To shut off oxygen, or any other gas fed through a zone valve box, one must pull the cover off (usually by a pull ring) and pull the handle outward toward themselves. Prior to closing any medical gas valve, confirmation should be made to confirm that any patients connected to the system have an alternate means of receiving the specific gas(es) being shut off.
Below are some frequently asked questions regarding zone valve boxes and code compliancy. Consult your NFPA 99C Gas and Vacuum Systems, 2005 Edition for Level 1 Systems for more information.
Do all outlets and inlets have to be supplied through a zone valve box?
Yes. All station outlets and inlets must be supplied through a zone valve box.
Where should a zone valve box be placed?
Zone valves must be placed with an intervening wall between it and the outlets and inlets and must be visible and accessible at all times. They may not be located behind normally open or closed doors or otherwise hidden from plain view and can not be inside closed or locked rooms or closets.
Each vital life support, critical care and anesthetizing location in each medical gas and vacuum line must be located so it is readily accessible in an emergency. It must also be arranged so that shutting off the supply to any one operating room or anesthetizing location will not affect the others.
Can a zone valve box control medical gas on another floor? No. Zone valves can only serve outlets and inlets on the same story and must not affect the supply of medical gas or vacuum to another zone or the rest of the system.
Does a zone valve box require a gauge? Yes. Each valve within the zone valve box must have a pressure or vacuum indicator (gauge) downstream of the valve (piping must be from left to right).
Besides outlets and inlets, what else must a zone valve box have? All gas delivery columns, hose reels, ceiling tracks, control panels, pendants, booms or other special installations must be supplied from a zone valve box.
What special labeling does a zone valve box require? All zone valves must be labeled with the name or chemical symbol for the specific medical gas or vacuum system, with the room or areas served and must indicate “use caution when opening or closing the valve or valves in an emergency” (Valves that control Vacuum and WAGD must be labeled for both).
Zone valves are a commonly overlooked part of most medical gas systems because they are usually only used in an emergency. If an emergency should arise, don’t you want to be ready? Make sure the staff in your facility knows where the zone valves are and what they are used for if they don’t already know.
