Damage assessment and maintenance strategy of hydrogen reformer furnace tubes

The states of damage along a reformer tube in service for 10 years are meta llographically analyzed. Damage levels are ranked relating to remaining lif e. The damage distribution is obtained for the whole reformer tube. The res ults show that the accumulated damage of the tube is non-uniform. The damag e level in the lower part of the reformer tube is significantly higher than that in the upper part, especially in the weld region. The damage localiza tion is also verified by use of a continuum damage mechanics finite element technique. Accordingly it is proposed that local replacement might be a de sirable method to extend the service life when the lower part of the reform er tube reaches the safe rupture life, (C) 1999 Elsevier Science Ltd. All r ights reserved.