Abstract: A valve includes a ball coupled to a stem which is turnable by an operator element. The ball is formed with a flow passage and the ball is sealed in a valve seat by means of seals. The stem includes bypass structure, which upon rotation of the stem, is alignable with an upstream diverging tube and with a downstream diverging tube to allow bypass fluid flow from the upstream diverging tube to the downstream diverging tube for balancing a difference in pressure between upstream and downstream portions of the valve.

Abstract: A valve includes a ball coupled to a stem which is turnable by an operator element. The ball is formed with a flow passage and the ball is sealed in a valve seat by means of seals. The stem includes bypass structure, which upon rotation of the stem, is alignable with an upstream diverging tube and with a downstream diverging tube to allow bypass fluid flow from the upstream diverging tube to the downstream diverging tube for balancing a difference in pressure between upstream and downstream portions of the valve.

Abstract: Aspects of embodiments of the invention relate to a spring-return actuator comprising a first piston movable between a first and a second position by pressurized fluid to move a load; a safety system comprising a second piston movable by the pressurized fluid to arm the safety system and which returns the first piston from the second position to the first position when de-energizing the 3/2 pilot valve or when the pressure of the pressurized fluid drops below a safety pressure threshold; and a differential fluid channel for providing the pressurized fluid and configured so that the first piston while working to move the load remains substantially disengaged from the safety system being armed.

Abstract: Aspects of embodiments of the invention relate to a spring-return actuator comprising a first piston movable between a first and a second position by pressurized fluid to move a load; a safety system comprising a second piston movable by the pressurized fluid to arm the safety system and which returns the first piston from the second position to the first position when de-energizing the 3/2 pilot valve or when the pressure of the pressurized fluid drops below a safety pressure threshold; and a differential fluid channel for providing the pressurized fluid and configured so that the first piston while working to move the load remains substantially disengaged from the safety system being armed.