What is the composition of air?
78% Nitrogen, 21% Oxygen, 1% Trace gases (CO₂ and Argon)
What are the properties of air?
Non-flammable, supports combustion, colorless, odorless, tasteless, supports life
What is the primary use of oxygen (O₂) in medical treatment?
Treatment of hypoxemia
What methods are used for the manufacture of oxygen?
- Fractional Distillation
- Physical separation (Oxygen concentrator, Oxygen enricher)
Describe the process of fractional distillation.
Air is scrubbed and cooled until liquid, evaporates at different temperatures, each gas siphoned off separately, remaining gas cooled and repeated.
What is the role of carbon dioxide (CO₂) in medical applications?
Combined with oxygen for severe airway obstruction, used in pulmonary function testing.
What are the color codes for medical gases?
- Air – Yellow
- Carbon Dioxide – Gray
- Oxygen – Green
- Helium – Brown
- Nitrogen – Black
- Nitrous Oxide – Light Blue
- Nitric Oxide – Silver
- Helium/Oxygen – Brown/Green
What is the normal filling pressure for medical gas cylinders?
2000 psig (can exceed by 10%)
What regulations govern medical gas cylinders?
- FDA – regulates oxygen purity
- DOT – regulates manufacture, storage, transport
- CGA – ensures interchangeability
- NFPA – regulates safe use and storage
What safety measures should be taken with medical gas cylinders?
- Must be secured
- Separate full and empty cylinders
- Keep caps on during transport
- Close valves when not in use
- Use correct regulators & gauges
What is the formula for calculating cylinder duration?
Duration = (PSIG × Factor × 60) / Flow (L/min)
What is the conversion ratio of liquid oxygen to gaseous oxygen?
1 cu ft liquid O₂ = 860 cu ft gaseous O₂
What is the purpose of the pressure reducing valve in liquid oxygen systems?
Maintains 50 psig output
What are the characteristics of portable liquid systems?
Home care / hospital transport, provides 8–12 hrs oxygen
What are the requirements for piping systems delivering medical gases?
- Deliver 50 psig to all outlets
- Pipes labeled every 20 ft
- No oil contact
What technology do oxygen concentrators use to produce O₂?
- Semi-permeable membrane
- Molecular sieve concentrator
What is the function of a flowmeter in medical gas systems?
Regulate flowrate from a 50 psig source
What type of flowmeter is most commonly used?
Thorpe Tube (compensated)
What is a Bourdon Gauge?
An adjustable pressure gauge that regulates flow, not backpressure compensated.
What is the pressure range for high flow specialized flowmeters?
0–75 L/min
True or False: Carbon Dioxide (CO₂) supports life.
False
