| 摘要 |
<p>Fluid valves having an integral safety shut-off are described. An example control valve having opposing seating surfaces includes a first bonnet removably coupled to the control valve. The first bonnet has a first bore receiving a portion of a first valve trim. The first valve trim comprises a first valve stem operatively coupled to a first valve plug or closure member to engage one of the seating surfaces to provide a fluid seal between the first bore and the portion of the first valve trim. Additionally, the control valve includes a second bonnet removably coupled to the control valve. The second bonnet has a second bore receiving a portion of a second valve trim. The second valve trim comprises a second valve stem operatively coupled to a second valve plug or closure member to engage the other one of the seating surfaces to provide a fluid seal between the second bore and the portion of the second valve trim. A surface of the second valve plug or closure member is to be substantially flush with an inner surface of the control valve when the second valve plug or closure member is not in use to enable fluid flow through the control valve to be substantially unaffected by the second valve plug or closure member.</p> |
