Problem of gauge fluctuation during pressure boosting of storage tanks in LNG refueling stations
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When the storage tank of the LNG refueling station is pressurized, fluctuations occur in the level gauge; the pointer of the gauge drops by 100–200 units. Once the pressurization is complete, the level and pressure return to normal. Is this phenomenon normal? The pressurization method involves feeding liquid from the bottom to achieve saturated pressurization. Are there any ways to reduce such fluctuations? I turn to the all-powerful forum for help, {:2_40:}
Positive pressure in the pipe may cause liquid to flow out; it is recommended to use a gas source with pressure equal to or higher than that of the pipe to perform backwashing. This is likely due to the liquid in the pipe vaporizing as a result of the positive pressure. (For reference)
Thank you. Do you mean the liquid phase tube of the level gauge by positive pressure tank?
As a supplementary note, the gauge pointer does not move at any other time except when pressure is being increased
This post was last edited by CHANGBAISHI on 2018-10-24 at 11:26. Yes, the positive pressure tube of a level gauge is the sampling tube located below the liquid tank. It is estimated that there are issues with minor leaks or insulation, which cause the liquid to gradually move outward in the positive-pressure tube; when it comes into contact with heat, it vaporizes. As pressure increases, the location of the liquid shifts backward, and it vaporizes again, causing it to shift further backward, over and over again – which results in fluctuations. This is just one of the common causes of fluctuations.
Fluctuations in liquid level caused by pressure fluctuations are normal; as long as the liquid level stabilizes once the pressure is stable, there is no problem
I heard that the fluctuations in saturation level and boost pressure should be more significant – is that true? Please advise: handshake
That was the level fluctuation caused by the vaporization of the liquid
After reading the reply, I feel I’ve learned a lot. Thank you, Haiyou, and thank you, Haichuan
{:1_90:}Thank you all for your help. I also want to know whether this fluctuation is considered significant; I was wondering if there are any people on the forum with relevant experience who could kindly provide an answer