Incorporating Abnormal Modes of Operation into Pressure Relief System Design and Documentation

Pressure relief systems are commonly referred to as the last line of defense in oil refineries and chemical facilities; however, the design of pressure relief systems does not typically consider abnormal modes of operation such as startup, shutdown, and other temporary operations. Past studies have shown that a majority of incidents occur during abnormal modes of operation including several significant incidents that helped shape the state of process safety as it is today. This paper will review potential sources of overpressure during various abnormal modes of operation and analyze how these overpressure scenarios can be incorporated into pressure relief system design and documentation.