Poppet valve actuator apparatus

摘要

A poppet valve actuating apparatus includes an actuator for driving a valve poppet closed with substantial but momentary force to effect tight valve shutoff. After driving the poppet closed with a momentarily-applied relatively high-value force, the actuator then automatically reduces the poppet seating or holding force for maintaining the value in the closed position by automatic release of an integral detent coupling that applies a lower-value auxiliary spring holding force after the poppet is seated. The reduced value holding force prevents cold flow of the poppet material during extended periods wherein the poppet is in a closed position.