A boiler for pyrolysis of diesel oil using remaining heat was investigated.Three geometry models on the gas collection tube of the boiler with initial defects were built up based on the NDT data.The effect of damage to the ability of enduring loads of the tube was taken into account by the way of FEA.By applying the rules of ASME Ⅷ and of JB4732-95 standard,some prediction and discussion about the defect effects to the equipment in the engineering was made.
