| 摘要 |
<p>A spindle (8) comprises a through throttle (9) for providing a connection from the inlet (6) via said throttle and an actuator unit (2), sensitive to a liquid flow, to the outlet, in the first position of the spindle. The spindle is forced by a spring into the first position, when the pressure is equal on both sides of the throttle of the spindle. The throttle of the spindle is dimensioned in such a manner that the pressure fall over the throttle, at least by a liquid flow through at the operating pressure of the fire fighting installation, is sufficiently great to set the spindle in motion from the first position towards said second position. The spindle comprises a shoulder face (12) upon which the liquid pressure of the inlet (6) acts after the spindle (8) has moved off its first position, in order to boost the spindle towards its second position.</p> |
