US EPA’s flare velocity limits were originally issued in 1986. Since then, they have found their way into flare regulations around the world. They were developed following a series of EPA sponsored tests conducted in the 1980’s that examined how various flare operating parameters, including velocity, affect flare performance. The limits were established using only one or two data points from a limited data set. Surprisingly, there is no evidence in the 1980’s data that high velocity in any way degrades flare performance. So how did we end up limiting flare velocity to, in most cases, 60 feet per second? What impact has this had on flare design and emissions?
CleanAir has prepared a short white paper that describes the history of these limits. It also reviews the new flare data that has been collected over the past 10 years. The new data reinforces the 1980’s data showing no flare performance degradation at higher velocities. In fact, flare combustion is improved at higher velocities.
It’s time for EPA to consider either scrapping flare velocity limits entirely, or at least significantly modifying them. Given the recent issues permitting multi-point ground flares which require high velocity to properly function, a change in regulation is needed and would be welcomed by flare vendors and users alike.
Hit the button below to receive your copy of the CleanAir white paper on flare velocity.