摘要 |
<p>A shut-off device of the double block-and-bleed type comprising a flow passageway accommodating two shut-off members provided with through-going cavities, and a drain means. The flow passageway is provided with an inlet and an outlet. Each of the shut-off members may be moved between a position in which the flow passageway is open and a position in which the flow passageway is closed. In association with the shut-off members two auxiliary chambers are communicating with cavities of the shut-off members. The shut-off device is formed of a single undivided casing. The shut-off members are truncated cone-shaped and mounted in matching truncated cone-shaped recesses in the common casing. As a result, the overall length of the shut-off device may be reduced compared to prior art. Moreover, the tightness at high pressure, e.g. above 100 ato. is enhanced.</p> |