Chapter 2 - Overpressure Protection

Abstract

This chapter defines what is considered a potential overpressure scenario in process systems and where the safety relief valves (SRVs) are needed. A pressure relief device is any device that can purge a system from an overpressure condition. More particularly, an SRV is a pressure relief device that is self-actuated, and whose primary purpose is the protection of life and equipment. Through a controlled discharge of a required (rated) amount of fluid at a predetermined pressure, an SRV must prevent overpressure in pressurized vessels and systems, and it operates within limits which are determined by international codes. An SRV is often the final control device in the prevention of accidents or explosions caused by overpressure. Pressures and flow in the process industry are controlled by electronic process systems and highly sophisticated instrumentation devices. One of the most critical steps in establishing the appropriate role and settings of the individual safety systems is the risk assessment analysis, the process in which engineers consider and analyze all possible conditions in order to select the most appropriate safety concept, which ensures safe operation under all possible circumstances and scenarios.