considered • Backward Looking
• Probability & Consequences • Proactive • Forward Looking
Objectives of RBI Increase Availability
1 CATASROPHIC FAILURE OF STEAMLINE (JAPAN 2004)
(reducing unplanned outages )
Improve Safety )Ensure Safe Operation)
Optimise Inspection Costs
RBI Benefits and Limitations • a) an overall reduction in risk for the facilities and
equipment assessed, • b) an acceptance/understanding of the current risk. RBI will not compensate: • c) inaccurate or missing information, • d) Design errors or faulty equipment installation, • e) External events (e.g. Collisions or falling object) • f) not effectively executing the plans, • g) Secondary effects from nearby units • h) lack of qualified personnel or teamwork,
Outcome of an RBI? • Appropriate Inspection Technique
• Types of damage expected
• Inspection Frequency
Where? • Hotspot locations
API 580 / API 581
DNV-RP-G101 (Offshore topsides)
Type of RBI Assessment Qualitative: Provides a broad-based risk assessment of
an operating unit or a part of an operating unit, required less detail information about the facility. In this assessment using engineering judgement and experience for the analysis of probability and consequences of failure. Quantitative: Provides risk values for each equipment item and pipe segment in a operating unit, required comprehensive detail information about the facility and equipment. In this assessment using logic models, likelihood and probability data to calculate the risk of failure. Semi-quantitative: Some were between either approach.
RBI planning process overview
1. Data Collection design and construction records/drawings: — P&IDs, process flow diagrams, material selection diagrams (MSDs), etc., — piping isometric drawings, — engineering specification sheets, — materials of construction records, — construction QA/QC records, — codes and standards used, — protective instrument systems, — leak detection and monitoring systems, — isolation systems, — inventory records — emergency depressurizing and relief systems, — safety systems, — fire-proofing and fire-fighting systems, — layout;
1. Data Collection inspection records — schedules and frequency, — amount and types of inspection, — repairs and alterations — inspection results
process data — fluid composition analysis including contaminants or trace components, — distributed control system data, — operating procedures, — start-up and shutdown procedures, — emergency procedures, — operating logs and process records,
1. Data Collection Off-site data and information — if consequence may affect off-site areas;
Failure data — generic failure frequency data — industry specific failure data, — plant and equipment specific failure data, — reliability and condition monitoring records, — leak data;
Site conditions — climate/weather records, — seismic activity records;
Equipment replacement costs — project cost reports, — industry databases;
1. Identification of Damage Mechanisms
2. Probability of Failure Probability Information 1. Number of units and type of plant: pressure vessel, tank, column, pipework, heat exchanger etc. 2. Plant function: distillation unit, cat cracker, storage etc 3. Plant processes: gas, hydrocarbon, steam etc, number of planned and unplanned interruptions per year 4. Process stability: rate stability from a) very stable no known upset conditions known to exist to b) loss of control is inherent in process 5. Plant maintenance history: repairs, modifications, quality of maintenance, painting & insulation maintenance
6. Material of construction: steel, stainless steel, cast steel, aluminium etc, any coatings 7. Damage mechanisms: what damage mechanisms are known to occur or have the potential to occur in the plant. eg stress corrosion, brittle failure, temper embrittlement, fatigue, localised or general corrosion, creep, others, 8. Inspection: dates, type (visual, thickness, MPI, UT etc) and extent of inspection, inspectability, inspection results, corrosion allowance. Effectiveness and management of the inspection programme.
2. Consequence of Failure Consequence Information 1. Fire: are external fire fighting resources required for the most serious event 2. Incident mitigation: which one: i) gas detection systems, ii) plant operated under inert atmosphere, iii) secure fire fighting system, iv) automatic or manual isolation systems v) blast walls around high pressure equipment, vi) drain, dump or blowdown systems that will deinventory plant vii) fire proofing of plant strct. and cables viii) available supply of fire water, hour? ix) foam system or water curtain
3. Chemical data: relates to the chemical’s tendency to ignite. What is the flash point of the material, rate its stability when unconfined. 4. Quantity: how much material could be released in a single event 5. Chemical state: what is the process temperature,what is the boiling point? 6. Commercial damage potential: what is the value of plant within a 30m radius, within 150m? 7. Toxicity: rate the toxicity from: a) no hazard to b) death or major injury on very short exposure 8. Population: number of people, on site and off site, within 500m of release point
3. Risk Analysis
RISK MATRIX: The LoF value is plotted on the vertical axis, and the CoF value is plotted on the horizontal axis, of the dimensionless 5×5
4. Inspection Planning When or before the risk target is reached, an inspection of the equipment is recommended based on a ranking of the component damage mechanisms that have the highest calculated damage factors.
An inspection program is the combination of NDE methods (i.e. visual, ultrasonic, radiographic etc.), frequency of inspection, and the location and coverage of an inspection. Inspection programs vary in their effectiveness for locating and sizing damage, and thus for determining damage rates.
4. Inspection Effectiveness Lack of coverage of an area subject to deterioration, Inherent limitations of some inspection methods to detect and quantify certain types of deterioration, Selection of inappropriate inspection methods and tools, Application of methods and tools by inadequately trained inspection personnel, Inadequate inspection procedures, The damage rate under some conditions (e.g. start-up, shutdown, or process upsets) may increase the likelihood or probability that failure may occur within a very short time. Inaccurate analysis of results leading to inaccurate trending of individual components, and Probability of detection of the applied NDE technique for a given component type, metallurgy, temperature and geometry .
5. Mitigation Reducing the POF, Primary source of consequence, magnitude of consequence: • Equipment Replacement and Repair • Evaluating Flaws for Fitness-For-Service
• Equipment Modification, Redesign, and Rerating • Emergency Isolation • Emergency Depressurizing/Deinventorying • Modify Process • Water Spray/Deluge • Blast-resistant Construction • spill detector • Fireproofing • …….;
6. Reassessment and Updating RBI Assessments Why Conduct an RBI Reassessment? • Damage Mechanisms and Inspection Activities • Process and Hardware Changes • RBI Assessment Premise Change • The Effect of Mitigation Strategies
When to Conduct an RBI Reassessment? • After Significant Changes • After a Set Time Period • After Implementation of Risk Mitigation Strategies • Before and After Maintenance Turnarounds
RBI Softwares RBI™
RB.Eye RB.QEye FAME+ Credo™
RISKWISE™ Risk Based Inspection / Risk Based Maintenance software
TWI Ltd is the sole owner of this software demonstration show and may change this demonstration without issuing notice. No person or entity may reproduce or transmit any part of the demonstration without written permission from TWI Ltd.
System Overview Introduction Ease of Use Access Controls Knowledge-base Options and Settings Fluid Properties Nameplate Information Inspection History Damage Mechanisms Risk Factors Risk Summary Risk Profile Record Data Tables Record Properties Risk Mitigation Risk Comparison Inspection Plans Management Reporting Contact TWI
RISKWISE™ has a friendly Microsoft® style graphical user interface )GUI), developed in Visual Basic using object-oriented design tools. Microsoft® Toolbar
Folder Tree Drag „n Drop Table Sorting
Intuitive Interface Graphical Navigation
RISKWISE™ is an API RP580 compliant riskbased inspection (RBI) planning tool for use with pressure equipment, pipelines, power boilers and storage tanks. The risk model is semiquantitative, so it can be easily learned and is convenient to use. RBI management systems are applied to:
Features Integration RISKWISE™ is a second generation client-server product, using the ODBC (Open DataBase Connectivity) protocol for SQL databases (eg FoxPro, SQL Server, Oracle and Access).
Improve the safety of critical plant Reduce the duration of inspection outages Extend the interval between major inspections Reduce direct inspection and maintenance costs
RISKWISE™ enables the system administrator to control user access, tailoring it to the specific needs of the inspection and maintenance organisation. This allows simple control and auditability of previous assessment records.
RISKWISE™ is designed to provide complete multi-lingual capability for rapid native language implementation.
Features Access Control Three main levels: Read-Only Proposal Write Item Write Access
Auditability The name of the assessor undertaking the RBI evaluations for each item of equipment is recorded, in compliance with best practice auditing principles.
Record Hierarchy Proposed inspection plans RBI assessment results which cannot be changed or deleted
RISKWISE™ stores equipment nameplate information in the Item Properties and Materials screens. This information can be easily integrated with asset information in other applications, via the in-built RISKWISE™ ‘Import Wizard’.
Features Item Properties Captures general information about the equipment including drawings, design and operating parameters.
Materials Captures information about the materials of construction components within equipment or pressure system.
RISKWISE™ contains an inspection knowledgebase covering non-destructive testing (NDT) methods and comprehensive descriptions of over 30 damage mechanisms (DM), including 20 corrosive species leading to general and localised corrosion and 10 species leading to stress corrosion cracking.
Features NDT The knowledge-base covers visual, magnetic, ultrasonic, eddy current, metallurgical, radiographic, thermographic, acoustic emission and other nonintrusive methods.
Damage Mechanisms The common mechanisms are categorised in terms of leading to „Metal loss‟, „Environmental‟ or „Metallurgical and mechanical‟ damage.
RISKWISE™ allows users complete freedom to undertake assessments in European, US Customary units or User-defined units. System administrators have the ability to define safety factors based on assessment consequence categories, for direct use in the derivation of equipment inspection intervals.
RISKWISE™ assesses consequence of failure generally in accordance with guidance provided in API BRD581 based on the fluid property classifications presented by National Fire Protection Association (NFPA).
Features Units Define system wide defaults for assessment, such as engineering units of measure.
Factors of Safety Modify configuration of safety factors, that are linked to the consequence categories, in the calculation of remaining life indicators for all damage mechanisms.
Features Chemical Factor A Flammability Factor is used by RISKWISE™, in combination with a Reactivity Factor, to derive a Chemical Factor, representing a fluid‟s inherent tendency to ignite.
Explosion and Fire RISKWISE™ assesses a State Factor and the Chemical Factor, in accordance with the procedure in publication API BRD581.
Toxicity RISKWISE™ employs the NFPA ranking of the probable severity of the effects of a fluid on exposure to personnel, in the event of a release and a fire.
RISKWISE™ captures all relevant historical inspection and maintenance history in the Inspection Methods screen for subsequent use in the identification of equipment damage mechanism prior to the risk assessment.
Features Inspection Methods Captures relevant historical information including coverage and findings, that will be regularly updated following future inspections.
Inspection Plans RISKWISE™ transfers historical findings as well as the proposed inspection activities, to the „Written Scheme of Examination‟.
RISKWISE™ captures the location of all active and potentially active damage mechanisms within each item of pressure equipment.
Features Checklist RISKWISE™ deals with damage mechanisms relevant to oil, gas and petrochemical process equipment, storage tanks, pipelines, and fossil fuel power boilers.
Remaining Life Indicators The estimated remaining life of each damage mechanism is assessed within RISKWISE™, to establish equipment inspection intervals.
RISKWISE™ assesses seven likelihood (probability) of failure factors and nine consequence of failure factors, for each item of equipment.
Features Time-based Risk Analysis RISKWISE™ assesses failure probability over three forward periods of time, for each active or potentially active damage mechanism.
Inspection Effectiveness RISKWISE™ assesses the effectiveness of the current inspection program for each damage mechanism separately.
RISKWISE™ presents the results of the risk analysis for each of the damage mechanisms, over the three forward time intervals, as well as the resulting remaining life indicator (RLI) which defines a safe inspection interval.
Features Risk Matrix RISKWISE™ plots each assessment point on an API RP580 five-by-five risk matrix for risk regions ranging from „Favourable‟ to „Critical‟.
Limiting Damage Mechanisms The lowest RLI out of all damage mechanisms equates to the maximum allowable inspection interval for the equipment.
RISKWISE™ provides a risk profile of all equipment within the facility for the identification of critical and non-critical equipment.
Features Summary The distribution of risk can be presented using a risk matrix, pie charts or bar charts as well as comparatively, ie for subsequent postassessment cost-benefit analysis.
RISKWISE™ simply identifies critical equipment as those items where the RLI is less than current inspection period, and non-critical equipment as those items where the RLI is greater than the current inspection period!
RISKWISE™ ensures that the individual authors of each equipment RBI assessment are fully traceable.
Table Sorting The results of the RBI assessment are presented in the RISKWISE™ data tables, which can be easily sorted using the „drag „n drop‟ column titles.
Auditability RISKWISE™ enables comprehensive tracking of assessment results and input assumptions, in accordance with the requirements of API RP580.
Record Notes RISKWISE™ includes a simple “catch-all” free text field for any other information relevant to the likelihood of consequence of failure of the equipment under consideration.
Action Grouping RISKWISE™ assigns the most frequently used risk mitigating actions to six groups, for ease of evaluation during the final inspection planning and optimisation phase of the RBI assessment.
Features Inspection Optimisation The process of risk comparison within RISKWISE™ enables users to systematically evaluate the effect of actions on the risk of failure, while considering the constraints. Total Savings = $1.1M B/C Ratio = 11:1 $900k
Production Cost Savings
RISKWISE™ allows the RBI assessor to evaluate the impact of the proposed actions or inspection changes on risk and the remaining life indicator (RLI).
RISKWISE™ presents RBI assessors with a risk action plan from which the most suitable risk mitigation options, for critical equipment, can be evaluated.
The final output of a RISKWISE™ assessment is an optimised inspection plan )‘Written Scheme of Examination’) which focuses on each damage mechanism.
RISKWISE™ provides a post-assessment analysis capability to evaluate the impact of actions on the risk distribution for all equipment.
Features Reporting RISKWISE™ presents a detailed report of the RBI assessment for use by field inspection engineers, or in other reports application as necessary.
Features Time Tracking RISKWISE™ enables the user to assess the value of RBI following successive major inspections and subsequent RBI updating, eg. between Revision 0 and Revision 1.
NEW Released Feature
RBI EXAMPLE Quantitative Assessment of a Boiler
Application Selection Chosse boilers as Oil,Gas and Process Plant Suite
Current Table A table of current revision records or a table of all proposal records can be displayed by navigating to these screens via the shortcut bar. These lengthy tables can be organised and sorted by dragging the column titles to the top of the screen, into any ordered display hierarchy:
Item Proposal Once you have specified the equipment class, (for example, specify that a particular pipe is a Hot Reheat Pipe), the list of expected damage mechanisms is shortened automatically to display the types of damage that might be expected.
Item Properties The entries on the unit properties screen determine the risk associated with various items in boilers.
Item Properties Enlarge the picture to see the detailes you have to enter.
Risk Factors All of the items on the Risk Factors screen will be readonly if the item properties, damage mechanisms and inspection methods screens are fully completed. If you need to change any of these values you will need to change back to manual mode
RISK Analysis The assessment points for each of the three risk analysis periods can be toggled on or hidden via the buttons on the toolbar. For example, if you wish to display the assessment points for the first analysis period (1AP) only, select the buttons to HIDE 2AP and HIDE 3AP. The risk plot will then only display 1AP ( ) assessments points.
Level 1 Assessment The level 1 assessment is a unit level assessment to assess a boiler as a whole. To switch to the level 1 view, click on the assessment level toggle at the top of the main screen. When switching to the level 1 assessment, the list of items now only shows units.
Home You can right-click on an existing unit to create a proposal, or create a new unit or proposal from the links on the home screen.
Unit Proposal Each unit has a set of properties associated with it in a similar way that other (level 2) components have an item properties list. The proposal record can be viewed by double clicking on it in the items list.
Unit Analysis The analysis screen shows the business consequence of the major components of the boiler failure.
THANK YOU FOR YOUR ATTENTION Your Questions Are Wellcomed …