In the 2002 edition of NFPA 99C, there are requirements for Instrument Air which are still the same for 2005 however, the 2005 Edition has a new section for support gases.
What are support gases?
Support gases are gases used for powering pneumatic devices related to patient care, such as medical-surgical tools, equipment .booms and pendants.
What are the changes in 2005?
In the 2005 edition, nitrogen, as well as instrument air (not medical air), may be used as support gases. In the 2002 edition this section did not exist, which left only instrument air as a support gas.
Since instrument air is relatively new, most facilities have been using nitrogen to control equipment brakes and also to power surgical tools.
In the 2002 edition, oxygen, nitrous oxide, compressed air (medical air), carbon dioxide and nitrogen were all considered to be medical gases.
In the 2005 edition, oxygen, nitrous oxide, compressed air (medical air), carbon dioxide and helium are considered medical gases. Nitrogen has been removed and helium has been added.
Nitrogen and instrument air are now considered to be support gases. Nitrogen is no longer considered medical gas since it is not used for respiration.
How do I pipe Nitrogen or Instrument Air into a ceiling column or boom for brake systems?
All gas delivery columns, hose reels, ceiling tracks, control panels, pendants, booms, or other special installations shall be located downstream of the zone valve box. These systems usually need regulation to lower the normal operating line pressure of nitrogen, which is 165 psig. The installing contractor or supplier of equipment typically supplies the regulator, which should be located above the ceiling.
Should I use Instrument Air instead of Nitrogen?
Instrument Air is an alternative to nitrogen and allows facilities to generate instrument air by means of a compression system similar to that of a medical air system, but with much higher operating pressures and increased filtering requirements.
Since Instrument Air systems differ completely from that of Nitrogen systems, it would be inconceivable to change a complete nitrogen system over to an instrument air system.
Nitrogen has been widely used as a means of powering surgical instruments for years, and that will most likely continue. New facilities have more options during the design process and may want to consider an instrument air system, which can reduce costs associated with nitrogen usage and with cylinder or container demurrage.
By:
Jay D’Agostino
Vice President of Operations
ASSE 6020 Medical Gas Inspector
ASSE 6030 Medical Gas Verifier
