Flare systems are the most commonly used control devices that are installed to ensure that emergency releases of toxic gases are destroyed to comply with safety and environmental regulations. It consists of multiple relief valves discharging into a common flare manifold or header system. A key item influencing the flare system design is the allowable relief valve backpressure. The system pressure drop from each relief valve discharge through the flare tip must not exceed the allowable relief valve backpressure for all system flow conditions. The allowable backpressure is typically limited to about 10% of the minimum relief valve upstream set pressure for conventional relief valves.