Topic Discussion: Level Gauge Selection, Q&A Thread

Dear friends, I would like to ask: 1. How should one select instruments for measuring the oil-water interface? 2. How to select a level measuring instrument for media that tend to form foam?

I’ll answer the first question. A magnetic float level gauge can be selected. Different types of magnetic floats are selected based on the density of oil and water. Density difference greater than 150 KG/M3, temperature below 250 degrees, density > 400 KG/M3

I’ll answer the second question: By using a double-flange differential pressure transmitter for measurement, the foam in the container will not affect the level measurement.

When the pressure range of the container in which the level gauge is installed varies between slight positive pressure and negative pressure (for example, from a few kilopascals to minus 70 kilopascals), and the liquid medium is water, what type of level gauge should be chosen to enable on-site monitoring or remote signal transmission, as well as to accurately reflect changes in the liquid level?

Personally, I think differential pressure level gauges, radar sensors, servo systems, or magnetostrictive sensors would all work. As for the pressure changes you mentioned, I don’t think they have any impact on density; so any of these options should be suitable. Maybe the differential pressure level gauge will fall short?

1. For measuring the liquid level in crude oil and heavy oil storage tanks, non-contact methods (radar-based, ultrasonic) are preferred； For the level measurement of storage tanks containing light oils and chemical raw materials (non-corrosive), non-contact or contact methods (float type, differential pressure type) are recommended. 2. For on-site level indication in storage tanks, magnetic float level gauges or ball float level gauges are preferred; direct-reading colored glass plate level gauges can also be used. 3. For level measurement in dome tanks and floating roof tanks, a weight-type steel belt level gauge, a constant-force coil spring type steel belt level gauge, or a photoelectric level gauge is recommended. 4. For level measurement in internal floating roof tanks, external floating roof tanks, pressurized tanks, and storage tanks equipped with mixers or swirl devices, servo-level gauges installed with guide tubes should be used. 5. For the measurement of the liquid levels of crude oil, refined oil, asphalt, ethylene, propylene, liquefied petroleum gas, liquefied natural gas, and other fluids in large dome tanks and spherical tanks, radar level gauges can be used. 6. For measuring the liquid mass, density, volume, level, etc. of atmospheric pressure tanks, pressure tanks, dome tanks, and floating roof tanks, static pressure tank level gauges can be used; however, they are not suitable for measuring the level of highly viscous liquids.

TO: 2nd floor, for applications with foam, a radar level gauge can be used, as it allows the impact of foam to be ignored. TO: 5th Floor, the pressure fluctuations you mentioned can have an impact when differential pressure level measurement is used. The radar can meet your requirements and is also suitable for enclosed containers. Alternatively, magnetic flip plates can also meet your requirements. TO: 8th Floor. I heard from Siemens before that they acquired the world’s top-ranked level gauge. These three are not very different from each other, and I know them all.

Hello everyone, I’m a newcomer who just joined Haichuan. I’m asking questions right away and even posted a new thread! 　I’m sorry, please ask the moderator to delete it! I encountered a problem in practice: in a square tube with dimensions of 1m (200mm x 300mm), there is powder material inside the tube. Material keeps falling from above, while at the bottom there is a material transfer system (pneumatic conveying) that continuously removes the material. The requirement is that the tube should always contain material, and it is also necessary to know the location of the material within the tube. At first, we installed one level gauge each on the upper and lower sides of the material viewing area; these were of the fork-type. Later, vibration rod-type level gauges were used as well, and both types worked fine. However, it was not possible to determine the exact position of the material, so another level gauge was added, bringing the total to three. But the effect remains the same. I really hope to find a suitable material level measurement method that would allow me to adjust the discharge speed of the lower discharger based on the specific location of the material level, thereby reducing the fluctuations in the material level within the pipeline!

1. How should instruments for measuring the oil-water interface be selected? It depends on whether you need to measure only the interface or both the interface and the liquid level. If only the interface is to be measured, the same instruments that can be used for measuring the liquid level can be employed; magnetostrictive level gauges, electric float level gauges, guided wave radars, capacitive sensors, and so on are all suitable. If both the interface and the liquid level need to be measured, KTEK’s magnetostrictive and guided wave radar solutions can be used. 2. How to select a level measuring instrument for media that tend to form foam? It depends on the properties of the medium; if the dielectric constant of the medium is greater than 1.3, guided-wave radar can be used for measurement. If the medium foam is not severe, contains few impurities, and is free of crystallization or viscosity, magnetostriction can be considered.

This post was last edited by Wenxin Jiayuan on 2009-10-15 at 10:28. I encountered a problem regarding the measurement of the liquid levels of water and yellow phosphorus in a project, and I am here to seek advice. Conditions: 1. A yellow phosphorus tank, with phosphorus at the bottom and water on top; this setup is used to seal and isolate yellow phosphorus from air, while also allowing it to be heated. 2. The required water level must not be lower than 500 mm; if it drops below 500 mm, an alarm should be triggered and the pump should start to add water. The pump should stop when the water level exceeds 800 mm. 3. The level of yellow phosphorus liquid also needs to be measured. Requirements: 1. Since yellow phosphorus is usually in a solid state, when it is needed, hot water is added to turn it into a liquid state, after which it can be pumped out for use. 2. Due to the requirements of Party A, it is preferable that the measurement method be as economical as possible. Based on the above conditions and requirements, what measurement method should be used to complete this task? I hope experts can offer some guidance. If there are any instruments that can fulfill such functions, I would appreciate it if you could recommend them; model numbers would be ideal. Thank you!