During a monthly SCBA inspection, how far must the purge valve be turned counterclockwise to ensure air flow?

During a monthly SCBA inspection, ensuring proper functionality of the purge valve is critical for the safe operation of the equipment. The purge valve is specifically designed to release air when turned, and it is important to know how far to turn it to establish an adequate airflow for testing and protective purposes.

Turning the purge valve a half turn counterclockwise is generally sufficient to achieve the necessary airflow. This amount allows for an adequate volume of air to be released without compromising the integrity of the SCBA system. It is essential to ensure airflow during inspections so that firefighters can verify that the equipment is functioning correctly and is ready for use in emergency situations.

The other options might not allow for sufficient airflow as they either fall short or exceed what is needed for a proper inspection. A quarter turn may not release enough air, while three-quarters or a full turn could potentially lead to an unnecessary loss of pressure or create complications in maintaining equipment integrity. Thus, a half turn is the most effective approach for achieving the desired outcome.