The Viking engine has two fuel injection pumps, a primary and a backup. First the fuel flows from the header tank to a T fitting (to be installed later) where the fuel is split into two lines. The gas from each line has a low pressure filter to go through before it hits the pumps. From the pump it goes into a distribution block where it can either go to the engine, get monitored by the fuel pressure sensor (for the avionics), or return to the header tank via a blowoff valve. All this is mounted below the passenger seat except for the low pressure filters which are mounted below the header tank for easy access.