• Joins a branch line to a main hydraulic supply to feed actuators or control valves during system repairs.
  
  

• Splits pneumatic supply air to feed two downstream valves or instruments in environmental and pressurization systems.
  
  

• Connects sensor or test ports to a common line on bench test rigs for simultaneous measurement or bleed checks.
  
  

• Provides a branch for cabin-service lines (water/air) in non-critical service areas where the AMM permits.

• What does this tee connect?

It joins or splits three tube/hose lines to route fluid or pneumatic flow where the aircraft data requires this exact part.

• Can it be used in fuel systems?

Only use the tee in fuel lines if the AMM and the CofC explicitly approve the part and material for fuel service. 

• How should I inspect it before fitting?

Verify part number and trace paperwork, check sealing faces and threads for nicks or deformation, and ensure ports are clean and burr-free.