The idea is to take a piece of line about a 1/4" long and put over the outside of the line where it connects. That line be it Tygon, Silicone or any other material will never come in contact with the fuel so it will not soften and get loose like the line itself. I have a pair of forceps that work perfect for stretching the piece of line over the line itself then just take the doubled up line end and push it on the fitting. The giant scale racers have been using this trick for years and pulling some huge g forces without loosing a line. I have never had one leak since going this route. I have tried mechanics wire and had it actually cut the line.