Steam generators not subject to inspection – the location of the water-steam interface, tube wall corrosion issues
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In steam generators that are not subject to inspection, the location where steam and water separate is where corrosion is most severe. Since no inspection is carried out, the water volume inside the unit must be kept within 30 liters; as a result, the heating tubes are necessarily of small diameter. According to clause 7.5.1 of GB/T16508.3, when calculating based on the riser tube (at the vapor-water interface), the additional thickness increases from 2 mm to 4 mm; therefore, for the heating tubes of evaporators that are not subject to inspection, the wall thickness must increase as well. This question is quite confusing; everyone is welcome to discuss it.
The steam generator is no longer subject to inspection, and the additional wall thickness of the pipes certainly won’t be determined in accordance with GB/T16508
This is caused by oxygen corrosion. Considering increasing the wall thickness will only delay the service life a little; it actually isn’t very effective. I suggest you consider the water quality.
Using a blast tube is not appropriate, as the pressure-bearing conditions are different.
What does it mean when the pressure conditions are not consistent? Same pressure, just different volumes
Agree with the 4th floor. A steam generator without a drum is a direct-flow forced-circulation boiler, and the water quality must meet the requirements of direct-flow boilers.
Can a pipe with a thickness of around 3 millimeters be used at the vapor-water interface?