Abstract: A flushing method for a lubricating oil system includes a step of performing precedent inside oil flushing for bearing box, by connecting an oil supply pipe and a flushing apparatus mounted to a bearing box to each other by a bypass pipe while bypassing an internal pipe that is provided in the bearing box and introduces an oil supplied from the oil supply pipe to a part between a rotor of a turbine and a bearing, supplying the oil from the oil supply pipe to the flushing apparatus through the bypass pipe, and injecting the oil from the flushing apparatus into the bearing box, to thereby perform oil flushing for the inside of the bearing box; and a final oil flushing step of supplying the oil from the oil supply pipe to an internal pipe, to thereby perform oil flushing for the inside of the lubricating oil system, after the step of performing precedent inside oil flushing for bearing box.

Abstract: The present invention is intended to provide a method for assessing remaining lifespan of a bolt with higher precision than conventional methods, which can be applied to a bolt comprising a high alloy with fewer tissue changes caused by creep damage. The present invention provides a method for assessing the remaining lifespan of a bolt used at high temperatures, including: carrying out a creep test for a bolt material that constitutes a bolt to be assessed and determining a life-time and a life-elongation rate; determining a time-temperature parameter based on the life-time and the creep test temperature; creating a lifespan-assessment diagram by plotting the time-temperature parameter with respect to the life-elongation rate; measuring a elongation rate between before and after the use of the bolt to be assessed; and assessing the remaining lifespan of the bolt with the use of the elongation rate between before and after the use of the bolt to be assessed and the lifespan-assessment diagram.

Abstract: The present invention is intended to provide a method for assessing remaining lifespan of a bolt with higher precision than conventional methods, which can be applied to a bolt comprising a high alloy with fewer tissue changes caused by creep damage. The present invention provides a method for assessing the remaining lifespan of a bolt used at high temperatures, including: carrying out a creep test for a bolt material that constitutes a bolt to be assessed and determining a life-time and a life-elongation rate; determining a time-temperature parameter based on the life-time and the creep test temperature; creating a lifespan-assessment diagram by plotting the time-temperature parameter with respect to the life-elongation rate; measuring a elongation rate between before and after the use of the bolt to be assessed; and assessing the remaining lifespan of the bolt with the use of the elongation rate between before and after the use of the bolt to be assessed and the lifespan-assessment diagram.