Can anyone tell me what this hose (in the first two pictures) is used for? Upon cleaning the tank, I removed little rubber particles that looked like they came off of something. I'm thinking it's from this hose. The end of it looks to be in rough shape as if a piece (or pieces) broke off. The tank is currently primed and ready for its paint job. Now I'm just curious to know what the function of this hose is for.
Since i'm inside the tank, what is the piece that the red arrow is pointing to?