| 摘要 |
<p>The present invention relates to an arrangement in a valve actuator (101) operating on a valve stem (113) provided with a piston (114) so as to close or open the valve (111), and in order to arrive at a variable area type hydraulic piston/cylinder, it is according to the present invention suggested that in addition to the valve stem piston (114) there could be provided one or more supplemental pistons (124).</p> |
