I. Inspection of liquid nitrogen storage tank before use

　　When the liquid nitrogen tank is filled with liquid nitrogen, the first thing to do is to check whether the shell has any depression and whether the vacuum exhaust port is intact. If it is damaged, the vacuum will be reduced, and if it is serious, the air inlet can not be insulated, so that the upper part of the tank will be frosted, and the liquid nitrogen loss will be large, losing the value of continued use. Secondly, check the inside of the tank, if there is a foreign body, must be removed to prevent corrosion of the inner liner.
Second, the filling of liquid nitrogen

　　Be careful when filling liquid nitrogen. For new tanks or tanks in dry state, it must be filled slowly and pre-cooled to prevent the inner liner from being damaged when cooling down too quickly, which will reduce the service life. When filling with liquid nitrogen, do not pour liquid nitrogen over the vacuum exhaust port, as this may cause the vacuum level to drop. The cover plug is made of adiabatic material, which can prevent the evaporation of liquid nitrogen and also play the role of fixing the cylinder, so the switch should minimize the wear and tear to prolong the service life.

　　Third, the storage capacity of liquid nitrogen in liquid nitrogen tanks:

　　Liquid nitrogen tank storage of liquid media, please be sure to close the inlet / discharge valve and the pressure valve, you must open the venting valve.

　　Fourth, the liquid nitrogen tank in the transportation of liquid nitrogen:

　　When transporting liquid nitrogen medium in liquid nitrogen tank, please make sure that the switching status of each valve should be the same as that in storage, and please put the base of the packing box under the container seat circle, and use the rope to fix the liquid nitrogen tank container reliably on the car, so that the liquid nitrogen tank will not shake in the process of transportation.
V. Infusion of liquid nitrogen in liquid nitrogen tank:

　　If you want to output liquid nitrogen from the liquid nitrogen tank, please operate according to the following procedures:

　　Close the venting valve; open the pressurizing valve; observe the pressure gauge; when the pressure rises to 0.05MPa (0.5kg/cm2), open the drain valve, then you can infuse liquid continuously.

　　Sixth, the use of the process of checking

　　The use of the process should be frequently checked. You can observe with your eyes and touch the shell with your hands, if you find the appearance of hanging frost, you should stop using it; especially when the inner wall of the neck tube is attached with frost and ice, you should not use a knife to scrape, in order to prevent the inner wall of the neck tube from being damaged, resulting in poor vacuum, but you should take out the liquid nitrogen and let it melt naturally.