Where should the dry pipe valve be located?

• A. In the dry pipe enclosure near the system riser
• B. In the main water supply line
• C. In the building's mechanical room
• D. All of the above

Answer: (D)

The dry pipe valve is the control device that releases water into the dry piping when a sprinkler head is activated, so it must be located where it can effectively isolate the dry system from the water supply and be easily accessible for operation and maintenance. In practice, this valve is commonly housed in a dry pipe enclosure near the system riser for convenience and quick testing. It can also be mounted on the main water supply line if the layout places the valve there, or in the building’s mechanical room if that is where the dry-pipe equipment is installed. NFPA 14 allows these arrangements as acceptable locations, depending on the design and accessibility, so all of the above locations are possible.