1. - this system is used to combat fires engine nacelles and specific equipment compartments.
    Fire Extinguishing
  2. - will extinguish fire by displacing the oxygen from the fire area. 

    - used in some acft are of two types: bromchloromethane, “ CB” & dibroodifluoromethane, “DB”.
    Liquid Agents
  3. + usually spherical shape. 
    + made of stainless steel
    + holds a certain amount of liquid agent 
    (by weights & a charge of gas nitrogen by pressure.
    Liquid Agent Containers & Associated Components -
  4. - Indicates the internal pas nitrogen charge (pressure).
    Pressure Gage
  5. - is installed on the container to detect low pressure. 

    + when nitrogen pressure drops 225 psi or below
    + the pressure switch contacts will turn on a warning light in the FLT deck. 

    + one per container (Fire Bottle)
    Low Pressure Switch
  6. - protects the container from over pressurizing due to thermal expansion. 

    + the fusible plug, in the thermal relief valve,will melt when the temperature of the liquid in the container reaches 200 to 250 degrees F. - releasing contents of container (overboard) 

    + fusible plugs acts as a safety device 
    + contents are route thru tubing to a red indicator disc.
    Thermal Relief Valve Device
  7. - {directs the flow of liquid agent} from the container and houses the discharge squib/cartridge and screen housing.

    + number will depend on acft. 
    + where component are counted (housed)
    Discharge Valve/Head
  8. - to rupture the post. 

    + takes [fired by] 28 VDC to fire the squib. 
    + is an explosive device that must be handled carefully. 
    + Always called a “Squib”.
    Discharge Squib/Cartridge
  9. - secures the screen housing and squib/cartridge to the discharge valve/head. 

    + Provides a means of attaching squib to discharge valve/head.
    + holds the screen housing inside the discharge valve.
    Retainer Nut
  10. - installed between the retainer nut & the discharge valve to prevent leaks when the container is discharged. 

    + acts as a seal between retainer nut.
    Retainer Nut O-Ring
  11. - contains the screen and is used to attach the discharge valve/head to the container. 

    + holds screen in place. 
    +provides a method of attaching the discharge valve to the container.
    Screen Housing
  12. - this seal prevents leakage between the discharge valve and the container when the container is discharged.
    Screen Housing O-ring
  13. - catches the post segments and the plug to prevent clogging of the tubing which may obstruct the flow of agent.
  14. - holds the plug in place & is ruptured when the squib is fired. 

    + pressure inside the container will then push the plug out. 
    + Removing the contents from container.
  15. - holds the agent & nitrogen pressure in the container.
  16. - seals between the plug & container to prevent leaks when the container is full & pressurized.
    Plug O-Ring
  17. - directs the flow of agent to the two-way check valve. 

    + located on the container.
    Discharge Valve/Head
  18. - is pressure operated and spring  loaded to one position to prevent movement and vibration during FLT. 

    + to prevent a full container from emptying into a container that has already been discharged. 
    - after the agent does thru the check valve, it does through tubing until it reaches the nacelle discharge outlets. 
    + AKA Double Tee Check Valve.
    Two-Way Check Valve
  19. - located in the engine compartment. 


    + when agent leaves the discharge outlets, it will blanket the outside of the engine & put out the fire. 

    -  located @ top of engine compartment. 

    + outlets are located in the zone two compartment of the engine. 

    - sprays a mist of agent over zone two compartment (body) of engine.
    + connected to the two-way check valve by turbine.
    Nacelle Discharge Nozzles
  20. - Emergency control handle (T-handle) is pulled to start the emergency shutdown procedure. 
    + Located on the engine Fire Emergency Control Panel. 
    - Each Handle controls a specific engine.
    Isolation Circuit
  21. + fuel (mechanically & electrically), bleed air, hydraulic fluid & cooling air to that engine. 

    + T-handle is pulled to gain access to the actual discharge SW. 

    Set Bottle Selector SW - 2 POS [NORMAL & ALTERNATE]
    When handle is pulled, it shuts off: (ISOLATION CIRCUIT)
  22. - Located behind control handle T-handle
    + when pushed, sends 28 VDC to discharge squib.
    Push Discharge SW/ Button
  23. + Discharge valve head
    - Check Valves
    + Nacelle Discharge Valve
    - Zone 2 of Engine Compartment.
    Liquid Agent Flows To:
  24. 1) Fuel Electrically & Manually 
    2) Bleed Air
    3) Cooling Air
    4) Hydraulics
    Pulling “T” Handle
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