| 摘要 |
<p>PCT No. PCT/NO92/00007 Sec. 371 Date Nov. 3, 1993 Sec. 102(e) Date Nov. 3, 1993 PCT Filed Jan. 17, 1992 PCT Pub. No. WO92/12893 PCT Pub. Date Aug. 6, 1992.The invention relates to a method for loading and discharging tanks (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 and unloading. This is made possible by 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 a cargo.</p> |
