Medical Gas (Med Gas) Basics. Types. Properties. Piping.

Medical Gas

 

Types of Medical Gases are based on their use:  To Heal or therapeutic gases, To Experiment or laboratory gases, and To Surgery or anesthesia

 

The methods of creating gases are different from products to products, for example for oxygen production, methods to Manufacture O₂ are:

 

• Fractional Distillation, Electrolysis of H₂O, Chemical Decomposition, Physical Separation
• Fractional Distillation
• cheapest and most common method to manufacture O₂: air is filtered to remove pollutants, H₂O and CO₂. air is then liquefied by compression and cooled by rapid expansion. the resulting mixture is heated in a distillation tower and then transferred to cryogenic storage cylinders
• Electrolysis of H₂O
• separates oxygen from water
• Chemical Decomposition
• heating of oxygen to remove impurities
• Physical Separation
• uses oxygen concentrators to extract oxygen from ambient air; produces the least amount of oxygen

 

 

A Comprehensive table for Medical Gas piping:

 

Medical Gas and Fluid
Gas	Color/ Pressure	Odor	Taste	Chemical Composition	flammable	Application, minimum flow rate: Note 1- Any room designed for a permanently located respiratory ventilator or anesthesia machine shall have an outlet capable of a flow rate of 180 LPM (6.36 CFM) at the station outlet.	Color
Air (AIR), Medical Air, Med Air	Colorless 50–55 psi	Odorless	Tasteless	78% nitrogen, 21% oxygen, and 1% trace elements.		.71 CFM per outlet1	yellow/black
Oxygen (O₂)	Colorless 50–55 psi	Odorless	Tasteless	21% of the earth’s atmosphere; Liquid oxygen exists at cryogenic temperature, -300ºF at atmospheric pressure. When warmed expand to fill a volume 860 times its liquid volume.	not flammable but does support combustion	respiratory therapy and anesthesia, .71 CFM per outlet1 (20 LPM)	Green/white or white/green
Carbon Dioxide (CO₂)	Colorless 50–55 psi	Odorless	Tasteless		does not support combustion or life.	Occasionally used for surgical procedures and laboratory applications, 0.71 CFM per outlet1	Gray/black or gray/white
Helium (He)	Colorless 50–55 psi	Odorless	Tasteless	heliox in a 80/20 or a 70/30 mixture		.71 CFM per outlet	Brown/ white
Nitrogen (N2)	Colorless 160–185 psi	Odorless	Tasteless	78% of the earth’s atmosphere		pipe joining and pressure testing purposes, to power instruments, 15 CFM (0.42 m3/min.) free air per outlet	Black/white
Nitric Oxide (NO)	Colorless 50 55 psi	Faint Odor	Faint Taste			a vasodilator and used more in the neonatal unit	black/ White
Nitrous Oxide (N₂O)/Oxide of Nitrogen	Colorless / 50 to 60 psig	Odorless/ “sweetish” smell	Tasteless	Exists as a gas at atmospheric conditions		used as an anesthetic, Capable of producing the first and second stages of anesthesia when inhaled, Oxygen is released under conditions of combustion, creating an oxygen-enriched atmosphere, .71 CFM per outlet	light blue
Oxygen/carbon dioxide mixture O2CO2n (n is % of CO2)	50-55 psi						Green/white
Waste Anesthesia Gas Disposal (WAGD)				as “scavenging” or” evacuation		capture and carry away gases vented from the patient breathing circuit during the normal operation of gas anesthesia or analgesia equipment; can be connected to the medical surgical vacuum system under certain conditions but discouraged.	Violet/white
Medical Air (MA)	50 to 60 psig			The quality of the local ambient air should be considered prior to its selection for compressors and treatment equipment.		Medical air is supplied from cylinders, bulk containers, medical air compressors and treatment equipment, or has been reconstituted from oxygen and nitrogen; Exclusively used for human respiration or calibration of devices for respiratory application; Primarily used for respiratory therapy; Hydrocarbon carryover from the compressor poses a threat to the end user and increases the risk of fire especially when mixed with oxygen; A medical air compressor is designed to exclude oil from the airstream and compression chamber and that does not under normal operating conditions, or any single fault, add any toxic or flammable contaminants to the compressed air.
Instrument Air (IA)	200 psig			Substitute for nitrogen for powering instruments unrelated to human;		respiration (surgical tools, ceiling arms, etc.); Medical air and instrument air are distinct systems for mutually exclusive applications.
Medical Vacuum (MV)	15″ to 30” Hg			An assembly of central vacuum producing equipment and a network of piping for patient suction in medical, medical-surgical, and waste anesthetic gas disposal(WAGD) applications		Primarily used for patient treatment in surgery, recovery, and ICU to remove fluids and aid in drainage.1 SCFM (0.03 sm3/min.) per inlet. For testing and certification purposes, individual station inlets shall be capable of a flow rate of 3 SCFM, while maintaining a system pressure of not less than 12 inches (305 mm) at the nearest adjacent vacuum inlet.	White/black
Nonmedical air (level 3 gas-powered device)							Yellow-and-white diagonal stripe/black
Nonmedical and Level 3 vacuum							White-and-black diagonal stripe/black boxed
Laboratory air							Yellow-and-white checkerboard/black
Laboratory vacuum							White-and-black checkerboard/black boxed
Other mixtures				Gas A%/ Gas B%			Colors as above Major gas for background/ minor gas for text
Instrument air	160–185 psi						Red/white