The LNG storage tank has no pressure – what to do if it’s empty? . .

It is necessary; otherwise, the high temperature inside will cause rapid vaporization when liquid is released. It is best to use liquid nitrogen to gradually cool down the storage tank

Pre-cooling is required; otherwise, a large amount of BOG will be generated. Under normal circumstances, after the contents inside the tank are used up, it should be sealed with nitrogen for safety reasons.

Generally, the use of light is not allowed; when the pressure drops to a certain level, it can no longer be used

After use, it is best to maintain pressure with nitrogen, and pre-cool it with liquid nitrogen before use; otherwise, LNG will have to be used for pre-cooling, which results in excessive losses

Fill it with nitrogen; pre-cool it before using it next time, and that’s it.

It’s run out? It should be considered an accident that requires investigation. 1 If there is still some residual pressure after it’s used up, it’s a near-miss accident; normal use can continue, and the responsible party can be fined. 2 If negative pressure occurs after it’s used up, then it needs to be replaced, and in that case it becomes a full-blown accident

If a low-temperature submersible pump is used for LNG storage tanks, there is a minimum liquid level limit, and no re-precooling is required for short periods of use in vehicles.

I’m not sure whether your LNG storage tank is a standard 60-cubic-meter tank used in gas stations, or a large LNG storage tank with a capacity of several thousand to tens of thousands of cubic meters used in LNG plants. During normal operation, in gas station storage tanks, when the liquid level reaches several hundred units, it becomes impossible to pump out the liquid inside the tank; however, BOG flash vapor is generated due to prolonged idling, and this vapor is then vented. The large LNG storage tanks at the liquid plant are equipped with low liquid level interlock protection; when the liquid level drops below 10%, the discharge valves of the tanks close automatically, and the cryopumps also stop operating. When an LNG storage tank at a gas station is put back into use after being left unused for an extended period without pressure, it needs to be pre-cooled using liquid nitrogen. This situation generally does not occur in LNG storage tanks at liquid gas plants

LNG storage tanks are not pressure-free; they are tanks at atmospheric pressure. It’s impossible to use up all the LNG – at least a minimum liquid level must be maintained. If the tank has to be pre-cooled every time or if it needs to be refilled repeatedly, the facility is essentially on the verge of closing down