HP And LP Air Flashcards
Why is HP air used onboard?
It can easily be distributed around the ship
Can be easily stored
Low risk of fire
Very flexible
Six services that use HP air
Diesel generator starting
Gas turbine starting
Ship siren operation
Weapons systems operation
Breathing apparatus charging
Air driven machinery operation
Where is HP air used on board
Inside machinery space
Outside machinery space
What is HP air operating pressure
276 bar
When will relief valves operate
If there could be damage to the hpac and when it needs to relive excess pressure
What are the 4 stage pressures of HPAC
Stage 1 - 4 bar
Stage 2 - 17.5 bar
Stage 3 - 68 bar
Stage 4 - 276 bar
Purpose of the HPAC drain and separators and how often do they operate?
Drain- to blow down any oil or moisture into the bilge and every 30 minutes
Separators - trays at the bottom of HP compressors to collect any water and when the valve is open
What pressure do safety jackets operate at and what is it protecting?
3.5 bar and the cooling system
What is the LP operating pressure?
8 bar
4 services that use LP air
Pneumatic tools
Radar wave guides
Emergency stern seal inflation
Pneumatic surveillance panels
PPE when changing air bottles
Goggles and air defenders
