Hazardous gas protection system and method for automatic valve closure

A hazardous gas protection system for installation on a fluid pipeline having a rotatable valve for interaction with the valve and to provide a warning upon detection of hazardous gas, the protection system comprising in combination:

• a system circuitry having a self-contained power source, a hazardous gas detection means to energize the system upon detection of a hazardous gas, and an actuation means that generates a linear force when the system is energized, said actuation means including a low pressure alarm means;
• a valve rotation means in articulation with the rotatable pipeline valve, that converts said linear force to a rotation torque force on the rotatable valve, whereby the pipeline valve is automatically rotated for automatic valve closure upon detection of a hazardous gas by the system;
• and,
• the system circuitry further comprising a warning signal means in communication with the hazardous gas detection means, whereby the system provides a warning of the presence of a hazardous gas while closing the valve.

A valve actuation system for use with a standard gas pipeline cock valve of a type having open and closed positions, with a normally open position, and an integral valve stem operable by a quarter of a turn thereof to close the valve, the system adapted for detection of hazardous gas, to provide an alarm for the detection of hazardous gas, and to automatically shut off a pipeline fluid flow by valve closure, the system comprising:

• a frame member mounted on a pipeline having a gas cock valve for terminating a fluid flow in the pipeline, the frame positioned over the valve thereof;
• a valve rotation means secured to the frame member and in articulation with a valve stem;
• a valve system circuitry having an actuation means in communication with the valve rotation means, a detection means in communication with the actuation means for generating an output signal to the actuation means, and a power source for energizing the circuitry;
• wherein the power source is a self-contained, integral power source that is independent from any other external power sources, comprising a rechargeable battery for supplying electrical power to operate the system, with a trickle charger adapted to maintain a charge on the rechargeable battery;
• wherein the detection means comprises a first detector having sensors for identifying smoke and fire and to provide an output signal for the hazard detected;
• and a second detector having sensors for identifying hazardous gases including carbon monoxide, propane, methane, and hydrogen, and to provide an output signal for the hazardous gas detected;
• the first and second detectors are in parallel in the system circuitry;
• further comprising first and second relays in communication respectively with the first and second detectors on the system circuit, the first and second relays adapted for closure to energize the circuit consequent to a detection means output signal;
• wherein the valve system circuit further comprises a first alarm means adapted to receive the detection means signal upon closure of the first relay, for output of a plurality of alarm signals in connection with detection of a hazardous gas, the plurality of alarm signals comprising a video signal and further comprising an audio signal;
• wherein the valve rotation means comprises a rotatable actuator shaft with upper and lower portions, the shaft secured on the frame by a shaft bearing near the upper portion and the lower shaft portion engaging the cock valve stem;
• a sprocket gear extending radially from the upper portion of the actuator shaft;
• a pneumatic cylinder fixed on the frame, the cylinder having a right, pull side and a left, push side, with a double action piston having a piston rod, the piston installed in, and normally positioned near the right, pull side of the cylinder, for providing a force necessary to rotate the valve;
• a container holding a pressurized gas in fluid communication with the cylinder right side;
• a link chain having first and second ends, the chain mounted on the sprocket gear with the first chain end anchored to the sprocket;
• a spring assembly attached to the second chain end and to the cylinder to apply a tension and retain the chain in position on the sprocket gear;
• the second chain end connected to the rod for coaction between the piston and the sprocket gear;
• and,
• a switch means in the circuit between the cylinder and the container, the switch means adapted to close by an output from the actuation means to complete the circuit, to impel pressurized gas into the right side of the cylinder and drive the piston toward the left side of the cylinder, with a consequent draw on the chain, thereby translating a linear force of the piston to a rotary motion of the sprocket gear, shaft and valve stem for closure of the valve.