What is Risk-Based Inspection?
Risk-Based Inspection (RBI) is a systematic methodology for prioritizing and planning inspections based on risk rather than fixed time intervals. It focuses inspection resources on equipment with the highest risk of failure.
The fundamental principle: Risk = Probability of Failure × Consequence of Failure
Industry Standard
Why Move from Time-Based to Risk-Based?
Problems with Time-Based Inspection
- Inspects low-risk equipment too frequently, wasting resources
- May miss high-risk equipment that needs more attention
- Doesn't account for actual operating conditions
- Results in unnecessary shutdowns
Benefits of RBI
20-50% reduction
25-40% decrease
50-70% reduction
Improved safety
The RBI Methodology: Step by Step
Step 1: Define Scope and Objectives
Identify which equipment and systems will be included. Typically includes pressure vessels, piping, tankage, and rotating equipment.
Step 2: Collect Data
Gather essential information:
- Design specifications and materials of construction
- Operating conditions (temperature, pressure, flow)
- Historical inspection data and findings
- Maintenance and repair history
Step 3: Identify Damage Mechanisms
Determine what degradation mechanisms can affect each piece of equipment:
- Internal corrosion: Uniform, pitting, erosion-corrosion
- External corrosion: Under insulation, atmospheric
- Stress corrosion cracking: Chloride SCC, caustic SCC
- High-temperature mechanisms: Creep, oxidation
Step 4: Assess Probability and Consequence
Calculate likelihood of failure and evaluate impact across safety, environmental, and production dimensions.
Step 5: Develop Inspection Plans
Create tailored inspection plans specifying techniques, coverage, intervals, and acceptance criteria.
Implement RBI with Expert Inspectors
NDT Connect provides certified inspectors experienced in RBI-driven inspection programs.
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