ORIGINAL: Ed Smith
...They fill, feed and empty just the same as any other three line tank. Whether the pump used to fill is hand or electric there is no more danger of bursting one of these than there is of any other tank. Fuel will pour out of the overflow when the tank is full. The overflow has to be plugged when the tank is full...
Thanks, that's what I needed to know (third line for overflow).
Still, it doesn't sound "like any other tank", even for a three line tank. A regular three line setup gets filled via the fill line and overflow comes out the muffler line when it's full. The carb line stays connected all the time and the fill line gets plugged for flight. With the Tettra, it sounds like you fill through the carb line and watch for overflow out the overflow line, leaving the muffler line connected all the time and plugging the overflow line for flight.