| 摘要 |
<p>The invention relates to a method for loading and discharging tankers (1) for transporting oil, a method for transporting oil in tankers (1) and a pipe and valve system (6, 7, 8) in a tanker (1) for performing the method. According to the invention, gassing of hydrocarbon containing gas during loading and unloading is reduced by loading or unloading the cargo tanks (2) while the oil is maintained in contact with a generally saturated HC gas. This is done by saving the HC gas which is developed during loading or unloading, this gas later being used in further loading or unloading. This is made possible by means of a pipe and valve system (6, 7, 8) according to the invention. In accordance with one embodiment of the invention, the tanks are filled completely so that the oil is present in tank hatches (10) and risers (11) located at the top of the tanks (2). This results in that the gas volume above the cargo before a possible grounding is approximately equal to zero and, consequently, the necessary underpressure is obtained above the cargo for establishing a hydrostatic balance at the bottom of the tanker (1) with a minimum spill of cargo.</p> |
