API
API 584
Integrity Operating Windows
Limits set on process variables specifically to protect equipment integrity, tiered by how quickly damage follows an exceedance and what response is required. Distinct from product specification limits and from safety trips: crossing one means the assumptions behind the inspection plan have stopped holding, not that failure is imminent.
This is an explanation, not the standard. PipingInspector is not affiliated with API and reproduces no part of the document. Always work to the current edition of the standard itself and to your project specification.