What system I use depends on the plane and make of tank. Most the engines I use are a closed pressurized system and I can use just a Tee fitting to run out a fill line through a fuel dot and for the pressure relief line or over fill. One thing that wasn't mentioned was the fuel filter John is using on his YAK to attach the two lines. How good of an idea is that!!! I don't care for the two part filters, had one come apart from vibration once, but I do install the crap trap filter inside my fuel tanks on the main line. I can't recall the last time I had any crud or dirt in one of my fuel regulators. Filters are a good idea!!
Mater of fact, I forgot to install one in the engine I worked on yesterday when I put it back in the plane. I will go out now and install one. Surprise, it will be a two piece like John is using. I just happen to have a bunch of them on hand. Just because I don't care for something doesn't mean I don't use them!!
