Abstract: In a turbojet fuel supply system in which a controlled flow of fuel ql is diverted from between the high pressure pump and the feed flow regulator and recycled upstream of the high pressure pump in order to maintain a substantially constant pressure differential cross the feed regulator, a flow qc is tapped from the hot flow ql for return to the fuel tank and to allow a correspondingly greater portion of cold fuel from the low pressure pump to be mixed with the recycled hot fuel ql delivered to the high pressure pump. If necessary, the tapped hot flow qc is mixed with a flow of cold fuel qf tapped from the low pressure pump output to form a lukewarm mixture qr for return to the tank.