A spring-loaded ball valve includes a spring, a first pin, a second pin, and a handle. The spring is configured to apply pressure to the first pin and second pin when the ball valve is in both the fully open and fully closed positions. The spring applies maximum torque when the ball valve is in the fully open or fully closed position to ensure the valve remains in the fully open or fully closed position.

A spring-loaded ball valve includes a spring, a first pin, a second pin, and a handle. The spring is configured to apply pressure to the first pin and second pin when the ball valve is in both the fully open and fully closed positions. The spring applies maximum torque when the ball valve is in the fully open or fully closed position to ensure the valve remains in the fully open or fully closed position.

The driving mechanism has a tubular housing coupled to a control valve and housing an activating cylinder and an activated cylinder, cooperating with each other and respectively coupled to a rod of a wheel and a sealing device. The driving mechanism presents: an inoperative condition, in which the activated cylinder is maintained in a closing position of the control valve; a first operative condition, obtained by the rotation of the activating cylinder in a first sense and in which the activated cylinder is maintained in a first opening position, until the activating cylinder is rotated in an opposite sense, returning the activated cylinder to its closing position; and a second operative condition, obtained by rotation of the activating cylinder in a second sense and in which the activated cylinder reaches a second opening position, from which it is automatically displaced back to its closing position, in a timed manner.

The engine shut-off valve system includes a housing, a gate member, a rotating lever, a locking piston assembly, and a closing piston assembly. The system is installed in fluid connection with a flow line so that air flow passes through a passageway in the housing with the gate member in the locked configuration. The air flow through the passageway stops with the gate member in the closed configuration. The gate member has an asymmetry so that the forces of the spring of the closing piston assembly and the spring of the locking piston assembly are cooperative to actuate between the closed configuration and the locked configuration, while wearing on the gate member differently so as to extend the working life of the valve system. The closing piston assembly and the locking piston assembly are separately accessible for maintenance.

A control mechanism locks open a spring-loaded valve and automatically releases the spring-loaded valve to close upon a predetermined lesser weight load being applied. The spring-loaded valve includes a flow valve, a valve lever that pivots between open and closed positions, and a valve spring that biases the valve lever to the closed position. The control mechanism includes a pivotal release lever having an engagement arm and an opposite load arm, and a release spring that biases the release lever from a blocking position with the engagement arm retaining the valve lever in its open position to a release position with the valve lever free to pivot past the engagement arm and to the closed position under the valve spring force. The load arm includes an additive-container support for a load of an additive fluid to be mixed with a carrier fluid whose flow is controlled by the valve.

A rotatable pressure relief valve assembly is provided. The assembly may comprise a butterfly valve, a spring actuator, and a diaphragm device having a flexible membrane. A linkage assembly may be provided with a first end and a second end, wherein the first end may be configured to engage with a terminal end of a piston of a spring actuator, and wherein the second end may be configured to engage with a latch arm of the diaphragm device. A pilot tube may be configured to transmit an inlet fluid pressure from the inlet side of the butterfly valve to the sealed chamber. The assembly may further comprise a buckling pin mechanism having a buckling pin. The diaphragm device may be configured to translate the inlet fluid pressure into a compressive force and to transmit the compressive force to the buckling pin, and the latch arm may be configured to disengage from the second end of the linkage assembly when the buckling pin has buckled.

A flapper valve includes a body having first and second end, and a flapper pivotably coupled to the body and movable between a closed position, where the flapper prevents fluid flow through the body, and an open position, where fluid flow is allowed through the body. A first torsion spring is coupled to the body at the second end and provides a spring arm that engages and urges the flapper to the closed position. A support beam is coupled to the body and includes an axial extension that extends axially past the second end. A closure beam having a first beam end is pivotably coupled to the axial extension and a second beam end is engageable with the flapper. A second torsion spring is coupled to the axial extension and engageable with the closure beam to urge the closure beam into engagement with the flapper.

A device for controlling the opening and the closure of a valve includes rotatable element configured to control the position of the rotary valve on the basis of its rotation in a direction or in the opposite direction; and a system that causes the rotation of the rotatable element and includes two antagonist feeder conduits that generate a linear motion. The rotatable element is shaped as a pulley and the system that causes the rotation further includes a wire anchored to the pulley and to the feeder conduits to cause the rotation in a direction or in the opposite direction of the pulley based on the application of a pre-determined traction on the wire obtained through the linear motion generated by the feeder conduits.

A fusible fire-proof emergency cut-off valve is provided. Two sides of a valve body are communicated with an outlet and an inlet, respectively. The inside of the valve body is rotationally connected with a rotating shaft. A valve plate is fixed to one side of the rotating shaft and is positioned at one end of the outlet. A control mechanism comprises a shifting fork box body, one side of the shifting fork box body is connected with a second cylinder, and the other side of the shifting fork box body is connected with a first cylinder. The other side of the rotating shaft is inserted into the shifting fork box body and fixedly connected with a shifting fork. The inside of the second cylinder is provided with a piston rod penetrating through the shifting fork box body and the first cylinder.

Embodiments of an equalizing device for use with a safety valve and a safety valve are provided herein. In one embodiment, the equalizing device includes at least a tubular having a central bore extending axially there through, the tubular having a ball seat. The equalizing device may further include a ball positioned proximate the ball seat, the ball configured to move from a first position engaged with the ball seat to a second position disengaged from the ball seat to equalize pressure across the safety valve, and an arced ring positioned radially outside the ball, the arced ring configured to keep the ball engaged with the ball seat when in the first position and maintain the ball radially outside the ball seat when in the second position.