There are 3 pipes that connect to the fuel pump hanger. Im guessing one is for fuel delivery the other is for fuel return but not sure what the 3rd one is for? Can anyone enlighten me.
Breather line sends the tank fumes to the charcoal filter canister on the bulkhead. This filters the fumes and makes them safer. It vents to atmosphere.
Although bear in mind that until the fumes have gone through the filter they would be regarded as flammable/hazardous so a leak in the pipe is not advisable.