| 摘要 |
<p>A control valve comprises a body having a fluid inlet and a fluid outlet and a rotary member provided with two separate internal passages, each capable of connecting the fluid inlet to the fluid outlet, according to the angular position of the rotary member in the said body. A control system is arranged in one of the passages for controlling fluid along the passage independent of the angular position of the rotary member, while the control of flow of fluid in the other passage is effected by adjustment of the angular position of the rotary member. The one passage is the main passage for normal use and the other passage is a secondary or by-pass passage for use when work is required to be done on the control system in the one passage. The control system in the one passage comprises valve members operated by a rod for closing seats in the passage.</p> |
