Safe casing

A safe casing, comprising:

• a casing having an open space formed in a side thereof, the open space having a first chamber with a first gas intake, a second gas intake and an gas outlet, and a second chamber adjacent to the first chamber;
• two solenoid valves device installed in the first chamber of the open space, and respectively being a main solenoid valve device and an auxiliary solenoid valve device;
• a control circuit device installed in the second chamber of the open space;
• and
• a sealing means for sealing said casing after the solenoid valve devices and the control circuit device are respectively installed in the open space, the sealing means having a permanent cover covering said open space of said casing;
• wherein the main solenoid valve device controls opening and closing of the gas outlet installed in said casing, and as closing, the second gas intake installed in the casing is unable to take gas;
• wherein the auxiliary solenoid valve device controls opening and closing of the first gas intake installed in said casing, and as opening, the gas flow rate of said gas outlet is able to be increased relatively;
• wherein the gas is output from the gas outlet only when the first gas intake goes through the limitation that the main solenoid valve device and the auxiliary solenoid valve device are open simultaneously.