| 摘要 |
<p>A choke includes a body (12) with an internal valve chamber (18), an inlet (14) and an outlet (16) communicating through the body into the valve chamber. A valve seat (20) surrounds the opening of the outlet into the valve chamber, and a valve member (30) is mounted within said body to move toward and away from said valve seat to control flow therethrough. Means are provided for moving the valve member in the body. The valve member (30) has a stem (32) and a replaceable, wear-resistant tip (42) which is provided with a sleeve insert (48) secured within the stem opening and has internal threads which mate with external threads on the end of the stem. The tip recess includes a groove (62) into which a portion of the sleeve insert is swaged to secure it tightly into the tip.</p> |
