| 摘要 |
A well-head (W) having a casing (C) through which a fluid flows. Apparatus (10) for controlling the flow of fluid has an output shaft (14) insertable into a sleeve (18), sleeve (18) being insertable into the casing at its fluid outlet end (E). The sleeve extends from a hub (12) which is placeable into the outlet end of the casing and extends down into the casing. The output/draw shaft (14) extends up through the sleeve, and has a draw nut (34) and a shut-off valve (16). The valve (16) allows fluid flow through the output/draw shaft during installation of the sleeve but shuts off flow thereafter. The sleeve has a circular wall (22), defining a longitudinal bore (24) having an inner diameter (D1) which gradually increases from the upper to the lower end of the sleeve. Circular wall (22) thus has a tapering thickness along the length of the sleeve. The output/draw shaft (14) is inserted up through the sleeve and has a tapered external diameter corresponding to the internal taper of the sleeve. The output/draw shaft is drawn upward inside the sleeve, by tightening the draw nut, thereby forcing the wall of the sleeve to expand outwardly and adhere to the inside of the casing.
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