The agent flows from the manifold pipe, through the remaining system pipe and discharges into the protected space through the agent nozzles. The agent nozzles are symmetrically arranged along the ceiling of the protected space with the minimum number of nozzles determined from the area coverage rating of the nozzles utilized. If the ceiling is higher than the maximum nozzle height, then an additional tier of nozzles would be required.  Sometimes more than the minimum number of nozzles required is employed to help ensure that the agent is well mixed throughout the protected space due to the geometric shape of the protected space or due to the presence of obstructions.

Typically, two types of nozzles are utilized. The first type of nozzle is the 360o nozzle that is intended to be located near the center of the protected space or portion of the protected space. The other type of nozzle is the 180o nozzle that is intended to be located near a wall of the protected space.

NOTE: This is an unformatted excerpt from our online fire protection training library.