How long will the refueling station refuel?

Under normal circumstances, Sinopec multi product dispenser unloading, the need for oil for 15 minutes before they can refuel it! Because the unloading process of the momentum, making the original deposition in the bottom of the debris particles suspended in the oil, if unloading oil immediately after the oil, the particles may be followed by the tank gauging equipment, affecting the quality of oil it! So pro, or to remember and so on Oh, unloading oil, do not rush to refuel!