| 摘要 |
<p>This invention relates to a pneumatic actuator for valves, comprising an actuator body (10) and two pistons (14, 15) housed in said body and moving in parallel in opposite directions, to move away and to move towards each other. At least one piston (14) has an adjustment screw (19) screwed into it with a head (19') in a position to intercept and stop the other piston (15) when the two pistons move towards each other, and an end (19'') facing towards a respective end flange (11) of the actuator body and accessible for adjustment of the screw through a hole (20) in said flange and sealed by a cap with a seal (21).</p> |
