What is this device?

This is a safety valve, used to control the pressure inside the liquid nitrogen tank and prevent safety accidents caused by excessive pressure. .

The response on the 4th floor was very professional. Split-type low-temperature three-way ball valve

This post was last edited by CHANGBAISHI on 2024-7-5 07:11. The correct orientation for the valve (switch valve) in the image should be in the middle position (perpendicular to the ground), providing double protection. When a rupture disc on one side breaks or a safety valve on one side needs to be inspected and replaced, the selection can be switched to disconnect that side, allowing the other side to continue in use for ease of maintenance. ****But still, the device’s user manual should be followed. This system comes with four types of insurance, for reference.

The low-temperature storage tanks are equipped with safety valves; below them are rupture disks. Some of these tanks do not have rupture disks and only have safety valves. As for whether it is one for use and one as a backup, this depends on the design documents; in most cases, it is not. The set pressure of a safety valve does not exceed the design pressure, while that of a rupture disc generally exceeds the design pressure. If you’re not sure, just follow the requirements of the design drawings. Of course, on the other hand, if you don’t even know the most basic safety valves and rupture disks, then you really aren’t suitable for working in this field – the responsibility is **great**. It is impossible to determine from the photos whether the safety attachments meet the requirements; on-site verification is necessary.

Okay! My reply was reviewed. Above is the safety valve and below is the burst disc; the burst disc has a nameplate, and in this case the information might be engraved on the holder. The setting pressure of the safety valve shall not exceed the design pressure of the tank, while the pressure of the rupture disc generally exceeds the design pressure; the specific requirements depend on the design documents. Installing two sets of safety accessories does not mean one is for backup use; in most cases, such low-temperature storage tanks do not have one unit as a backup, and it depends on the requirements specified in the design documents. Low-temperature storage tanks are primarily subject to vacuum level requirements; for specific details, refer to TSG21-2016. The requirements vary significantly depending on the type of low-temperature storage tank. I won’t go into more details for fear that the more you hear, the more timid you’ll become.

Low-temperature three-way ball valve, usually equipped with 2 safety valves, one in use and one as a backup