It is possible to assist the disc to close rapidly where quick action is necessary to avoid a sudden reversal of flow or set the lever and weight at any position to get desired operating performance.

• 有些地方,例如要求阀瓣能够迅速关闭,或者为了获得某种理想的操作性能而需要设置操纵杆和压铁的地方,都要求关闭操作必须迅速有效,以避免突然的回流。