14. Reassessment and Updating RBI Assessments

Question 1

14 Reassessment and Updating RBI Assessments

14.1 RBI Reassessments

Highlights

Answer 1

1. RBI assessment shall be updated.
2. The most recent inspection, process, and maintenance information is included.
3. All these updates can all have significant effects on risk, and therefore the inspection plan, and can trigger the need to perform a reassessment.

Question 2

14 Reassessment and Updating RBI Assessments

14. 2 Why Conduct an RBI Reassessment?
15. 2.1 General

Highlights

Answer 2

1. It is important that the facility have an effective work process that identifies when a reassessment is necessary.

Question 3

14 Reassessment and Updating RBI Assessments

14. 2 Why Conduct an RBI Reassessment?
15. 2.2 Damage Mechanisms and Inspection Activities

Highlights

Answer 3

1. Typically, the RBI assessment will project deterioration at a constant rate, but in reality, the deterioration rate may vary over time.
2. When intermittent conditions occur, an RBI reassessment may be appropriate. It is important to review the operating histories over the past run, including IOW exceedances and trends
3. Inpections results shall be reviewed to determine if an RBI reassessment is necessary.

Question 4

14 Reassessment and Updating RBI Assessments

14. 2 Why Conduct an RBI Reassessment?
15. 2.3 Process and Hardware Changes

Highlights

Answer 4

1. This Process and Hardware Changes frequently can significantly alter the risks and dictate the need for a reassessment.
2. Process changes, in particular, have been linked to equipment failure from rapid or unexpected corrosion or cracking. Examples include: chloride stress corrosion cracking of stainless steel, wet H2S cracking of carbon steel, and accelerated corrosion at points of salt deposition or at dew points and sour water corrosion.
3. Hardware changes can also have an effect on risk. For example:
   a) POF can be affected by changes in the design of internals in a vessel or size and shape of piping systems that accelerate velocity related corrosion effects;
   b) COF can be affected by the relocation of a vessel to an area near an ignition source;
   c) process conditions can be changed by hardware modifications, additions, deletions, or bypassing.

Question 5

14 Reassessment and Updating RBI Assessments

14. 2 Why Conduct an RBI Reassessment?
15. 2.4 RBI Assessment Premise Change

Highlights

Answer 5

The premises for the RBI assessment could change and have a significant impact on the risk results. Some of the
possible changes could be as follows:
a) increase or decrease in population density in the process unit;
b) change in construction material and repair/replacement costs;
c) change in product values;
d) revisions in safety and environmental laws and regulations;
e) revisions in the users RMP (such as changes in risk criteria);
f) change in feed amount or composition;
g) changes in operating conditions;
h) change in unit operating lengths between maintenance turnarounds;
i) changes in inspection codes/standards.

Question 6

14 Reassessment and Updating RBI Assessments

14. 2 Why Conduct an RBI Reassessment?
15. 2.5 The Effect of Mitigation Strategies

Highlights

Answer 6

1. Once a mitigation strategy is implemented, a reassessment of the risk may be performed to update the RBI program with the new current risks.

Question 7

14 Reassessment and Updating RBI Assessments

14. 3 When to Conduct an RBI Reassessment
15. 3.1 After Significant Changes

Highlights

Answer 7

1. After significant changes in process conditions, phisical conditions, damage mechanisms/rates/severities, or RBI premises.

Question 8

14 Reassessment and Updating RBI Assessments

14. 3 When to Conduct an RBI Reassessment
15. 3.2 After a Set Time Period

Highlights

Answer 8

1. Users should set default maximum time periods for reassessments.
2. The governing inspection codes (such as API 510, API 570, and API 653) and jurisdictional regulations, if any, shall be reviewed in this context.

Question 9

14 Reassessment and Updating RBI Assessments

14. 3 When to Conduct an RBI Reassessment
15. 3.3 After Implementation of Risk Mitigation Strategies

Highlights

Answer 9

1. Once a mitigation strategy is implemented, it is prudent to determine how effective the strategy was in reducing the risk to an acceptable level.
2. This should be reflected in a reassessment of the risk and appropriate update in the documentation.

Question 10

14 Reassessment and Updating RBI Assessments

14. 3 When to Conduct an RBI Reassessment
15. 3.4 Before and After Maintenance Turnarounds

Highlights

Answer 10

1. This can become a first step in planning the turnaround to ensure that the work effort is focused on:
   - the higher risk equipment items
   - on issues that might affect the ability to achieve the premised operating run time in a safe, economic, and environmentally sound manner.
2. It is important update an assessment soon after the turnaround to reflect the new risk levels.