Properly functioning PRDs are considered to be the critical “Layer of Protection” for pressurized systems; they are essential for avoiding unexpected overpressure events, equipment damage, loss of containment, and plant shutdowns.
Regular inspection, testing, and overhaul of PRDs are needed to ensure proper function upon demand. Most inspection programs adequately manage the unreliability of PRDs without much consideration to potential consequences of PRD failure to open or leakage.
Many plants inspect PRDs on preset intervals as recommended by inspection Codes such as NB-23 and API 510. These Codes allow for an increase in inspection intervals based on the historical performance of the PRD.
The use of an RBI methodology allows optimum intervals to be set immediately based on the probability and consequences associated with PRD failure. This enables you to plan maintenance programs based on risk and prioritizes resources in the following ways:
API PRD RBI methodology evaluates the criticality of PRDs and sets inspection/testing frequencies accordingly. This quantitative approach is consistent with API 510 Pressure Vessel Inspection Code and employs extensive computational analysis by considering the following:
This is an optimized approach to PRD inspection as compared to the traditional condition-based PRD inspection program. It has the potential to significantly reduce maintenance costs without jeopardizing the safety of the plant.
E2G is uniquely qualified to implement the API PRD RBI technology because we are recognized industry leaders in risk-based inspection and pressure relieving systems.
Philip Henry, P.E., an expert in pressure relief systems, led the development of the API PRD RBI methodology as Chairman of the API RBI Technical Working Group. Phil is also the API Pressure Relieving Systems (PRS) Subcommittee chairman of TF520, which delineates standards associated with the sizing, selection, and installation of PRDs.
Download RBI Case Study: PRDs
Our Help Desk IT specialists and engineers are available for questions about all E2G products. Our goal is to facilitate upgrades and conversions, quickly answer your questions, and help you benefit from our state-of-the-art software products.
Weekdays 9am – 4pm ET