Zone Valve Code Requirements
Zone valves are an integral component of your medical gas pipeline distribution network. They allow for the isolation of specific system areas in the event of an emergency, required maintenance, or planned shutdowns related to renovations and modifications. Per the NFPA 99 2012, all station outlets/inlets shall be supplied through a zone valve as follows. (1) The zone valve shall be placed such that a wall intervenes between the valve and the outlets/inlets it controls. (2) The zone valve shall serve only outlets/inlets located on that same story. (3) The zone valve shall not be located in a room with station
outlets/inlets that it controls. The NFPA 99 2012 also states that Zone valves shall be readily operable from a standing position in the corridor on the same floor they serve. The zone valves shall be so arranged that shutting off the supply of medical gas or vacuum to one zone will not affect
the supply of medical gas or vacuum to another zone or the rest of the system. A pressure/vacuum indicator shall be provided on the station outlet/inlet side of each zone valve. Finally, zone valve boxes shall be installed where they are visible and accessible at all times.
Zone Valve Locations
The NFPA 99 2012 prohibits the following locations for zone valve boxes. Zone valve boxes shall not be installed behind normally open or normally closed doors or otherwise hidden
from plain view. They also shall not be located in closed or locked rooms, areas, or closets. Finally, they shall not be blocked by equipment, stretchers, or any other object that will affect someone shutting off the valves.