Creep rupture is one of the most common failure modes of pipelines used in thermal power plants.Residual life prediction is an effective guarantee to ensure the safety

utilization and benefit maximization of equipment. Based on the creep rupture test data of 2.25Cr-lMo heat-resistant steel in actual service for over 200 000 hours

the selection principle of TTP parameters and its influence on the accuracy of life prediction are analyzed by comprehensively considering the working stress and TTP parameters. The relationship curve family of Z-parameter method is used to characterize the vertical dispersion of pipeline durability data in different power plants. The stress-TTP-reliability curve for evaluating the reliability of life prediction is established

and the relationship between the predicted life of different power plant pipelines and the working state of the unit is obtained.The creep residual life of different power plant samples at 540 ℃/45.26 MPa is 1.725 6×10~5 h and 3.378 8×10~5 h respectively

and the predicted reliability reaches 99%

which provide maintenance suggestions for the operation reliability of power plant equipment.