TM 1-1520-238-10 2-37 N₂ INERTING UNIT AIR VENT AND FUEL PRESSURE RELIEF VALVE AIR, FUEL TRANSFER CONTROL VALVE AIR PRESSURE IN FUEL TRANSFER SHUTOFF VALVE AIR PRESSURE IN TO APU FIREWALL TO NO. 2 ENGINE RIGHT CROSSFEED SHUTOFF VALVE TO LEFT CROSSFEED SHUTOFF VALVE FUEL TRANSFER PUMP FUEL PRESSURE SWITCH PILOT VALVE FUEL QUANTITY XMTR BOOST PUMP SHUTOFF VALVE AFT FUEL CELL 4-WAY FUEL SUPPLY CHECK VALVE SUMP DRAIN VALVE OVERBOARD DRAIN LOW LEVEL SENSOR OVERBOARD VENT N₂ TO FWD FUEL CELL M01-040-2 APU FUEL SHUTOFF VALVE TO FORWARD FUEL CELL GRAVITY FILLER PORT APU FUEL BOOSTER PUMP FUEL BOOST PUMP PULLAWAY COUPLINGS EXTERNAL FUEL TANK (S) RIGHT SIDE EXTERNAL FUEL TRANSFER SHUTOFF VALVE WING JOINT FUEL SHUTOFF VALVE AIR PRESSURE IN EXTERNAL FUEL TANK SHUTOFF VALVE TO LEFT EXTERNAL FUEL TANK(S) EXTERNAL TANK CHECK VALVE Figure 2-23. Fuel System (Sheet 1 of 2)