| 摘要 |
<p>A ball valve, for use in catalytic fluid cracking plant in oil refineries or in piping to transfer dust-laden fuel gases from blast furnaces to boilers, consists of two cock plates which form the two halves of the ball. Each has its own drive so that they can be turned in synchronism. The valve surfaces which are exposed to the fluid are thus not in sliding contact with the valve housing and can be hard faced (stellited).</p> |
