Application of helium mass spectrometer leak detector for low-temperature storage tanks

At present, the application scope of cryogenic insulated pressure vessels is expanding and developing faster and faster. The regular inspection of cryogenic insulated pressure vessels is mainly reflected in the invisibility of the inner container and the special requirements for the thermal insulation performance of the vacuum jacket, and there are certain risks during operation.

Therefore, the leak detection of cryogenic pressure vessels is particularly important. Generally speaking, the measurement of the leak rate of cryogenic pressure vessels usually consists of a helium mass spectrometer leak detector, a vacuum system, a standard leak hole, a tracer gas source (helium), etc.

Now, let's take a look at the relevant descriptions of the helium leak detection of cryogenic containers for your reference.

I. Reasons for Leak Detection of Cryogenic Containers

Cryogenic containers mainly store liquid gases. Considering safety and cost, there are high requirements for the leak rate of cryogenic containers. Therefore, leak detection of cryogenic containers is particularly necessary. For example, Dewar flasks, LNG storage tanks, and cold tank containers all need to be detected by a helium mass spectrometer leak detector. The leak rate index is one of the main technical indicators for evaluating the product quality of large cryogenic containers. Accurately quantifying the leak rate value is an important guarantee for the thermal insulation, reliability, and safety of the product.

II. Leak Detection Methods for Cryogenic Containers

The helium mass spectrometer leak detector of Nuoyi Technology provides two leak detection modes, the positive pressure mode and the negative pressure mode. The negative pressure mode (vacuum mode) is mostly used for the leak detection of cryogenic containers. Connect the helium mass spectrometer leak detector to the vacuum system, preferably near the exhaust port. The vacuum system will have a pump unit for evacuating, so connecting the helium mass spectrometer leak detector at the inlet of the pump is in the direction of the gas flow. It is easy for a part of the partial pressure to be distributed to the helium mass spectrometer leak detector, thus achieving the effect of leak detection.

III. Instructions on the Leak Detection Form of Cryogenic Containers

Using the vacuum mode of the helium mass spectrometer leak detector to detect cryogenic containers is the most widely used detection method in the industry. The cryogenic container is evacuated using a vacuum system, and the helium mass spectrometer leak detector is connected to the exhaust end of the vacuum furnace. Since the gas flow will all go towards the vacuum system, if there is a leak when spraying helium gas, it will all pass through the suction port of the leak detector. After the helium mass spectrometer leak detector detects the helium gas, there will be a change in the leak rate, thus achieving the measurement effect.

Reference Precautions:

The measuring pipeline should be equipped with a vacuum gauge tube joint that meets the requirements of JB/T8105.1 or JB/T8105.2. In addition, a joint that can connect the standard leak hole should also be set up.

Preheating and evacuating the inner container

In order to ensure that the inner container can be smoothly and quickly evacuated to the predetermined vacuum degree required for leak detection, and at the same time, the water vapor on the surface of the inner container and in the cracks between it and the components can be completely evaporated, the inner container should be sent to the heating room for 6 to 8 hours of heating treatment in advance, and then connected to the vacuum unit for evacuation (which takes about 18 to 24 hours). When the vacuum degree reaches 10Pa, the inner container can be removed from the heating room.

Anhui Nuoyi Technology provides a complete product line of helium mass spectrometer leak detectors, from portable helium mass spectrometer leak detectors to leak detection modules, providing negative pressure leak detection (vacuum method) and positive pressure leak detection (sniffer probe method) to meet various applications.

In view of the confidentiality of customer information, if you need to learn more about the helium mass spectrometer leak detector for cryogenic storage tanks, you can contact us:

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