Where is the outside stem and yoke valve typically located?

The outside stem and yoke valve is generally located in mechanical rooms because this is where the building's plumbing and fire protection systems are commonly housed. Mechanical rooms serve as central points for equipment that control various mechanical systems within a building, including those associated with water supply for fire suppression systems. The outside stem and yoke valve specifically regulates the flow of water from the water supply into the system, making it essential to have it easily accessible for maintenance and emergency operations.

Its location in mechanical rooms ensures that firefighters can access the valve quickly while maintaining safety protocols and facilitating efficient water supply management during a fire incident. This choice reflects a standard practice in building design and fire safety, as opposed to the other options which do not typically represent common locations for such vital firefighting equipment.