Experiment and Analysis of LNG Storage Tank Airtightness

With the development of my country’s LNG industry, the use of LNG has become more and more extensive, and the number and volume of cryogenic storage tanks in the receiving station have become larger and larger, which also increases the potential danger to a certain extent. Therefore, we need to conduct regular inspections on storage tanks to ensure their safety. Especially for its air tightness, it is also of special concern to everyone. Next, I will tell you about the air tightness experimental testing of lng storage tanks.

Air tightness test of LNG Storage Tank

For the low temperature insulated pressure vessel, whether it is the outer interlayer or the inner cylinder, if there is a small leak, the vacuum degree of the interlayer cannot be maintained. We can judge the fineness of the low temperature insulated pressure vessel through the vacuum degree test. However, from the perspective of the safety of the pressure device, it is also necessary to conduct experiments to check whether the various connecting pipes, valves and their connecting parts of the storage tank are fine. Before the air tightness test, it is necessary to check whether the valve is suitable for the medium contained, whether the function meets the requirements; whether the layout of the pipeline is reasonable, and whether the pipeline is damaged or bent during use. Then, according to the requirements of document 2, the air tightness test was carried out. After the air tightness test, no abnormal noise and no visible deformation were found, and there was no air leakage after checking the soap solution. The tightness of the tank and each pipeline was good.
Infrared imaging is currently the only diagnostic technology that can instantly visualize and verify thermal information. As a new type of non-destructive testing and evaluation method, infrared thermal imaging technology has the characteristics of intuitive, rapid and non-contact temperature measurement. Because almost all devices generate heat before they fail. Infrared imaging technology can quickly and safely find faults in equipment before they occur.
An infrared thermal imager is a detection device that detects infrared energy (heat) non-contact and converts it into an electrical signal, and then generates a thermal image and a temperature value on the display, and can calculate the temperature value. Infrared thermal imaging cameras can accurately quantify and measure the detected heat, not only can investigate thermal images, but also identify and strictly analyze the faulty areas of heating.
The inspection was quantified by non-contact temperature measurement using a FLIR thermal imaging camera. After testing, no significant temperature change was found in the tank shell and the connecting pipeline, and the external tank has good integrity and no leakage occurs.
The above is the relevant analysis of the air tightness test of the lng storage tank. In this, the infrared imaging detection technology is also mentioned, which is also a new type of non-destructive testing evaluation method.