As an important part of laboratory liquid nitrogen replenishment – ln2 supply tank, liquid replenishment needs to be pressurized, and the pressurization valve must be opened to pressurize!
In its structural design, the valve plays a general control role and replaces the open mouth of the ordinary liquid nitrogen tank; the vacuum and insulation materials of the double tank body are only used for heat preservation and liquid nitrogen storage, and are not used as a sample refrigeration room. The entire container is nearly sealed, with only a few valves connected to the outside. When there is a “task” of liquid nitrogen output, the booster valve must be opened!
So can it stay on? After all, the ln2 supply tank is a liquid nitrogen supply container, and its purpose is to replenish liquid. Since liquid replenishment requires opening the booster valve, why not keep the booster valve open all the time? Save worry and effort!
Of course not!
Answer: If the set pressure value of the container is exceeded, the double safety valve protection is triggered, which has potentially dangerous consequences!
The ln2 supply tank is a low-pressure liquid nitrogen tank. Its factory pressure does not exceed 0.1MPa. The standard working pressure is in the range of 0.05MPa-0.09MPa, which can be ≥0.05MPa, but cannot be equal to 0.09MPa.
Moreover, in the non-working state, the ln2 supply tank is actually a pressureless container, and the pressure gauge value displays 0. Only when rehydration is needed, close the vent valve, open the booster valve, and put external hot air into the booster pipe. Add a small amount of liquid nitrogen to pressurize.
So, you know, if the boost valve is kept open, hot air will continuously enter the boost coil between the inside and outside of the tank, continue to vaporize and pressurize, and then pressurize again. When the pressure exceeds the container standard, the safety valve will The pressure relief protection is automatically turned on and a hissing deflation sound is made. If this happens many times, the safety valve may be damaged if it bears too much pressure. If the pressure cannot be released in time, the tank may explode. This is a potential danger!
Therefore, it is recommended to use the manufacturer’s recommended pressure when using the ln2 supply tank to pressurize and replenish fluids. After reaching the pressure, stop pressurization and start infusion, and turn off pressurization after completion. When replenishing water without pressurization, close the pressurization valve of the liquid nitrogen supply tank to ensure your own safety!