| 摘要 |
<p>The valve (10) comprises a housing (12) having an open-ended portion (14) of circular internal cross-section, an inlet port and an outlet port, the ports being interconnected by a flow space (16). An obturator (20) is located within the flow space (16) and attached to a movable head (18) such that fluid flow through the valve (10) may be regulated by the obturator (20) by movement of the head (18). The head (18) retains a seal (30) which bears upon the inner surface of the portion (14) of the housing (12) so as to resist fluid flow past the head (18). …<??>Preferred features include the provision of biasing means which maintain the seal (30) in a state of compression and a seal (30) which has the form of a hollow open-ended cylinder in which the hollow is frusto conical in shape. A bellows (24) connecting the head (18) to the housing (12) and/or a seal (28) provided on the head (18) and bearing against an external cover (26) to provide secondary seals against leakage from the flow space (16). …<??>Included is the provision of a leak detector (64), a readily dismantable valve and a specialised form of obturator (20).</p> |
