Advancements in Integrity Management - Obtaining Greater Value from Thickness Data

Introduction

Inspection intervals for equipment have in the past been defined in a prescriptive manner. However, industry is now embracing the Risk Based Inspection (RBI) approach which in contrast prioritises inspections based on an assessment of the risk to each individual item.

The key outcome of any RBI scheme is a prioritised and focused inspection schedule. This ensures high-risk items get correct scrutiny and produces a safety-focused and cost-effective inspection scheme. RBI is now recognised as a key tool in meeting legislative requirements, as detailed in the HSE’s best practice guidelines.

There are many RBI schemes in use, but they have a number of common elements:

• Assessment of the credible threats to an item of equipment
• Potential failure modes and mitigation measures
• Resulting consequences
• Associating a measure of risk with each item
• Combining risk with inspection history to determine future inspection intervals and methodologies.