What action is required to close the purge valve?

The action required to close the purge valve involves turning it away from the face by 3/4 of a turn. This specific motion ensures that the valve fully closes, preventing any unintended release of air. Proper valve closure is critical in maintaining the safety and effectiveness of respiratory protection equipment, as it helps to secure the integrity of the breathing apparatus during use.

The process of turning the valve away from the face is generally designed to avoid any accidental opening that could occur if the valve were manipulated in another manner. Each type of valve may have different mechanisms for closure, but in this case, the specified turn aligns with standard operating procedures for ensuring that the valve is securely closed.

This action not only contributes to the operational efficiency of the equipment but also ensures that the user can breathe safely without the risk of contamination from the environment due to an open valve.