| 摘要 |
PURPOSE: To improve durability of a spare packing ring by providing the constitution that when an outermost packing ring fails, supply of a lubricator is shut off only for the front face of the spare packing ring adjacent to it, while the back side is maintained as it is (in low pressure). CONSTITUTION: A packing ring M3 is at a special position when not functioning as a spare packing ring, that is, in normal operation, but it functions as a packing ring, when a packing ring M4 fails. It does not function as a packing ring, when a lubricator with the same pressure acts on spaces K2 and K3. The lubricator is supplied or drained through pipes 6 and 7 shown by an arrow. When the packing ring M4 fails, its seal is lost, the lubricating oil moves from a lubricator chamber S, and this pressure acts on the spare packing ring M3. In such an operation state, the pipe 7 is closed, and drainage of the lubricating oil from the space K3 is prevented, while the pressure of the lubricating oil in the pipe 6 remains, that is, kept at a pressure lower than the pressure of sea water W. |
