Abstract: It is inevitable for the tight closure of a ball valve to be disturbed by its ball's wedging action, and its ball seat is an upset impulse amplifier with an inherent disturbance resistance index or a sealing maintaining factor m. The ball valve seat designed with equilateral triangle section methods of the invention can positively ensure itself a resistance to ball-wedged disturbance from eccentric drive to make a ball valve realize its tight closure by the floated pressure of balls or seats onto each other and ensure that the ultimate rotational resistance to the ball only relates to the ultimate pressure from/on one seat.

Abstract: A stem shoulder seal with double rings is composed of a sealing ring, a clamping ring and a spherical or conical stem shoulder, and the sealing ring is of a self-energized seal designed to its ultimate allowable strength and automatically free of any load beyond its ultimate strength. An assembly of independent dual stem seals, consisting of a stem shoulder seal with double rings, a stem cylinder seal with triangular sections and an isolating mating, can ensure that a stem has three seals which get well seated automatically at the same time to bear an identical ultimate medium pressure independently or without any mutual interference in service when assembled to the extent that the stem operating torque is just definitely increased, thereby ensuring that a stem sealing has a triple safety.

Abstract: A stem shoulder seal with double rings is composed of a sealing ring, a clamping ring and a spherical or conical stem shoulder, and the sealing ring is of a self-energized seal designed to its ultimate allowable strength and automatically free of any load beyond its ultimate strength. An assembly of independent dual stem seals, consisting of a stem shoulder seal with double rings, a stem cylinder seal with triangular sections and an isolating mating, can ensure that a stem has three seals which get well seated automatically at the same time to bear an identical ultimate medium pressure independently or without any mutual interference in service when assembled to the extent that the stem operating torque is just definitely increased, thereby ensuring that a stem sealing has a triple safety.

Abstract: It is inevitable for the tight closure of a ball valve to be disturbed by its ball's wedging action, and its ball seat is an upset impulse amplifier with an inherent disturbance resistance index or a sealing maintaining factor m. The ball valve seat designed with equilateral triangle section methods of the invention can positively ensure itself a resistance to ball-wedged disturbance from eccentric drive to make a ball valve realize its tight closure by the floated pressure of balls or seats onto each other and ensure that the ultimate rotational resistance to the ball only relates to the ultimate pressure from/on one seat.