API BULL 592 : 2025

Mechanical integrity (MI) is a key pillar in safe operation of any process facility. The term mechanical integrity (or asset integrity) applies broadly to all equipment types including fixed equipment, rotating equipment, mitigation equipment (lower explosive limit, deluge, gas detector, suppression), and instrumentation/controls. Inspection, testing, and preventive maintenance tasks for each equipment type are crucial for safe operation and reliability of a process facility.

The purpose of this document is to provide guidance on the MI program for the different types of fixed equipment. Other process equipment, such as rotating equipment and instrumentation/controls, are not covered in this document. Development of MI programs in various industries involves interpretation of regulations and case-by-case decision making, depending on the complexity of the equipment. The contents of this document are intended to assist in determination of:
- the key elements and considerations in developing a fixed equipment MI program based on process safety management (PSM) guidelines/principles (or best practices);
- how API documents and other codes, standards, and guidance documents fit into the MI program.