What is a pressure demand respirator?
It is any respirator that maintains a static or a dynamic pressure inside the facepiece, which is greater than the atmospheric pressure outside the facepiece. Air is supplied to the facepiece only when the pressure inside the facepiece falls to a predetermined level. A user’s breathing rate would determine how quickly this would occur. If a user breathes heavily, such as when running up a flight of stairs, the air is supplied at a faster rate. It the user is at rest, less air is supplied. In other words the air is provided “On Demand” as the user needs it.
