The design of emergency relief systems is a highly complex topic which continues to evolve rapidly. Detailed engineering calculations must be completed to select and install proper relief systems. Due to mixed vapor-liquid streams, non-steady-state pressure driving force, reacting streams, and flow through the complex geometries of pressure relief devices and vent piping systems, simple pressure drop calculations are insufficient. This book presents a methodology which helps properly size all the components in a pressure relief system from the relief device to the stack. Enclosed with the book is a download code providing access to the CCFlow suite of design tools and the new Superchems for DIERS Lite software accompanying it, this book is essential for engineers designing chemical plants, refineries, and similar facilities.OSHA has recognized the first edition of this book as the recognized and generally accepted good practices, and expects organizations to comply with the practices in it.