Issues related to the measuring pipe of floating roof oil tanks
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Our company has recently installed internal floating roofs on the light oil storage tanks. There are three wave guide tubes inside the tanks: two are used for radar-level measurement, and one is used for manual level checking and sampling. To reduce oil and gas leaks, and to ensure that the air pressure inside the guide tube is the same as that above the floating disk, 4 Φ20 small holes were drilled at the top of each tube on the inner wall of the tank. The problem that arises now is that when no manual measurement is taken, the values displayed by both radar level gauges are identical. However, when a manual measurement is conducted, the resulting value differs from the radar-level data. Since we are dealing with storage tanks with capacities of 5,000 cubic meters and 10,000 cubic meters, even a difference of a few centimeters can lead to significant errors in the quality of the oil. I earnestly ask experts to advise on how to solve this problem. Additionally, how can liquid level measurement in internal floating roof tanks be carried out in such a way as to prevent oil and gas leaks (too many openings on the guided wave tube can cause oil and gas to leak above the floating disk), while still enabling accurate measurement of the liquid level?
This issue may be caused by the operations performed during manual measurement affecting the pressure balance inside the guided wave tube, thereby impacting the measurement data of the radar level gauge. When a manual gauging tube is opened for gauging or sampling, it may change the pressure or oil and gas composition inside the tube, thereby affecting the propagation and reflection of radar waves. Solutions to this problem may include: 1. **Optimizing the design and layout of the holes**: Adjusting the number or position of the Φ20 holes to ensure that air pressure remains balanced inside the waveguide and above the floating disk, even during manual measurements. The optimal pore size and layout may need to be determined through experiments. 2. **Use contactless level measurement techniques**: Consider employing more advanced contactless level measurement techniques, such as laser level gauges or radar level gauges with higher precision, as these techniques may not be affected by changes in air pressure. 3. **Regular calibration and maintenance**: Ensure that all level measurement devices are regularly calibrated and maintained to guarantee measurement accuracy. Especially after manual gauging, the radar level gauge should be checked and calibrated to ensure accurate readings. 4. **Increase monitoring points**: Add additional radar level gauges at various locations on the floating roof tank to verify the consistency of the data, and reduce errors and deviations through multiple data points. 5. **Improve operating procedures**: Improve the procedures for manual gauge measurement, such as opening the gauge tube slowly to minimize the impact on internal pressure. Ensure that pressure changes are minimized during operation in order to reduce the impact on the radar level gauge. Through the above measures, you can attempt to identify the root cause of the level differences, and reduce such differences through technical and operational optimizations, thereby improving measurement accuracy and minimizing oil and gas leaks. .
Thank you for the reply! My idea is that since manual gauging might result in uneven pressures in the three measuring tubes, leading to discrepancies in the liquid level, I thought of adding connection pipes to the top of the tank for these three tubes. In this way, when the manual gauging port is opened, the pressures inside all three measuring tubes would be in equilibrium with atmospheric pressure, thereby eliminating any pressure differences. This approach might help resolve the issue of inconsistent gauge readings. I haven’t implemented this solution yet; we’ll see how it works after trying it out in the future.
Your idea is quite creative; by adding connecting tubes, it is indeed possible to help balance the pressure within the three fluid measurement tubes, thereby reducing measurement errors caused by pressure differences. Before implementation, you can consider the following points: 1. **Pressure balance design**: Ensure that the design of the new connection pipes enables effective pressure balance, including the selection of pipe diameters, the layout of the piping, and the sealing at the connection points. 2. **Safety assessment**: Conduct a thorough safety assessment to ensure that the installation of the connection pipes does not affect the structural integrity of the tank, while also taking into account the risk of oil and gas leaks. 3. **Simulation testing**: Before the official installation, simulation tests or small-scale trials can be conducted to evaluate the effect of pressure balance and its impact on the accuracy of level measurement. 4. **Monitoring and Adjustment**: After implementation, it is necessary to continuously monitor the operating status of the system, especially the accuracy of liquid level measurement and any oil or gas leaks. Adjust the operating parameters or further optimize the design based on the actual operation results. I hope these considerations will help you feel more confident when implementing the new plan, ensuring that the desired results are achieved. After the trial, don’t forget to analyze the data to see how it performed, so as to make further adjustments and improvements. .
Okay, thank you. We will take your suggestions into account to adjust the relevant plans.