Compensator in the condensate water pipline of a 300 MW power station unit was continually deformed into cracks.At the same time

supports and hangers of the pipline were draged inclined

and end cap of the heat well connected with the condenate water pipline was also deformed observably.Such a situtation would lead to accident of the power units.To solve this problem

stressing model of the entrance pipline of condensate water was estabilished.Moreover

load on the pipline

its stress and displacement

and also the endpoint thrust were calculated.Results show that

the basic reason for the problems mentioned above is not considering the inner pressure of the medium in pipeline design which will cause the extension of compensator along its axis direction.Suggestion that appropriate measures should be adopted to eliminate the effect of inner pressure of pipeline on the compensator when the pipeline with compensator is designed is given.