The emergency relief system (ERS) design of a vessel is an important safeguard that provides protection against various overpressure scenarios. A common overpressure scenario is a runaway reaction which can be caused by an upset condition for a reactive chemical operation. The Design Institute for Emergency Relief Systems (DIERS) has identified accepted methodologies to characterize two-phase flow venting for reactive chemical systems where runaway reactions can occur.This webinar will review the relevant codes, standards and design practices that are applicable for ERS design. Equipment used for ERS design will be reviewed with advantages and limitations for each. Concepts such as low-phi factor calorimetry data, system types and effluent handling considerations will be covered. More detailed information will be provided regarding using low phi factor calorimetry to evaluate the 3 types of systems: vapor, hybrid and gassy. This webinar is intended to provide an overview of ERS design and relevant DIERS methodology for reactive chemical systems.