AN AIR HOSE FITTING ON THE LUBRICATION TRUCK WAS LEAKING AIR. HE TOOK THE HOSE OFF THE TANK AND DOING SO THE AIR WAS RELEASED FROM THE TANK. THE FITTING TO BE BRAZED EXTENDED 1/4 INCH ABOVE TH E INSIDE BOTTOM OF THE AIR TANK. THERE WAS APPROX 1/4 INCH OF LIQUID ""AIR DRY"" (FLAMABLE) STILL IN THE TANK. WHEN HE TOUCHED THE FITTING WITH A TORCH FLAME THE FUMES IGNITED & FLASHED ON HIM.