What is support gas and what are the uses?
Nitrogen and Instrument Air are support gases. These gases are not used for respiration, but are used to power pneumatic devices such as medical and surgical tools, equipment booms and pendant arms.
Do I need a medical gas zone valve box for support gas?
Most applications requiring support gases will have a need for a medical gas outlet (nitrogen or instrument air). Medical gas outlets are needed in order to connect and disconnect pneumatic tools. As per NFPA requirements, all station outlets and inlets shall be supplied through a zone valve box.
Do I still need a zone valve box if I don’t need a medical gas outlet and the support gas is only controlling a boom brake or pendant arm?
Yes. NFPA requires all gas delivery columns, hose reels, ceiling tracks, control panels, pendants, booms, or any other special installations to be located downstream of a zone valve box.
Do I need master alarm signals for support gases?
Yes. The master signals needed will depend upon the type of distribution system being used but all the required signals will need to terminate at two master alarm panels. One panel should be located in the office or work space of the person responsible for maintaining the medical gas system. The other panel should be located in an area with continuous observation (24 Hour).
Do I need an area alarm for support gases?
Yes. Support gases are required to have an area alarm located at a nurse’s station or other similar location that will provide for surveillance. The alarm should activate if the line pressure increases or decreases by 20 percent of the normal operating pressure.
Can I use medical air as a support gas?
No. Medical air sources used for human respiration and calibration of medical devices for respiratory applications cannot be used as a support gas. 
