Cabin Pressurization Servicing an Oxygen System Fill chart

Cabin Pressurization

Servicing an Oxygen System

Fill chart for Oxygen

Pressurization Terms ► Absolute Pressure – Pressure measured along a scale which has a zero value at complete vacuum. ► Absolute Temperature – Temperature measured along a scale which has zero value at that point where there is no molecular motion (-273. 1 C or -459. 6 F) ► Aircraft Altitude – The actual height above sea level at which an aircraft is flying.

► Cabin Altitude – Used to express cabin pressure in terms of equivalent altitude above sea level. ► Differential pressure – The difference in pressure between the pressure acting on one side of a wall and the pressure acting on the other side of a wall. In aircraft pressurization systems, this is the difference between cabin pressure and atmospheric pressure. ► Gage Pressure – A measure of the pressure in a vessel, container or line as compared to atmospheric pressure.

Pressurization System Requirements… ►A source of compressed air for pressurization and ventilation ► A means of controlling cabin pressure by regulating the outflow of air from the cabin ► A method of limiting the maximum pressure differential to which the cabin pressurization area will be subject ► The areas of the aircraft subject to pressurization must be sealed to reduce inadvertent leakage.

Sources of Cabin Pressure ► Reciprocating engine aircraft § Positive-displacement Cabin Compressors § Roots Compressor – Rotors in an airtight casting § Vane Type Compressor – § Reciprocating Compressors – § Centrifugal Cabin Compressors -

Turbine Engine Aircraft

Cabin Pressure Control