Asymetrically cutting valve seats

The invention provides a cutting valve comprising a valve block, a gate, which is slidably within a cavity in the valve block from an open position to a closing and cutting position, an upper seat arranged in an upper part of the valve between the valve block and the gate, and a lower seat arranged in a lower part of the valve between the valve block and the gate, The valve further comprises an upper resilient member arranged between the upper seat and a lower resilient member arranged between the valve block and the lower seat. The cutting valve being distinctive in that the combination of height of upper seat, and lower seat, resilient member and any spacers on the lower side of the gate is selected so that an allowed travelling distance for the upper seat towards the valve block and an allowed travelling distance for the lower seat towards the valve block, are substantially equal. 本发明提供了种切割阀，其包括阀块；闸门，该闸门在阀块的腔体内从开启位置到关闭和切割位置是可滑动的；上部阀座，其在阀的上部部分中设置在阀块和闸门之间；和下部阀座，其在阀的下部部分中设置在阀块和闸门之间。阀还包括上部弹性构件，其设置在上部阀座和下部弹性构件之