BG4 Flashcards
What is the purpose of the pneumatic system in the context of oxygen distribution?
The pneumatic system is responsible for the oxygen distribution to the breathing loop.
List the components of the pneumatic system.
- O2 Cylinder
- O2 Pressure Reducer
- Minimum (Demand) Valve
- O2 Lines
What is the volume of the O2 cylinder used in the BG4?
Two litres.
What materials can the O2 cylinder be constructed from?
- High-grade alloy-steel
- Carbon composite
What is the pressure of a fully charged O2 cylinder?
About 200 bar.
How much oxygen does a fully charged O2 cylinder contain?
At least 400 litres of 99 per cent O2.
Under normal breathing conditions, how long is the O2 cylinder rated to last?
Four hours.
What is the function of the brass On/Off valve on the O2 cylinder?
To control the flow of oxygen from the cylinder.
What safety feature is included in the On/Off valve to prevent over-pressurization?
A safety cap that will burst at about 275 bar.
True or False: Cylinder valves should be opened quickly to prevent oxygen burn out.
False
How often must steel cylinders be hydrostatically tested?
Every five years.
To what pressure must steel cylinders be tested to comply with regulations?
345 bar.
What is the volume of the O2 cylinder?
Two litres
What materials are the O2 cylinders available in?
High-grade alloy-steel or carbon composite
What is the pressure of a fully charged O2 cylinder?
About 200 bar
How much oxygen does the cylinder contain?
At least 400 litres of 99 per cent O2
How long is the O2 cylinder rated to last under normal breathing conditions?
Four hours
What type of valve is equipped on each cylinder?
Brass On/Off valve
What safety feature prevents over-pressurization in the O2 cylinder?
A safety cap that will burst at about 275 bar
Why should cylinder valves be opened slowly?
To prevent oxygen burn out
How often must steel cylinders be hydrostatically tested?
Every five years
What pressure must steel cylinders be tested to during hydrostatic testing?
345 bar
True or False: The O2 cylinder is secured to the BG4 frame using a pull strap and buckle.
True
Fill in the blank: A fully charged O2 cylinder contains at least _______ litres of 99 per cent O2.
400
What is the primary function of the O2 pressure reducer in the BG4?
Distributes high and medium pressure O2 to the breathing loop
The O2 pressure reducer is crucial for managing oxygen delivery during operation.
What activates the electronics of the O2 pressure reducer?
High pressure from the O2 cylinder
This activation is essential for the functioning of the pressure reducer.
What is the output pressure range of the O2 pressure reducer?
4.0 bar to 4.4 bar
This medium pressure output is vital for supplying O2 to the breathing loop.
At what pressure does the relief valve activate to prevent over pressurization?
6.0 bar
The relief valve is a safety feature to avoid excessive pressure in the system.
What is the rate at which O2 is replaced in the breathing loop during normal operation?
1.5 to 1.9 L/min
This constant dosage is necessary to maintain adequate oxygen levels.
What flow rate of medium pressure O2 is supplied when the minimum (demand) valve is activated?
80 L/min
This high flow rate ensures that the user receives sufficient oxygen on demand.
What is the flow rate of O2 injected into the breathing loop by the manually operated by-pass valve?
50 L/min
This manually controlled feature allows for additional oxygen supply when needed.
How is the O2 pressure reducer connected to the O2 cylinder?
By a hand-tightened connector
This design facilitates easy assembly and disassembly for maintenance.
What is the function of the minimum (demand) valve?
To inject additional O2 into the breathing loop during extreme physical effort.
Where is the minimum valve located?
On the right side of the breathing bag.
At what pressure range does the minimum valve activate?
When the breathing loop pressure drops to between 0.1 and 2.5 mbar.
What triggers the activation of the minimum valve?
Deflation of the breathing bag, which activates the valve’s rocker arm.
What causes a pressure drop in the breathing loop?
Excessive breathing demand or a leak in the system.
What type of O2 does the minimum valve use?
Medium pressure O2 from the O2 pressure reducer.
How much O2 does the minimum valve provide to the breathing loop?
Approximately 80 L/min.
What is the purpose of the COz scrubber canister in the BG4 breathing loop?
Removes carbon dioxide from exhaled air
This is essential for maintaining breathable air during prolonged use.
How is inhaled air treated in the BG4 system?
Cooled by the air cooler and replenished with O2
This process ensures that the air is suitable for breathing.
What are the main components of the BG4 breathing loop?
- Facemask
- Connector assembly
- Exhalation/inhalation hoses
- COz scrubber canister
- Breathing bag
- Pressure relief valve
- Moisture relief valve
- Air cooler
Each component plays a crucial role in the effectiveness of the breathing system.
True or False: The BG4 breathing loop operates in an open system.
False
The BG4 operates in a closed breathing loop.
Fill in the blank: The _______ is used to manage excess pressure in the BG4 breathing loop.
Pressure relief valve
This valve prevents overpressure situations that can occur during breathing.
What is the function of the moisture relief valve in the BG4 system?
Removes excess moisture from the breathing loop
This is important to prevent condensation that could affect the system.
What role does the breathing bag serve in the BG4 breathing loop?
Acts as a reservoir for inhaled air
This allows for a consistent supply of air to the user.
