In the hazardous process industries, commonly referred to as the “EX” and “HazLoc” industries, static electricity is generated frequently. Various grades of crude oil, refined petroleum products like LPG, and numerous chemicals fall into a category of materials known as “static accumulators”.

During a typical rail tanker loading operation, the static accumulating product is transferred from a storage tank via a gantry loading system into a receiving rail tanker. The transfer process electrostatically charges the product as it moves through the pump, filtration and piping system.

If the rail tanker is not directly connected to the earth, electrostatic charges accumulate on its surface, causing its voltage to rise rapidly. The tanker then seeks to discharge excess potential energy, with the most efficient method being a static spark.