Senior engineer inspection David Burgess describes the experience of ABB Consulting of potential benefits and best practices for inspection (RBI) revalidation based on risk, which helps to further optimize inspection programs
Critics, such as pressure vessels, piping and storage tanks teams are often subject to risk-based inspection (RBI) to deliver optimal inspection policy and risk control. As the life of the team matures and businesses evolve, revalidation of existing RBI ensure they remain fit for purpose and evergreens.
What is RBI?
RBI is a methodical process to determine the optimal control system of industrial pressure equipment. The process involves a structured review of aspects teams to first identify possible mechanisms of injury / impairment assessment regarding the health, safety and environment (HSE) and business risks. A proper inspection policy can be determined to deliver a lower risk and optimized inspection regime. This often provides the additional benefits of reduced costs and to be more specific inspections to the risks identified resources.
In 1996, the American Petroleum Institute (API) published API 581 (Risk Based Inspection - Document Resource Base). This documents the methodology that has become adopted worldwide as the basis for the process of RBI.
WHAT IS THE RENEWAL RBI
RBI Reviews are generally performed for key critical equipment in any of the early stages of life, or at some point in their life cycle, often driven by integrity and / or budget considerations?
Revalidation is a process of reviewing existing RBI to check the assumptions made initial review are still valid and has not changed anything that could negatively affect the risk. RBI is based on performance, design, inspection and maintenance of data available at the time of the review. More data are added throughout the lifecycle of equipment that can confirm or contradict the assumptions made original RBI.
Due to the nature of the risk assessment, a conservative view is often taken during initial RBI reviews, particularly those made during the early life of the equipment where limited operating history and inspection. As a result, initial inspection requirements often can be set on the cautious side until more history and trust is earned.
Revalidation helps further optimize inspection programs and ensure that risks are properly managed either by increased inspection requirements where history shows evidence of deterioration and / or aging, or reduce inspection where there is little or no evidence of impairment. Frequency of inspection is reviewed and potential for non-invasive inspection is also considered where appropriate. This renewal process helps keep evergreen RBI and fit for purpose in a regulatory environment and increasingly challenging business.
WHEN SHOULD BE COMPLETED?
Ideally RBI should be reviewed after each major inspection to record the results and verify that the initial assumptions are still valid. If there have been unexpected failures or repairs, then RBI revalidation can also be a valuable process in establishing the root cause to prevent reoccurrence. As the plant begins to enter its aging phase lifecycle, RBI ensure revalidation frequency of inspection is safely within the allocations corrosion rate and possible restrictions limited life that may be relevant, such as creep and fatigue.
Who should be involved?
Validation RBI should preferably be carried out by an independent person with experience in inspection and integrity to give a balanced view. Also have to be consulted when needed during the review of Representatives operations, maintenance, inspection and any support from specialists such as engineers of materials / corrosion and functional.
Revalidation process RBI
The procedure for carrying out RBI revalidation begins with a review of the operation history to verify that there are no significant changes in key aspects such as process fluid composition, temperature and pressure constant for cyclic operation, decontamination / Implementation Methods up, etc. Any corrosion control / monitoring program can also be reviewed to ensure that it is being completed as required and that the results are within expectations.
Inspection results are checked against original assumptions RBI. Make unexpected deterioration mechanisms that are not counted? Are the rates of deterioration and location (s) as expected? Corrosion rates between inspections should not exceed 50 percent margin of corrosion. Or is the corrosion rate much less than expected?
The original RBI may have made assumptions about the maintenance program when deciding on the probability of failure scenarios, for example, the fully functional and properly maintained cathodic protection, vibration monitoring of rotating equipment occurs adjacent to detect potential vibration imparted. These must be audited to confirm that you are established in the RBI. Maintenance history may include faults or repairs not covered by the inspection or any maintenance carried out as a result of "one-time" process excursions.
HSE and commercial consequences may change over time. Changes in occupancy levels of staff, new equipment installed in the vicinity contains toxic / flammable, modifies the state of the single stream, reducing the capacity available on site. All these are examples that may affect the overall risk and justify changing the inspection regime.
RBI is often used to establish an appropriate inspection program before the team enters service. If a new application (process or materials), the original RBI may have recommended inspections "one-off" to confirm the possibility of very low probability deterioration mechanisms occur. This requirement may be removed inspection program if no problems are found during inspections. The results of RBI revalidation may be either, the inspection program RBI and remain appropriate, minor changes are required in the inspection program and RBI, or RBI is no longer valid and needs a major overhaul to produce a new program inspection.
RBI LIFE CYCLE AND EQUIPMENT
The impairment of tangible assets due to age-related mechanisms such as corrosion, erosion and fatigue is a key issue for the industry. The Health and Safety Executive have recognized the integrity of asset management and the issue of aging of the plant as key issues to address in their inspection programs. (HSE Research Report RR823, Aging Plant Manager).
Later life may be defined as after 80 percent of the design life, which may be based on the corrosion rate / grant, the number of operating cycles or creep life. As additional mechanisms of aging become relevant in later life a thorough review of the RBI is recommended. The combination Review RBI with a fitness for duty evaluation is often used to determine whether the useful life can be extended (see Figure 1)
RENEWAL RBI, STRATEGIES NII
RBI may determine that a strategy of non-invasive inspection (NII) is appropriate. NII suitability for decision depends on the operating conditions well understood and controlled so that any degradation can be properly identified and monitored through a noninvasive strategy inspection and fault the consequences are not significantly high. For these cases, it is particularly important that RBI revalidation occurs and is essential when the team enters its later stage of life.
CASE STUDY
ABB RBI undertook studies with a client of oil and gas onshore and offshore facilities, the project includes more than 1,000 items including vessels, storage tanks and 15 kilometers of piping systems. The study team included operations, processes, maintenance and inspection representatives and used a qualitative approach RBI. Following this examination was carried out RBI revalidation to check the assumptions made during the study and the results of specific tests to provide evidence of deterioration mechanisms that were thought to be unlikely. A key focus was to identify whether the review could be conducted by NII. After the initial RBI over 50 percent of the vessels were transferred to NII and revalidation RBI verified this approach.
Figure 2 shows the average interval between examinations and this change to the media after the initial RBI RBI and after revalidation. The client saved over 2.2 billion pounds ($ 3.42 million) in inspection costs, but the great advantage is the reduction in downtime of equipment and lower risk profile due to the understanding of specific degradation mechanisms.
ADDITIONAL BENEFITS RBI RENEWAL
Independent RBI revalidation can also verify that the defined inspection program is suitable for detecting deterioration mechanisms mentioned and is being completed as specified by the RBI.
Critics, such as pressure vessels, piping and storage tanks teams are often subject to risk-based inspection (RBI) to deliver optimal inspection policy and risk control. As the life of the team matures and businesses evolve, revalidation of existing RBI ensure they remain fit for purpose and evergreens.
What is RBI?
RBI is a methodical process to determine the optimal control system of industrial pressure equipment. The process involves a structured review of aspects teams to first identify possible mechanisms of injury / impairment assessment regarding the health, safety and environment (HSE) and business risks. A proper inspection policy can be determined to deliver a lower risk and optimized inspection regime. This often provides the additional benefits of reduced costs and to be more specific inspections to the risks identified resources.
In 1996, the American Petroleum Institute (API) published API 581 (Risk Based Inspection - Document Resource Base). This documents the methodology that has become adopted worldwide as the basis for the process of RBI.
WHAT IS THE RENEWAL RBI
RBI Reviews are generally performed for key critical equipment in any of the early stages of life, or at some point in their life cycle, often driven by integrity and / or budget considerations?
Revalidation is a process of reviewing existing RBI to check the assumptions made initial review are still valid and has not changed anything that could negatively affect the risk. RBI is based on performance, design, inspection and maintenance of data available at the time of the review. More data are added throughout the lifecycle of equipment that can confirm or contradict the assumptions made original RBI.
Due to the nature of the risk assessment, a conservative view is often taken during initial RBI reviews, particularly those made during the early life of the equipment where limited operating history and inspection. As a result, initial inspection requirements often can be set on the cautious side until more history and trust is earned.
Revalidation helps further optimize inspection programs and ensure that risks are properly managed either by increased inspection requirements where history shows evidence of deterioration and / or aging, or reduce inspection where there is little or no evidence of impairment. Frequency of inspection is reviewed and potential for non-invasive inspection is also considered where appropriate. This renewal process helps keep evergreen RBI and fit for purpose in a regulatory environment and increasingly challenging business.
WHEN SHOULD BE COMPLETED?
Ideally RBI should be reviewed after each major inspection to record the results and verify that the initial assumptions are still valid. If there have been unexpected failures or repairs, then RBI revalidation can also be a valuable process in establishing the root cause to prevent reoccurrence. As the plant begins to enter its aging phase lifecycle, RBI ensure revalidation frequency of inspection is safely within the allocations corrosion rate and possible restrictions limited life that may be relevant, such as creep and fatigue.
Who should be involved?
Validation RBI should preferably be carried out by an independent person with experience in inspection and integrity to give a balanced view. Also have to be consulted when needed during the review of Representatives operations, maintenance, inspection and any support from specialists such as engineers of materials / corrosion and functional.
Revalidation process RBI
The procedure for carrying out RBI revalidation begins with a review of the operation history to verify that there are no significant changes in key aspects such as process fluid composition, temperature and pressure constant for cyclic operation, decontamination / Implementation Methods up, etc. Any corrosion control / monitoring program can also be reviewed to ensure that it is being completed as required and that the results are within expectations.
Inspection results are checked against original assumptions RBI. Make unexpected deterioration mechanisms that are not counted? Are the rates of deterioration and location (s) as expected? Corrosion rates between inspections should not exceed 50 percent margin of corrosion. Or is the corrosion rate much less than expected?
The original RBI may have made assumptions about the maintenance program when deciding on the probability of failure scenarios, for example, the fully functional and properly maintained cathodic protection, vibration monitoring of rotating equipment occurs adjacent to detect potential vibration imparted. These must be audited to confirm that you are established in the RBI. Maintenance history may include faults or repairs not covered by the inspection or any maintenance carried out as a result of "one-time" process excursions.
HSE and commercial consequences may change over time. Changes in occupancy levels of staff, new equipment installed in the vicinity contains toxic / flammable, modifies the state of the single stream, reducing the capacity available on site. All these are examples that may affect the overall risk and justify changing the inspection regime.
RBI is often used to establish an appropriate inspection program before the team enters service. If a new application (process or materials), the original RBI may have recommended inspections "one-off" to confirm the possibility of very low probability deterioration mechanisms occur. This requirement may be removed inspection program if no problems are found during inspections. The results of RBI revalidation may be either, the inspection program RBI and remain appropriate, minor changes are required in the inspection program and RBI, or RBI is no longer valid and needs a major overhaul to produce a new program inspection.
RBI LIFE CYCLE AND EQUIPMENT
The impairment of tangible assets due to age-related mechanisms such as corrosion, erosion and fatigue is a key issue for the industry. The Health and Safety Executive have recognized the integrity of asset management and the issue of aging of the plant as key issues to address in their inspection programs. (HSE Research Report RR823, Aging Plant Manager).
Later life may be defined as after 80 percent of the design life, which may be based on the corrosion rate / grant, the number of operating cycles or creep life. As additional mechanisms of aging become relevant in later life a thorough review of the RBI is recommended. The combination Review RBI with a fitness for duty evaluation is often used to determine whether the useful life can be extended (see Figure 1)
RENEWAL RBI, STRATEGIES NII
RBI may determine that a strategy of non-invasive inspection (NII) is appropriate. NII suitability for decision depends on the operating conditions well understood and controlled so that any degradation can be properly identified and monitored through a noninvasive strategy inspection and fault the consequences are not significantly high. For these cases, it is particularly important that RBI revalidation occurs and is essential when the team enters its later stage of life.
CASE STUDY
ABB RBI undertook studies with a client of oil and gas onshore and offshore facilities, the project includes more than 1,000 items including vessels, storage tanks and 15 kilometers of piping systems. The study team included operations, processes, maintenance and inspection representatives and used a qualitative approach RBI. Following this examination was carried out RBI revalidation to check the assumptions made during the study and the results of specific tests to provide evidence of deterioration mechanisms that were thought to be unlikely. A key focus was to identify whether the review could be conducted by NII. After the initial RBI over 50 percent of the vessels were transferred to NII and revalidation RBI verified this approach.
Figure 2 shows the average interval between examinations and this change to the media after the initial RBI RBI and after revalidation. The client saved over 2.2 billion pounds ($ 3.42 million) in inspection costs, but the great advantage is the reduction in downtime of equipment and lower risk profile due to the understanding of specific degradation mechanisms.
ADDITIONAL BENEFITS RBI RENEWAL
Independent RBI revalidation can also verify that the defined inspection program is suitable for detecting deterioration mechanisms mentioned and is being completed as specified by the RBI.
