Is a double-flange differential pressure level gauge suitable for situations with large variations in system pressure?
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Liquid level measurement in the gas-liquid separator: the measurement range is 3 m; the density of the liquid phase is 1.02, and the temperature is around 70°C. The normal operating pressure is 7 MPa. The pressure in the gas phase is regulated using control valves, which results in some fluctuations in pressure. Additionally, when the pressure needs to be increased, the pressure variation can be significant. Is a double-flange level gauge suitable? Please discuss its advantages and disadvantages. Have there been any successful cases of using other level gauges in similar operating conditions?
The advantage of double-flange level gauges is that no anti-freezing measures are required
Special attention must be paid to preventing freezing in double-flange designs! ! !
Double-flange designs are not suitable for such environments; a regular differential pressure transmitter can be used for measurement. An isolator should be installed at the point where pressure is taken – it is best to use an isolating fluid such as water or ethylene glycol, any fluid that does not react with the medium and has stable physical and chemical properties. The pressure conduit leads to the differential pressure transmitter, where the pressure is measured to determine the liquid level
What I want to ask is not about the advantages and disadvantages of double flanges, but rather those in this type of application; it can also be understood as what problems might arise under such conditions: lol. But thanks for your reply
My understanding is that with a double-flange level gauge, pressure fluctuations occur when there are changes in pressure; after all, when a control valve is used to regulate pressure at such high levels, fluctuations within 0.2 MPa are still possible. But it cannot be confirmed either. But ordinary differential pressure level gauges definitely won’t work; the operating conditions are not suitable, and the high pressure leads to many leakage points, which is not appropriate.
Under alternating high pressure changes, the diaphragm will fail prematurely.
Not suitable? Why is it not suitable?
The following are my personal opinions: 1. Can a float-type level gauge be used for measurement? 2. When using double flanges for measurement, can a bypass device be considered, with the double flanges installed on this bypass? 3. Ordinary differential pressure transmitters can be welded using socket welding, and there will be no leakage issues (they can also be used in units where the pressure reaches 40 MPa, such as synthesis units and hydrogenation units). Thank you
I have two considerations. First, this is a gas-liquid separation process, with temperatures of seventy or eighty degrees; the pressure guide pipe in the gas phase might experience condensation and liquid accumulation； Secondly, the pressure guide tube and the pressure transmitter are connected using butt-welded terminal fittings; fear that over time, thermal expansion and contraction may cause the screws to loosen and lead to leaks.
1. This is a good idea； 2. If the equipment has an outlet, why is a bypass device added? What’s the reason behind this? Adding flange connections increases the number of leakage points. 3. The terminal connectors are connected by threads, and there is a risk of leakage over time.