Cryogenic storage Dewar, the self-pressurizing cryogenic container, hence the name “self-pressurizing liquid nitrogen tank”!
Self-pressurization is both its selling point and the core of its work, an ability that allows it to easily output liquid nitrogen to supplement other cryogenic vessels.
But what should I do if the cryogenic storage dewar fails and does not pressurize anymore?
A: First analyze the problem, find the cause, and then deal with it!
There are generally three reasons why cryogenic storage dewars are not pressurized: the venting valve is open, the pressurization valve is not open, and there are leaks in the container.
Cause 1: Opened the venting valve
Analysis: Venting valve to do pressure relief, discharge residual liquid use, cryogenic storage Dewar static has been open, do not exclude because of careless forget to close the venting valve, go to open the booster valve, the booster is not as fast as the pressure relief, resulting in the pressure does not go up.
Treatment: Check yourself, if open directly off, and then open the booster valve can be.
Cause two: not open the booster valve
Analysis: booster valve booster with, do not open the natural grant can not pressure.
Treatment: Check by unscrewing yourself to see if the booster valve is open, not open directly to open, and vice versa is the third reason.
Reason 3: There is a leak in the container
Analysis: If there is a leak in the cryogenic vessel and the vacuum is broken, it is impossible to pressurize.
Treatment: Check the appearance, where there is frost where is the cryogenic storage Dewar leakage, you can contact the manufacturer to deal with.