| 摘要 |
<p>A valve, including a valve body, a stem, a backseat and packing means for providing a seal between the stem and the valve body, a rotational interlock between the backseat and the valve body, means on the stem engageable with the backseat for use in rotating the backseat and disengaging the backseat from the valve body, thereby permitting withdrawal and removal of the backseat from the valve body and avoiding the necessity of first removing the packing means from the valve body so as to provide access for removal of the backseat, characterized in that the stem has a single spline thereon comprising the means on the stem engageable with the backseat for use in rotating the backseat, the spline being so arranged relative to the backseat that it remains in operative engagement therewith when the stem is moved from a first position fully closing the valve to a second position fully opening the valve.</p> |
