The pressure rises after the pump is stopped in the inlet pipeline of the loading pump, reaching up to 2.9 MPa
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Dear teachers: I have encountered a problem recently. The pipeline for the loading pump in our company runs directly from the tank area to the loading pump; its length is approximately 200 meters, with no branches along the way. The medium flowing through this pipeline is octanol； Pump outlet to loading arm ； But recently, when the pipeline is not in use, the inlet and outlet flanges often leak due to pressure buildup; the pressure gauges with a range of 2.5 MPa have been damaged as well. There is high pressure inside the pipeline, and it lacks insulation, heating, as well as any means for introducing air ； I suspect it’s thermal expansion and contraction in winter, but there’s no reasonable explanation for the high pressure; please help analyze it.
It’s best to check whether the feed valve has internal leakage. For this type of control, it is best to install two valves, with a hydraulic valve placed between them. After closing two more valves, keeping this valve in the open position is one of the methods to prevent the pipeline from overpressuring. If there is material leakage, it can be detected by appearance. Check whether this pressure is approximately equal to or the same as the discharge pressure of the material production unit; this is also the source of the overpressure. Based on the physical and chemical properties of the material, there is little possibility of overpressure if there is external pressure present. For reference.
It’s inevitable! The pipeline is filled with the liquid phase, and the valves at both ends are closed. As the temperature rises, the volume of the liquid increases, which can lead to extremely high pressures; however, if there is a leak in the valves, the pressure will not rise. It is recommended to add a vent line at an appropriate location at the lowest point of the pipeline, or to slightly open the pump inlet and outlet valves periodically to relieve pressure in the large tank.
I’ve encountered the same problem before as well; I don’t know the reason. Mine is a pressure transducer tube for measuring differential pressure.
This situation is also observed in our methanol pumps. During the summer, air pockets occasionally form in the pipeline from the pump to the intermediate tank; these air pockets disappear once the inlet valve of the pump is opened after methanol has been pumped out. This indicates that there is a phenomenon of pressure buildup due to gasification in the pipelines during the summer. But it’s incomprehensible that this happens to you in winter.
In winter, the temperatures are low, so even if the pipelines are sealed, overpressure is not possible. Organize the pipeline process – could it be pressure coming from somewhere else? “What is the state when it’s not in use, and which valves are activated?
Organize the pipeline process – could there be pressure leakage elsewhere?
Direct pipeline, no branches; voltage stacking is impossible
In winter, it is now suspected that the large temperature differences between day and night, along with thermal expansion and contraction, are the cause, but no theoretical evidence to support this has been found
Hello, may I ask what factors, in theory, could cause such a high increase in pressure within this pipeline? I have seen many installations before and such a situation has never occurred there; it’s only happened recently. Is this related to the properties of the material?