| 摘要 |
<p>PURPOSE:To restrain water hammer pressure even though the closing speed of a valve is high, by once stopping the operation of the valve element in the vicinity of a full close position, and by holding this condition for a predetermined time. CONSTITUTION:In a valve manipulating operation in which after the valve element is moved in a closing direction at a rapid closing speed from the initial opening degree to the full close position, the valve element is held at set opening degree for a set holding time, and thereafter, the valve element is moved to the full close position, the above-mentioned set opening degree is set to 10 to 20% of the valve stroke from the initial opening degree to the full close position, and the holding time is set to about 20% of the time required for moving the valve element from the initial opening degree to the full close position at the above-mentioned valve closing speed with no stop.</p> |
