NM-GEN membrane nitrogen generators extract the available nitrogen from the compressed air. Membrane nitrogen generators use hollow fiber membrane technology to separate nitrogen from other components in the compressed air. The membrane uses the principle of selective permeability to produce purity nitrogen. Each gas has a characteristic permeability rate, which is a function of its ability to diffuse through a membrane. Oxygen is a fast gas and diffuses selectively through the membrane wall, while nitrogen is allowed to travel along the inside of the fibre, creating a nitrogen-rich product stream. The oxygen-enriched gas, or filtrate, is vented through the membrane separator at atmospheric pressure. Most of the slow gases and a very small amount of the fast gases continue to travel through the fiber until they reach the end of the membrane separator, where the nitrogen gas product is injected into the application.