Long Throttling Lip on the disc retards flow when seating position is approached. Disc chattering is prevented, and wiredrawing of seating surfaces is reduced.

• 长节流唇位于阀瓣上，当流体接近阀座密封位置时可以阻止减速流体，从而防止阀瓣颤动，减轻阀座密封面的拉丝现象。