the present invention is an apparatus with flexible membrane for oil storage and transportation , comprising of outer wall , installation opening , blocking cover , oil inlet , oil outlet and breathing orifice . the membrane is arranged in outer wall and fixed in the installation opening or the fixing part of outer wall . the rest of membrane is separated from outer wall . valve and quick coupling are arranged in both oil inlet and oil outlet . the chamber made of membrane stores the oil in a sealed condition to let the breathing take place outside the membrane so as to prevent direct breathing of oil with air , reduce breathing loss , protect the environment , minimize oxidation of oil , prevent water from entering oil and improve the quality of oil . also , it prevents oil vapor from mixing with air to improve the safety of storage and transportation as well as reduce the risk of fire and explosion . the flexible structure of the membrane facilitates the resistance to impact and other outer forces . according to the type of materials to be stored , different membranes can be chosen to store and transport liquid chemicals under low and ordinary pressure . this way of storage and transportation not only is environmental - friendly , safe and energy - saving , but also eliminates most of current oil vapor pollution .