What is the hot tightening temperature at the start-up of the device?
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What is the hot tightening temperature at the start-up of the device? Who knows
After the equipment has been in operation for some time, this occurs due to the thermal expansion of the bolts. Loosening can easily lead to leaks and other issues, so it needs to be tightened with heat, but not so tightly that it may cause bolt fatigue or slippage – adjust the tension as appropriate. Hehe-----. If there is anything wrong, please correct me, senior.
In simple terms, it means that the equipment should be tightened once its temperature reaches a certain level. After maintenance is completed and testing for leaks has been done before starting up, components such as manholes need to be tightened while they are still hot. For example, in a atmospheric pressure tower where the temperature at the bottom of the tower is 365 degrees, tightening should be carried out at around 200 degrees. In a regenerator where the temperature is 710 degrees, manholes need to be tightened at around 350 degrees. I haven’t been involved in the process of tightening components while they are hot, but this is roughly how it is done. Please feel free to correct me if I’m wrong
Hot tightening of a plant refers to the process of tightening bolts and other fasteners that were tightened at normal temperature due to the high operating temperatures of the plant; as the temperature rises, factors such as thermal expansion cause some of these fasteners to loosen, so hot tightening is necessary. The temperature at which this tightening is carried out is known as the hot tightening temperature.
When the temperature of equipment such as reactors and heat exchangers rises, it causes thermal expansion of the pipes. Due to the difference in expansion coefficients between the pipes and the bolts, the flange connection bolts that were tightened at normal temperatures become loose. To ensure the sealing effect of the gaskets at the flange, it is necessary to tighten the connection bolts again while they are heated—thermal tightening. Experience has shown that hot tightening is most appropriate when carried out after maintaining a constant temperature of 250°C for 2 hours.
I agree with what was said on floor 5: any device must undergo thermal tightening during its commissioning process after new construction or maintenance work.
It is recommended to heat-tighten devices or equipment operating at temperatures above 200 degrees