‘A component of a relief system. A relief valve is a device which protects against excessive pressure in a process. The relief valve and associated downstream piping and process equipment make up the full relief system. There are many types of relief devices including but not limited to spring operated relief valves and rupture disks.
References: Adapted from D.A. Crowl and J.F. Louvar. Chemical Process Safety. 3rd Edition. Prentice Hall. Boston. MA. 2011.