The safety of Dewar flasks

Before leaving the factory, LNG Dewar must undergo special inspection. After the dewar is routinely inspected, it needs to be inflated for fire, explosion, falling, gunshot and other tests. The gas cylinder can be used only after passing the test.
 
The LNG vehicle-mounted gas cylinder is a low-temperature insulation pressure vessel designed with a double-layer (vacuum) structure. The inner tank is used to store low-temperature liquid liquefied natural gas, and its outer wall is wrapped with multiple layers of thermal insulation materials, which has super thermal insulation performance.
 
At the same time, the jacket (the space between the two layers of containers) is pumped into a high vacuum, forming a good insulation system together. The design of the Dewar shell and the support system can withstand the relevant external forces generated by the vehicle during driving. The cylinder liner is designed with a two-stage safety valve to protect it from overpressure. The first opening of the pressure vessel in the case of overpressure is the main safety valve, which acts to dissipate the pressure caused by the pressure rise due to the normal heat leakage loss of the insulating layer and the support, or the pressure caused by the accelerated heat leakage after the vacuum is broken and under fire conditions. rise. The pressure setting point of the auxiliary safety valve is higher than that of the main safety valve. When the main safety valve fails or is blocked, the auxiliary safety valve is activated.