Heat integration is commonly skipped when evaluating a process' relief systems design. Failing to evaluate the heat integration (or energy balance) for a process can result in overly conservative results and possibly lead to costly expenditures. Evaluating the effects of heat integration in relief systems design is a process that evaluates the physical limitations of the system and does not require taking credit for control system response. It is important to understand the effects that heat integration has on both individual relief devices, and in some cases, the significant affect it can have on flare system design. This becomes even more imperative in cases where relief devices that once discharged to the atmosphere are modified to discharge into a closed flare system. This article covers two examples where evaluating the effects of heat integration on the relief systems prevented costly modifications to those systems. (c) 2013 American Institute of Chemical Engineers Process Saf Prog, 32: 244-247, 2013