| 摘要 |
PURPOSE:To facilitate a rotating action of a valve by providing a cavity between the upper face of a plug and a plug suppressor of a plug vlve suitable in use for a high pressure pipe and introducing into this cavity a fluid with a pressure corresponding to the pressure of the fluid in the pipe. CONSTITUTION:Packing seats 3, 4 are providd in contact with the upper and lower sections of a plug 2, and packings 5, 6 are sealed. An upper and a lower covers 7, 8 of the plug 2 are provided, and a worm wheel 14 is fixed to a plug shaft extending through the upper cover 7 and is rotated by a rotating worm 15. A cavity 16 surrounding the plug is formed between the upper cover 7 and the packing 5, and a fluid with a pressure corresponding to the pressure of the fluid in the pipe is inroduced into the cavity 16 through a passage 17. According to this constitution, the plug push-up pressure of the fluid in the pipe and the plug push-down pressure of the introduced fluid are balanced against each other, resulting in a smooth rotating action of the plug. |
