Abstract: A system for eliminating start-up flaring in a gas plant utilizing flare stack diversion logic comprises a natural gas source; a start-up train flow-path; a running train flow-path; a bypass flow-path; and a flare stack diversion controller, wherein the flare stack diversion controller is programmed to execute flare stack diversion logic comprising: detecting one or more natural gas feed parameters during start-up, receiving the one or more natural gas feed parameters, determining whether the one or more natural gas feed parameters fall outside pre-defined bounds, generating an alert or message to close the block valve, determining whether the block valve has been opened, closing a start-up train flow valve upon determining the block valve has been opened, and diverting all flow from the running train flow-path to the start-up train flow-path to eliminate start-up flaring of the natural gas feed.