12. Risk Management with Inspection Activities Flashcards
- Risk Management with Inspection Activities
- 1 Managing Risk by Reducing Uncertainty Through Inspection
- Impending failure of pressure equipment is not avoided by inspection activities unless
the inspection precipitates risk mitigation activities that change the POF.
- Risk Management with Inspection Activities
- 1 Managing Risk by Reducing Uncertainty Through Inspection
- The reduction in uncertainty and increase in predictability through inspection translates directly to a better
estimate of the probability of a failure and therefore a reduction in the calculated risk.
- Risk Management with Inspection Activities
- 1 Managing Risk by Reducing Uncertainty Through Inspection
- Some damage mechanisms are very difficult or impossible to monitor with just inspection activities (e.g. metallurgical deterioration that may result in brittle fracture, many forms of stress corrosion cracking, and even fatigue). In this case the
IOW and MOC complement the monitoring.
- Risk Management with Inspection Activities
- 1 Managing Risk by Reducing Uncertainty Through Inspection
- The quality of the inspection data and the analysis or interpretation will greatly affect
the level of risk mitigation.
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
- RBI will also identify whether consequence or POF or both is
driving risk.
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
- In the situations where risk is being driven by POF, there is usually potential for risk management through
inspection.
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
- Once an RBI assessment has been completed, the items with unacceptable risk to the owner-user shall be assessed for
potential risk management through inspection plans or other risk management strategies. Higher risk items should also be assessed for potential risk management actions.
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
- Depending on factors such as the remaining life of the equipment and type of damage mechanism, risk management through inspection may
have little or no effect.
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
- The most practical and cost-effective risk mitigation strategy can then be
developed for each item.
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
- Usually, inspection provides a major part of the
overall risk management strategy, but not always
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
Whether inspections will be effective or not will depend on
a) equipment
b) active and credible
c) rate of deterioration or
d) inspection methods, coverage, and
a) type;
b) damage mechanism(s);
c) susceptibility;
d) frequency;
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
Whether inspections will be effective or not will depend on
e) accessibility to expected
f) shutdown
g) amount of achievable reduction in
e) damage areas;
f) requirements;
g) POF (i.e. a reduction in POF of a low POF item is usually difficult to achieve through inspection).
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
Depending on factors such as the remaining life of the equipment and type of damage mechanism, risk management through inspection may have little or no effect. Examples of such cases are as follows:
a) corrosion rates well-established with
b) instantaneous failures related to operating conditions such
c) inspection technology that is not sufficient to detect or quantify
a) equipment nearing end of life;
b) as brittle fracture;
c) deterioration adequately;
- Risk Management with Inspection Activities
- 2 Identifying Risk Management Opportunities from RBI Results
Depending on factors such as the remaining life of the equipment and type of damage mechanism, risk management through inspection may have little or no effect. Examples of such cases are as follows:
d) too short a timeframe from the onset of deterioration to final failure for
e) event-driven
In cases such as these, an alternative form of mitigation may
d) periodic inspections to be effective (e.g.high-cycle fatigue cracking);
e) failures (circumstances that cannot be predicted).
be required.
- Risk Management with Inspection Activities
- 3 Establishing an Inspection Strategy Based on Risk Assessment
- The results of an RBI assessment are normally used as the basis for the development of
an overall inspection strategy for the group of items included.
- Risk Management with Inspection Activities
- 3 Establishing an Inspection Strategy Based on Risk Assessment
- The inspection strategy should be designed in conjunction with other mitigation plans so that all equipment items will have
resultant risks that are acceptable.
- Risk Management with Inspection Activities
- 3 Establishing an Inspection Strategy Based on Risk Assessment
- The inspection strategy shall be a documented, iterative process to assure that
inspection activities are continually focused on items with higher risk.
- Risk Management with Inspection Activities
- 3 Establishing an Inspection Strategy Based on Risk Assessment
Factors to consider when users develop their inspection strategy
a) risk criteria and
b) risk
c) equipment
d) number and results of
e) type and effectiveness of inspections;
f) equipment in similar service and
a) ranking;
b) drivers;
c) history;
d) inspections;
e) type and effectiveness of inspections;
f) remaining life.
- Risk Management with Inspection Activities
- 3 Establishing an Inspection Strategy Based on Risk Assessment
The level of risk reduction achieved by inspection will depend on the following:
a) mode of failure of
b) time interval between the onset of
c) detection capability of
d) scope and extent of
e) frequency of
a) the damage mechanism,
b) deterioration and failure (i.e. speed of deterioration),
c) examination technique,
d) inspection,
e) inspection.
- Risk Management with Inspection Activities
- 4 Managing Risk with Inspection Activities
Key inspection parameters and examples that can affect the future risk
a) Frequency of Inspection—Increasing it may serve to better define, identify, or monitor the
damage mechanism(s) and therefore better quantify the risk.
- Risk Management with Inspection Activities
- 4 Managing Risk with Inspection Activities
Key inspection parameters and examples that can affect the future risk
b) Coverage—Different zones or areas of inspection of an item or series of items can be modeled and evaluated to
determine the coverage that will produce an acceptable level of risk. For example:
1) a higher risk piping system may be a candidate for more extensive inspection, using one or more NDE techniques targeted to locating the identified damage mechanisms;
2) an assessment may reveal the need for focus on parts of a vessel where the highest risk may be located and focus on quantifying this risk rather than focusing on the rest of the vessel where there are perhaps only low risk deterioration processes occurring.
- Risk Management with Inspection Activities
- 4 Managing Risk with Inspection Activities
Key inspection parameters and examples that can affect the future risk
c) Tools and Techniques—The selection and usage of the appropriate inspection tools and techniques can be optimized to cost-effectively and
safely quantify the POF. However, the level of mitigation achieved can vary depending on the choice.
- Risk Management with Inspection Activities
- 4 Managing Risk with Inspection Activities
Key inspection parameters and examples that can affect the future risk
d) Procedures and Practices—If the inspection activities are executed effectively by well-trained and qualified inspectors, the expected risk management benefits should
be obtained.
- Risk Management with Inspection Activities
- 4 Managing Risk with Inspection Activities
Key inspection parameters and examples that can affect the future risk
e) Internal, On-stream, or External Inspection—Risk quantification by internal, on-stream, and external inspections should be assessed. Invasive inspections, in some cases, may cause
deterioration and increase the risk of the item. Examples where this may happen include the following:
1) moisture ingress to equipment leading to stress corrosion cracking or PASCC;
2) internal inspection of glass lined vessels;
3) removal of passivating films;
4) human errors in start-up (re-streaming);
5) increased risks associated with shutting down and starting up equipment.
- Risk Management with Inspection Activities
- 4 Managing Risk with Inspection Activities
Key inspection parameters and examples that can affect the future risk
The user can adjust these parameters to obtain the optimum inspection plan that
manages risk, is cost-effective, and is practical.
- Risk Management with Inspection Activities
- 5 Managing Inspection Costs with RBI
- Resources can be applied or shifted to those areas identified as a
higher risk or targeted based on the strategy selected.
- Risk Management with Inspection Activities
- 5 Managing Inspection Costs with RBI
- Reduction of inspection activities in those areas that have a lower risk or where the
inspection activity has little or no effect on the associated risks.
- Risk Management with Inspection Activities
- 5 Managing Inspection Costs with RBI
- Identifying items in the inspection plan that can be
inspected non-intrusively on-stream.
- Risk Management with Inspection Activities
- 5 Managing Inspection Costs with RBI
- The user should recognize that while reduction of inspection costs, increased equipment integrity and inspection cost optimization should
remain the focus.
- Risk Management with Inspection Activities
- 6 Assessing Inspection Results and Determining Corrective Action
- A documented mitigation action plan should be developed for
any equipment item requiring repair or replacement.
- Risk Management with Inspection Activities
- 6 Assessing Inspection Results and Determining Corrective Action
- . The action plan should describe the
extent of repair (or replacement), recommendations, the proposed repair method(s), appropriate QA/QC, and the date the plan should be completed.
- Risk Management with Inspection Activities
- 7 Achieving Lowest Life Cycle Costs with RBI
Examples can give a user ideas on how to lower life cycle costs through RBI with cost benefit assessments.
a) RBI should enhance the prediction of failures caused by damage mechanisms. This in turn should give the user confidence to continue to operate equipment safely, closer to the predicted failure date. By doing this,
the equipment cycle time should increase and life cycle costs decrease.
- Risk Management with Inspection Activities
- 7 Achieving Lowest Life Cycle Costs with RBI
Examples can give a user ideas on how to lower life cycle costs through RBI with cost benefit assessments.
b) RBI can be used to assess the effects of changing to a more aggressive fluid. A subsequent plan to upgrade construction material or replace specific items can then be developed. The construction material plan would consider the optimized run length safely attainable along with the appropriate inspection plan. This could equate to increased profits and lower life cycle costs through
reduced maintenance, optimized inspections, and increased unit/equipment uptime.
- Risk Management with Inspection Activities
- 7 Achieving Lowest Life Cycle Costs with RBI
Examples can give a user ideas on how to lower life cycle costs through RBI with cost benefit assessments.
c) Turnaround and maintenance costs also have an effect on the life cycle costs of an equipment item. By using the results of the RBI inspection plan to identify more accurately where to inspect and what repairs and replacements to expect, turnaround and maintenance work can be preplanned and,
in most cases, executed at a lower cost than if unplanned.
