After a LNG tanker arrives at the station, guide and supervise it to stop at the designated unloading position, connect the grounding wire and pad the anti sliding wood block.
Second, check the liquid temperature of the tank car and the liquid temperature of the storage tank to determine the unloading scheme. When the liquid temperature of the storage tank is higher than that of the tank car, the liquid inlet at the top should be adopted; otherwise, the liquid inlet at the bottom should be adopted.
(III) the gas-liquid phase and gas-phase unloading hoses of LNG are in good condition.
IV. check the pressure and liquid level in the storage tank in the storage tank area.
(V) check whether all valves from the unloading platform to the storage tank are in normal position according to the LNG filling process
6. After the above points are correct? The operator in the station shall check and record the pressure, temperature and liquid level of the tanker.
VII. The operation from the unloading area to the tank farm shall be carried out by the operators in the station, and the operation from the tank car to the unloading platform shall be carried out by the tank car escort. During filling, patrol check the working conditions of all process valves, pipelines and instruments, make records and pay attention to avoiding risks.
VIII. Specific unloading operation.
1 pressurize the tank car and increase the tank car pressure to the tank pressure plus 0.2MPa. The maximum tank car pressure shall not exceed 0.66mpa.
2. Correctly open the liquid inlet valve after confirming that the tank car pressure reaches the specified value.
3. Observe the liquid inlet pipe. If there is frost and liquid flow sound, it indicates that the unloading is normal. If the joint leaks, stop the unloading operation immediately to eliminate the danger.
4. Observe the pressure and liquid level changes of the tank car and the storage tank. Keep the pressure difference at about 0.2MPa through the decompression of the storage tank and the pressurization of the tank car. The maximum pressure of the tank car shall not exceed 0.66mpa.
5 close the inlet valve of the liquid phase pipe and the cut-off valve of the storage tank after the LNG is discharged.
