What are the specific process flow of double-layer oil tank refueling

The double-layer oil tank refueling process is divided into two types: submersible pump and self-priming. When the pressure vessel is equipped with a vapor recovery system, the vapor recovery process should be added to the two basic processes

1.Submersible pump refueling process
1.1 When one kind of oil is supplied to multiple tankers (guns) at the same time, the submersible pump type refueling process should be adopted;
　　
1.2When the length of the oil outlet pipeline between the oil tank and the dispenser is greater than 50m, the submersible pump refueling process should be adopted.
　　
2.Self-priming refueling process
2.1When one type of oil is supplied with no more than four guns at the same time, the self-priming refueling process should be adopted;
　　
2.2 When the length of the oil outlet pipeline between the oil tank and the dispenser is not more than 50m, the self-priming refueling process should be adopted. 2.3 Each fuel dispenser of the pressure vessel should be provided with a separate fuel inlet pipe according to the fuel type.
　　
3. Process with oil and gas recovery system
Unloading oil and gas recovery process (1) When the double-layer oil tank adopts the unloading oil and gas recovery process, the airtightness of the system must be ensured. The gasoline unloading interface and the oil and gas recovery interface should be installed with DN100 valves. (2) Gasoline breather pipe mouth should Install a mechanical breathing valve. The working pressure of the mechanical breathing valve should be positive pressure 2000Pa ~ 3000Pa, negative pressure 200P (3) In order to prevent the occurrence of oil unloading in the closed system of double oil tanks, it can be connected in the unloading pipeline tank. Install the oil unloading anti-overflow valve.