(21a) Enhanced Integration of Mechanical Integrity with HAZOP and LOPA

Keywords: American Institute of Chemical Engineers (AIChE), Center for Chemical Process Safety (CCPS), Hazard and Operability Study (HAZOP), Layer of Protection Analysis (LOPA), Mechanical Integrity (MI), Occupational Safety and Health Administration (OSHA), Process Hazard Analysis (PHA), Process Safety Management (PSM).

Abstract

An emphasis on process safety and risk management is paramount to the upstream, midstream, downstream, and chemical industries. Fundamental to this focus are Hazard and Operability Studies (HAZOPs) and Layer of Protection Analyses (LOPAs), two process hazard analysis (PHA) methodologies that identify, assess, and manage potential risks in process systems. On another front, Mechanical Integrity (MI), which ensures that process equipment is fabricated, installed, and maintained correctly, also plays a pivotal role in risk mitigation. While HAZOPs, LOPAs, and MI all strive towards the same goal, their integration in many industries remains siloed.

This paper presents a compelling argument for a more comprehensive approach to process safety and risk management by enhancing the integration of Mechanical Integrity with HAZOPs and LOPAs.

More specifically, this paper will explore the following:

1. Shared goals but fragmented approaches: Despite having congruent objectives, the independent execution of HAZOPs, LOPAs, and MI often leads to overlooked vulnerabilities. This misalignment can inadvertently produce gaps in the identification of hazards and the subsequent mitigation strategies.
2. Synergy in integration: A combined approach fosters improved communication between different teams, ensuring that design, operation, and maintenance perspectives are balanced. This integrated methodology maximizes the efficiency and effectiveness of hazard identification and mitigation. Elements to be discussed include (1) safe operating limit development in alignment with current and accurate mechanical integrity inspection and testing information and (2) practical integration of MI program deliverables and timing thereof with PHA schedule.
3. Mechanical failures as root causes: Many incidents in the industry trace back to mechanical failures—issues directly addressed by MI. By combining MI's hands-on approach with the rigorous analysis of HAZOPs and LOPAs, organizations can attain a richer and more complete understanding of potential risks. Additionally, impractical MI initiating events for risk assessment will be discussed.
4. Continuous improvement and feedback loop: Integrated systems can cultivate a continuous feedback mechanism. Insights from MI can feed into the HAZOP and LOPA processes. These insights can refine and update risk assessments and, in turn, guide MI practices more purposefully. More specifically, this element will address opportunities for enhanced risk assessment by closing the design and maintenance gaps to afford more refined hazard analysis and credible safeguard assignment.

The union of Mechanical Integrity with HAZOPs and LOPAs stands to offer industries a more comprehensive, efficient, and effective approach to process safety and risk management. As industries continue to evolve, so should our PHA strategies in ensuring process safety.

The target audience for this paper is anyone whose responsibilities include (1) leading within an organization required to comply with OSHA 1910.119, (2) establishing effective HAZOP and LOPA guidance documents, (3) developing MI protocols and checklists, and (4) participating on PHA teams to identify, assess, and manage process safety hazards.