Oxy Flashcards
(41 cards)
3 main uses/applications for oxygen?
- High purity Dry Breathing Oxygen (DBO) on-board aircraft systems
- Medicine (high purity breathing oxygen containing moisture)
- Cutting and welding
Warnings regarding DBO?
While it is acceptable to use dry breathing oxygen (DBO) for medical use in an emergency, the use of either medical oxygen (which contains moisture) or industrial oxygen (which contains a higher amount of impurities) in an aircraft oxygen system is strictly forbidden. Medical and industrial oxygen are to be used for their stated purposes only
The earth’s atmosphere is comprised of a mixture of gases. What is the concentration of each?
Oxygen - 20%
Nitrogen - 78%
Water vapour - 1-2%
Trace quantities of other gases
When your body is starved of oxygen, it doesn’t function to its full capacity.
What 2 conditions can occur?
- Нурахіа
- Anoxia
Properties of oxygen?
- Colourless
- Tasteless
- Odourless
Properties of carbon monoxide?
- Colourless
- Tasteless
- Extremely hazardous due to its insidious nature
What are the following altitudes:
- Cabin pressure set to?
- When 100% oxygen is required?
- When 100% oxygen is required under pressure?
8,000 ft
34,000 ft
40,000 ft
What is the altitude at 18,000 ft compared to sea level?
The atmospheric pressure at 18,000 f is about half of that present at Mean Sea Level (MSL). The partial pressure of oxygen at 18,000 f is about half the normal intake.
2 common types of regulators?
- Continuous flow
- Demand
Continuous flow regulators are able to vary the oxygen flow with changes in altitude, this is achieved in 2 ways, what are they?
- Manual
- Automatically
What are the disadvantages of continuous flow regulators?
Waste of oxygen - oxygen flows regardless of the whether the air crew are breathing in
Operation of the passenger service unit, when regarding continuous flow regulators?
- A trigger valve operates at about 14,000 ft cabin altitude (as might happen during decompression).
- Oxygen is fed from the trigger valve, through the continuous flow regulator to the overhead storage compartments. The oxygen pressure activates pressure latches, which allows the masks to fall from the overhead storage compartments.
- The action of the passenger pulling the mask down firmly opens a valve (Trigger valve), which supplies oxygen to the mask.
Explain dilute and demand regulators?
Dilution: Dilutes the oxygen with cabin air to provide the aircrew with a varying oxygen/air mixture. The ratio of oxygen-to-air depends upon the aircraft’s altitude.
Demand: The regulators supply the aircrew, whilst breathing in (demand), with the varying oxygen/air mixture diluter demand). When the aircrew are not breathing in, oxygen flow from the regulator stops.
Operation of dilute/demand regulators:
- What must occur for oxygen to flow into the first stage pressure reduction chamber?
With the regulator connected to the aircraft’s oxygen supply, oxygen pressure is felt at the pressure gauge and at the ON/OFF valve. Operating the supply control ever to “on’ will open the supply valve, allowing pressure into the first stage pressure reduction chamber and to the demand valve.
Operation of dilute/demand regulators:
- What happens in the cabin air chamber?
Cabin air mixes with the oxygen to make it useable by the aircrew
Operation of dilute / demand regulator:
- What happens to the diluter aneroid capsule when the aircraft reaches 34,000 ft?
The diluter aneroid expands, due to the increase altitude, this blocks the diluter assembly shut off valve and 100% oxygen flow is triggered
Operation of dilute / demand regulator?
- Why is the safety pressure feature incorporated? And how does it operate?
- Correct amount of oxygen (even with a leaking mask)
- Oxygen under pressure (breathing) in the event of a cabin decompression
100% oxygen supply is gradually overridden by the safety pressure valve, which is operated by the safety pressure aneroid capsule at 40,000 ft above which oxygen under pressure is supplied to the aircrew
2 types of oxygen masks?
- Continuous flow
- Demand
3 types of oxygen cylinders?
Extra high pressure - 3600 PSI - Black with white head
High pressure - 1800-2000 PSI - Green
Low pressure - 425-450 PSI - Yellow
PUB for safety precautions regarding dry breathing oxygen?
AAP 7002.023 (AM1) Dry Breathing Oxygen Technical Maintenance Requirements and General Information
PUB for cylinder life of oxygen bottles?
Relevant aircraft technical maintenance plan (TMP -7)
High pressure gaseous oxygen system:
- What is the purpose of the pressure reducing valve?
- What is the purpose of the line valve?
Reduces the pressure to a suitable pressure for the regulator.
Isolates the storage cylinder from the rest of the system. This allows for the removal of system components without having to remove or empty the cylinders.
High pressure oxygen:
- Make up of cylinders?
- Type of plumbing?
Cylinders are:
- Steel / high steel alloy
- Green
Plumbing:
- Stainless steel
Connecting fittings are silver soldered
Easy way to distinguish between the high and low pressure gaseous oxygen systems?
The low pressure system does not have the pressure reducing valve
