(88a) Safe Management of Unforeseen Delays in Mechanical Integrity Inspection Schedules

The days of ?frequent? annual maintenance outages where mechanical integrity testing and inspections can be performed are gone. The new reality of modern industrial gas and chemical plant operation includes expectations of ever increasing durations between scheduled maintenance down time that have sometimes reached 5 years and beyond. In addition, in the interest of keeping initial capital cost under control, there is constant pressure to restrict redundant architectures and systems intended to allow on line maintenance.

Required safety systems that have the potential for unrevealed failures leads to a requirement for plant down time to properly test and inspect those systems. Because our customers desire high reliability with long runs between maintenance outages it is prudent to design our facilities and mechanical integrity (MI) plans to meet the agreed commercial strategy. However, unforeseen events can cause delays in maintenance outages and thus our window to complete mandatory non-deferrable MI activities. Air Product's process for reviewing the consequence and likelihood of these delays allows appropriate action to be taken to ensure continued safe operation while complying with customer needs to reschedule downtime windows to the greatest extent possible.

This paper outlines the procedure used to review and manage the effects of inspection and test delays on facility risk. The hazard review process is administered and documented through the company's existing Management of Change process. The review itself is handled using a team with diverse technical expertise that can uncover and address key factors affecting safety. Levels of required management approval and Process Safety representation varies based on the expected length of the planned delay. Duration of the extension dictates the level of technical reviews and provides guidance as to the whether qualitative or quantitative techniques are appropriate. In either case, mitigation techniques may be used to temporarily manage the increased level of risk associated with the inspection or test delay.

Implementation is challenging as the plant culture migrates from one of local decisions and control to one of understanding the multidisciplinary impact these delays create. The preferred solution is always to find a way to perform the task as planned or by using alternate ?on stream? inspection methods without requiring an extension review.