| 摘要 |
<p>Title: A Valve The present invention relates to valves and in particular to valves of the type in which an obturator regulates fluid flow through the valve. The valve comprises a housing having an open-ended portion of circular internal cross-section, an inlet port and an outlet port, the ports being interconnected by a flow space An obturator is located within the flow space and attached to a movable head such that fluid flow through the valve may be regulated by the obturator by movement of the head . The head (18) retains a seal which bears upon the inner surface of the portion of the housing so as to resist fluid flow past the head . Preferred features include the provision of biasing means which maintain the seal in a state of compression and a seal which has the form of a hollow open-ended cylinder in which the hollow is frusto conical in shape. A bellows connecting the head to the housing and/or a seal provided on the head (18) and bearing against an external cover are especially beneficial since these provide secondary seals against leakage from the flow space . Numerous other advantageous features are disclosed and these include the provision of a leak detector , a readily dismantable valve and a specialised form of obturator , The valve has a wide range of applications and also presents special advantages for certain applications.</p> |
