Medical Gas and Vacuum Systems Flows and Pressures
FAQ [Health Devices Jul 1996;25(7):263]
Hospital: What are the flows and pressures required for medical gas and vacuum systems?
ECRI: The National Fire Protection Association's (NFPA) Standard for Health Care Facilities, NFPA 99, which defines medical gas and vacuum systems in the United States, somewhat obscurely defines the flows and pressures required for medical gases in section 4-18.104.22.168(h) of the 1996 edition. According to this standard, each oxygen, nitrous oxide, and medical compressed air outlet must deliver a flow of at least 100 L/min (3.5 SCFM) at 50 to 55 psig (345 to 380 kPa gauge) with a system static pressure of 50 to 59 psig (345 to 407 KPa gauge). Nitrogen outlets, which are used to power gas-driven surgical tools, must deliver a flow of at least 140 L/min (5.0 SCFM) at 160 to 200 psig (1,103 to 1,379 kPa gauge) with a system static pressure of 160 to 239 psig (1,103 to 1,648 kPa gauge).
These flows and pressures correspond to the minimum requirement for most gas-using medical devices. In other countries, the pressures and flows are defined by such standards as ISO 9170, Terminal Units for Use in Medical Gas Pipeline Systems (Europe); CSA Z305.1, Nonflammable Medical Gas Piping Systems (Canada); or JIS T 7101, Medical Gas Pipeline Systems
(Japan), and are similar to those defined in NFPA 99.
Vacuum system inlets are required to draw 85 L/min (3 SCFM) at one inlet and not cause the pressure at an adjacent inlet to drop below 12 inches of mercury (305 mm Hg), the minimum allowable system pressure. (Refer to NFPA 99-1996 section 4-22.214.171.124.)
Medical Gas and Vacuum Systems [18-046]