The unit is brought online; bolts are tightened thermally
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The unit is in operation – what temperature is required for hot tightening of the bolts, and are there any requirements regarding the pressure inside the pipes? Are there any standards I can check?
What I experience is usually around 80 degrees once, and 200 degrees once
The temperature rises; about 100 times per occurrence, and once more after it returns to normal
According to the standards, heat tightening should be carried out at a constant temperature of 250°C. However, in practice, if there are no obvious leaks after the furnace temperature rises, it is not necessary to perform heat tightening on all the flanges on site; it is sufficient to pay attention to the flanges in areas exposed to high temperatures, such as the flanges at the outlets of the radiation chambers of the two furnaces.
Once at 250°C, once at 350°C
The normal operating temperature of our device is around 250°C; therefore, during the trial operation, the temperature is raised to 150°C for one heat tightening session, and then raised to 250°C for a second heat tightening session
Previously it was done this way; now, unless a problem is detected, it’s generally not tightened. I feel uneasy just by looking at it, but production isn’t under my control so I can’t interfere. Even if I emphasize the issue, they just say it’s fine and that’s that; I can’t possibly do it myself