Issues related to medium treatment in process pipelines
Thread Content
The process conditions are as follows: For oil and gas pipelines with a DN150 diameter, pressure testing is carried out before restarting operation. Due to the long length of the pipelines and some unreasonable design aspects, some water remains after the pressure testing. Since the pipelines have not been restarted, there is residual oil inside them, making it impossible to directly open the pipelines for draining water from the lowest points. Is there any good way to remove this water from the lowest points so that nitrogen can be used to purge the pipelines? There are currently the following options: 1. Steam at 1.0 pressure is introduced at one end of the pipeline and discharged from the other end, using the steam to carry the water out. 2. The pipeline is disconnected near the valve, inserted back into the pipeline, and connected to a pneumatic diaphragm pump for extraction; however, many substances still remain unable to be extracted. Are there any other good ways?
It’s good to disconnect the pipe, insert a hose and draw out the water. As for the remaining water, it’s advisable to dilute it with a hydrophilic, volatile liquid such as alcohol before drawing it out, and finally, everything needs to be dried.
Is a pressure test conducted if there is residual oil?
Since the entire unit failed during its first startup attempt, operations were halted for half a year. Although the material was removed, residues remained on the pipe walls; therefore, hydrostatic testing was carried out directly in order to keep the project on schedule
But the device doesn’t have hot nitrogen – where does this hot nitrogen come from?
But adding alcohol introduces new impurities
Alcohol evaporates easily and can be blown away by air. For many of our items, we first wash them with water and then dry them with alcohol, which allows for quick drying
Well, I haven’t tried it yet, but I think it should work. Thank you so much
To remove moisture from the pipeline, instrument air can be supplied continuously; the acceptance criterion is that the dew points at the inlet and outlet are identical.
A small amount of water is fine; but if there are hundreds of kilograms of water in the pipe, how many months would it take to blow it dry?