Pressure gas release valve for fire suppression

1. A two-step, self-regulating valve for controlling gas flow from a gas cylinder in high pressure systems, the valve comprising:

a valve body;

a piston movable within the valve body along an axis between a first and a second position;

a plug movable within the valve body along the axis between a valve closed position, a partially open position, and a fully open position;

a valve actuator that allows the plug to move from the valve closed position to the partially open position; and

a piston actuator that causes the piston to move from the first position to the second position when a gas pressure in the gas cylinder is less than a setpoint to allow the plug to move from the partially open position to the fully open position.

2. The two-step, self-regulating valve of claim 1 , wherein the valve body has an interior cavity, the interior cavity having a first end and a second end.

3. The two-step, self-regulating valve of claim 2 , and further comprising a bias chamber located in the first end of the interior cavity and a control chamber located in the second end of the interior cavity.

4. The two-step, self-regulating valve of claim 3 , and further comprising a flow passage connecting the gas cylinder, the bias chamber, and the control chamber.

5. The two-step, self-regulating valve of claim 4 , and further comprising a bleed passage connected to the bias chamber, wherein the gas pressure is vented to the atmosphere through the bleed passage.

6. The two-step, self-regulating valve of claim 4 , and further comprising a slidable spool engageable with the bleed passage and slidable between a closed position and an open position.

7. The two-step, self-regulating valve of claim 3 , wherein the plug is urged towards the partially open position by a decreasing pneumatic pressure in at least one of the chambers.

8. The two-step, self-regulating valve of claim 3 , wherein the piston actuator is a spring and wherein the piston is urged towards the second position by a decreasing pneumatic pressure in at least one of the chambers and the spring.

9. The two-step, self-regulating valve of claim 3 , wherein the plug engages the piston when the plug is in the partially open position, and wherein the piston moves to the second position and the plug moves to the fully open position simultaneously as a function of a decreasing pneumatic pressure in the control chamber.

10. The two-step, self-regulating valve of claim 1 , wherein a rate of gas release from the self-regulating valve is based on a contour of the plug.

11. An open loop pneumatic flow control valve for controlled gas pressure release from a gas cylinder in a protected room, the open loop pneumatic flow control valve comprising:

a valve body;

a piston movable between a first position and a second position within the valve body;

a plug movable between a closed position, a partially open position, and a fully position within the valve body; and

an activation device;

wherein the plug moves from the closed position to the partially open position in response to activation of the activation device, and wherein the plug moves from the partially open position to the fully open position and the piston moves from the first position to the second position in response to a decreasing pressure in the gas cylinder.

12. The open loop pneumatic flow control valve of claim 11 , and further comprising a bias chamber and a control chamber located within the valve body.

13. The open loop pneumatic flow control valve of claim 12 , and further comprising a flow passage connecting the gas cylinder, the bias chamber, and the control chamber.

14. The open loop pneumatic flow control valve of claim 13 , and further comprising a bleed passage for venting gas pressure from the bias chamber to the atmosphere.

15. The open loop pneumatic flow control valve of claim 14 , wherein the plug is urged from the closed position to the partially open position by a decreasing pneumatic pressure in the bias chamber.

16. The open loop pneumatic flow control valve of claim 15 , wherein the plug is urged from the partially open position to the fully open position and the piston is urged from the first position to the second position by a decreasing pneumatic pressure in the control chamber.

17. The open loop pneumatic flow control valve of claim 11 , and further comprising a primary passage connecting the gas cylinder to the atmosphere, wherein the primary passage opens progressively from a minimal to a maximal area as the plug moves from the closed position to the partially open position and from the partially open position to the fully open position.

18. A method for automatically releasing gas from a gas container into a pipe in two phases, the method comprising:

actuating an actuation device connected between a valve body and a bleed passage;

moving a plug from a closed position to a partially open position in response to a first pneumatic pressure differential between the valve body and the pipe; and

urging a piston from a first position to a second position, and urging the plug from the partially open position to a fully open position in response to a second pneumatic pressure differential between the valve body and the gas container.

19. The method of claim 18 , wherein urging the piston to the second position is further in response to a spring.

20. The method of claim 18 , wherein the actuation device is a slidable spool.

21. The method of claim 18 , wherein the actuation device is a Schraeder valve.