| 摘要 |
<p>The valve is provided at its stopper (3) with a pin (4) combined to a spindle (5) which are coaxial and prevented to move in this direction but capable of rotating freely one with respect to the other so that, by means of the spindle (5), the nut (6) and the corresponding motor (9), the longitudinal movement of the stopper (3) is obtained in the valve opening and closing operations whereas, by applying directly a rotary motion by means of a second motor (23) to the pin (4) which does not affect the spindle (5), the stopper (3) rotates on the valve seat (2), to the closing position, causing a friction and consequent closer self-cleaning action. <IMAGE></p> |
