Does the questioner want to ask about "the process steps of liquid nitrogen tank vacuuming and nitrogen replacement"?
1. Replace the storage tank. After the storage tank is replaced, a small amount of liquid nitrogen will be retained.
2. Replace other pipelines and storage tank booster carburetor and unloading carburetor.
3. Perform nitrogen replacement by heating and vaporizing liquid nitrogen, and arrange the replacement according to the process pipeline layout.