If you’ve ever passed an oil well or petroleum refinery, you may have noticed the vertical steel cage climbing high into the air, with an ever-burning flame at the top, and perhaps wondered about its purpose. The object, known as a flare stack, is used to dispose of flammable gases released by pressure-release valves, aimed at preventing a dangerous buildup of these gases. These stacks need regular inspections that require mandatory shutdowns that last for days, a high-risk vertical climb, and enduring temperatures in the hundreds of degrees.