Questions regarding the liquid level gauge installation diagram

This pipeline can protect the instrument diaphragm when the root valve is closed to disconnect the instrument

Is it possible that it was designed for on-site level gauges? Such as flap switches, or glass tube level gauges

This post was last edited by Hariky on 2017-10-11 at 16:22. I’ve never seen such an installation either; it’s not included in the HG installation manuals. Let’s make some assumptions for discussion. It should be a condition where condensation occurs easily in the gas phase; it’s not clear what the state of the liquid phase is (it’s unclear why a condenser is also installed on the high-pressure side). The advantage of this connecting pipeline is that it can eliminate in real time the pressure difference between the high-pressure and low-pressure sides caused by the gas-phase static pressure of the equipment. The isolation valves are closed one by one; if the valves are not closed in a timely manner under conditions of high static pressure, the transmitter may experience sudden changes in pressure difference. Note: I really have never seen such a design. It seems to be the design of a foreign company; could you also post the material list below the hook-up diagram?

This post was last edited by feng*aosa on 2017-10-11 21:48. This is a compensation tube that can, to a certain extent, offset measurement errors caused by changes in the density of the medium due to temperature variations. 　　When changes in the internal temperature of the device cause changes in the density of the medium, the compensation tube, being outside the device, experiences only minor temperature changes. 　　Differential measurement detects the liquid level of the compensation tube, which may not correspond to the actual liquid level inside the tank. 　　In principle, differential pressure and float-type level gauges measure the \"volume\" of the medium, while float and radar-type level gauges measure the \"surface\" of the medium. When the measurement of \"quantity\" is more important, it is said that installing a compensation tube can improve measurement accuracy. 　　Such compensation tubes are installed in level measurements where density is greatly affected by temperature and it is necessary to calculate the weight of the medium inside the tank (such as liquefied petroleum gas). 　　For a deeper understanding of the principle, refer to the dual-chamber balance vessel used in boiler level gauges.

It may be used to measure high-temperature media, forming a U-tube with the container to enable indirect measurement

Well, that makes sense. Thank you! I’ve learned it! :victory:

Your eye for detail is amazing! :Lol, this project is indeed an overseas project. This is rarely done in China; it’s an oil refining project. It’s not clear whether it was the client’s requirement or what else led to this, but all liquid level measurement installations are set up in this way.

There are no valves on the pipe; I don’t understand it