Purging

Oxygen, air, and other oxidizers must be completely removed from the piping systems of any industrial system that is to contain gaseous or liquid hydrogen before any hydrogen is pumped into the system. This removal of oxygen, air, and other oxidizers is referred to as "purging" the system. Purging should be done to prevent the formation of flammable mixtures and can be accomplished in several ways. Piping systems and vessels intended for gaseous hydrogen service should be made inert by suitable purging or evacuation procedures. If the piping systems are extensive or complicated, successive evacuations broken first by an inert gas and finally with hydrogen are most reliable. This process is called "inerting."

To learn more about Hydrogen Fuel Cell Safety visit our Hydrogen Fuel Cell Safety Online Training web page.