Seat ring and wedge seating surfaces are set on a 5 degree angle from vertical to minimize sliding contact of the wedge and seat ring during opening and closing.

• 阀座环和楔形闸板阀座表面与垂直线成5度角，这样在开启和关闭过程中，楔形闸板与阀座环的滑动接触摩擦力降到最小。