On February 28, 2020, an employee, 36, was tasked with replacing a gasket in a 6-inch bolted flange on top of the Platformer Heater at an Oil Refinery. The employee was working in a man basket on top of the Platformer Heater. The employee loosened the bolted flange while using hand tools to remove a leaking gasket. Flammable gas and fluid from the opened gasket began escaping to the open atmosphere. Flammable gas and fluid found an ignition source, causing…