How long does it take to pump fuel into the fuel tanks on a Boeing 747 plane.?

About 8 hours. The B747-200 had a fuel capacity of 330,000 lbs and used approximately 25,000 lbs per hour. The USAF E-4 Airborne Command Post is a highly modified B747-200 that has in-flight refueling capability and extra tank for engine oil and it can fly 3 days without landing.