True or false, cleaning the screen in the fog nozzles is part of the back-flushing procedure.

Cleaning the screen in the fog nozzles is indeed part of the back-flushing procedure. Back-flushing is a method used to clean out debris and ensure that the nozzle operates effectively. Fog nozzles, often designed for firefighting or other applications, can become clogged with particles over time, which can inhibit their performance.

During the back-flushing process, water is reversed through the system, which not only helps to clear the nozzle itself but also allows for any screens or filters attached to be cleaned out as well. This is crucial for maintaining optimal flow and spray patterns, which are essential for the efficiency of fog nozzles in their intended use.

Other options do not address the necessity of cleaning the screen in this specific context, which is why they do not align with the correct procedure.