Gas Cylinders Flashcards
Compressed Gas (nonliquified) Defined
Remains gas at ordinary temp & pressure, at very low temp becomes “cryogenic liquid”
Examples of nonliquified gas
Oxygen, nitrogen, helium, air
Compressed Gas (liquified) Defined
Becomes liquid in a container at ordinary temp & pressure
Examples of liquified gas
Carbon dioxide, nitrous oxide
Non flammable gas definition
will not burn, supports combustion or explode - some can extinguish flames
Combustion supporting gas definition
Increases rate/intensity of anything thats burning/could burn. Minimum of 15 feet from flame
Flammable gas definition
can be readily ignited, explosive in the presence of oxygen
What would you do with a fire in the airway?
Turn off oxygen and pull ETT quickly
Air - color code, price, compressed?
Yellow, usually free & readily available, can be compressed from the atmosphere, may also be synthetically produced
Helium - color code & characteristics
Brown, chemically inert, lighter than air, colorless, odorless, nonflammable, will not support life
Oxygen - color code, characteristics
Green, colorless, odorless, tasteless, supports life, non-flammable, supports combustion, liquid at -300 F, produces oxides in combinations
HeliOx - what it is
Helium/Oxygen mixture, usually 20-40% O2. Reduces airway resistance, most commonly used because it reduces airway fires during laser surgery
Nitrous Oxide - color code, characteristics
Blue, 75-80% in liquid form (at room temperature is a liquid at 747 psig). Will not get low reading until all liquid is gone
A full E cylinder contains how much nitrous oxide?
1590 L
Carbon Dioxide - color code, characteristics
Grey, colorless, odorless, acidic taste, will not support life, non-flammable/does not burn,
How much carbon dioxide comes in and goes out per minute normally?
250 in, 200 out per minute, some of it is metabolized
Most common gas cylinder in health care?
E cylinder
How much oxygen does an E cylinder hold?
660 L at 1900 psig
How much oxygen does a H cylinder hold?
6900 L at 2200 psig
What color code is nitrogen
Black
What does psig mean?
pounds per square inch gauge, difference between measured pressure & surrounding atmosphere.
Calculating cylinder gas volume (equation)
Duration of gas flow in minutes =
gauge pressure (PSI) x cylinder conversion factor (0.28)
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gas flow (L/min)
If you have 1200 psi and gas flow is running at 4 L/min, how long do can you run on that tank?
84 minutes
What is the pin index safety system?
PISS - each gas has it’s own unique PIN position so the wrong cylinder should not be able to be mounted
Cylinder safety
Only handled by trained personnel, no oil/grease/lubricants on valves/regulators/gauges or fittings, Temp -7 C to 54 C, tight connections, do not obstruct pressure relief device, do not cross use regulators/hoses, do not use reducer adapters, keep valves closed when not in use, ID cylinder, remove cover, check for washer, PISS, open slowly, check reading
Central oxygen contains how much?
7.3 million L O2
NFPA requirements for liquid oxygen supply
25-50 ft from hospital or flammable gas/gas storage or wooden structure, on asphalt/concrete, fenced, posted no smoking/open flame
What is diameter index safety system?
DISS - prevents pipeline from wall being connected to the wrong inlet on the machine
What does the US Department of Transportation do for gas cylinders?
Regulates construction & handling of all medical compressed gas cylinders (design, construction, testing, marking, labeling, filling, storage, handling, maintenance, transportation), requires periodic visual inspection, inspecting cylinders every 5 years for dents, gouges, arc burns, & physical stress. Also transportation of gas cylinders
How to test cylinders
Hydrostatic test checks for leaks, cylinder expansion & wall stress – cylinder is filled with water and then submerged in water, it is then pressurized to 3000 psig which will cause slight expansion - should return to original size when pressure is released with no change in water level measurement.
How does a cylinder fail a test?
If it displaces more water after than before pressurization, it has residual expansion– if it’s s original size can use it for 5 years, if more than 10% it will be removed from medical use
