Fuel Pump Banjos

This type need a fibre washer, the threads start (arrowed) right from the face of the port:

This type need an O-ring, there is a recess in the face before the threads start:

Banjo and bolt with an O-ring on the pump side from Dave Dubois. Both types use a fibre washer on the bolt head side, which may have a recess as shown in this picture. This type may need a second fibre washer (logically the recess side) to prevent the banjo bolt bottoming in the pump and failing to apply sufficient pressure to the seal:

The banjo is recessed internally so fuel can flow round the bolt to get to the exit port, the two holes do not have to be in line: (MGOC)