As outlined in our operations manual based on Boeing procedures (AD 2002-19-52 etc.) During climb or cruise set one centre tank fuel pump to off when centre tank fuel quantity reaches 950kg. Open crossfeed valve to minimise imbalance. Set remaining center tank pump to off and close crossfeed valve when MC and Fuel annunciator light iluminates. All dating back to the Thai explosion in BKK. Mod to avoid this being rolled out but procedure still in place.