At 11:00 a.m. on April 10, 2023, Employee #1, 55, was performing maintenance on the refrigerant lines of a Liquid Chiller used for air conditioning at an airport terminal. Employee #1 was removing the Electronic Expansion Valve (EEV) from the hot gas bypass line. The line contained R-22 refrigerant and compressor lubricating oil at a pressure of approximately 100 pounds per square inch.
NOTE: R-22 may explode if heated.
A coworker was summoned to assist in separating the pipe joint. The coworker placed a set of pliers on the pipe joint as Employee #1 applied heat with an acetylene torch. As the pipe joint heated, the brazing material melted, and the joint was separated by the coworker with pliers. The pipe joint opened to the atmosphere, causing a pressure release of R-22 refrigerant and compressor lubricating oil. The compressor oil ignited from the heat of the pipe joint.
A flame front was expelled into Employee #1, causing burn injuries. Employee #1 was killed.