Liquid gasification filling system consists of liquid storage tank, liquid pump and air purifier. In order to ensure the normal operation of the liquid pump, besides the reliability of the structure of the pump itself, the piping technology is also very critical. Improper piping, if it is light, it will cause "cavitation phenomenon" of the liquid pump, and the decrease of flow rate will lead to large mechanical loss of the pump; if it is serious, the filling pressure cannot be improved due to the serious gasification of the liquid in the pipe, the pump cannot work normally. Therefore, the following problems should be paid attention to when managing:
1) the base of the storage tank should be more than 1 m higher than the center of the liquid oxygen pump to ensure that the inlet of the pump has a higher static pressure (higher than the saturation pressure corresponding to the temperature );
2) shorten the length of the pipeline from the storage tank to the pump inlet as much as possible to reduce the pressure drop caused by the flow resistance. A section of bellows and filters are installed at the entrance of the pump;
3) strengthen the heat preservation of the inlet pipeline to reduce the temperature rise caused by the introduction of external heat;
4) An Air return pipeline should be configured in the suction cavity of the pump, and a blow-off valve should be installed. Once cavitation occurs, open the blow-off valve to exhaust. Connect the return pipe to the gas phase space on the top of the storage tank, there should be no lower bending section, and the insulation layer should be wrapped;
5) the discharge pipe of the pump should be considered to compensate the temperature stress. The pipe is equipped with check valve, stop valve, safety valve and pressure gauge with alarm automatic control device.
