Can you explain what the 4 lines inside of an I30 gas tank do?

Question

I am attempting to clear a 1491 code.  I replaced almost all involved components with no change. The fuel filler neck assembly has 4 lines that run to the fuel tank.  3 are clear and one appears to be clogged.  A similar tank in the junk yard is exactly the same. This makes me think that this is normal.   I would like to know what those lines inside of the tank do. This would let me know if this is normal or not.

Answer 1

P1491 that the vacuum cut valve bypass

Check the charcoal canister shake it, if there is a rattle noise the canister fell apart internally. This code is for the vacuum cut valve bypass. The lione that is important and must be clear is the from the  vacuum cut valve and the fuel tank. and the vacuum cut valve to the evap cansiter