Abstract: A solenoid valve has a main body defining a gas inlet passage, a gas outlet passage, and a cavity; a core tube forming a closure for said the cavity so as to prevent an escape of gas; a cylindrical main piston slidably movable in said the cavity of said the main body, said the main piston forming a front chamber and a back chamber in said the main body, said the main piston having a gas conduit for passing the gas from said the gas inlet passage to said the front chamber and an axial hole for passing the gas from said the back chamber into said the gas outlet passage with a bleed orifice at one end of said the axial hole; said the main piston being spring biased to a closed position; a spring biased pilot piston; and an electrical coil means associated with said the core tube to provide a magnetic field for movements of said the pilot piston and said the main piston, so that when said the coil means is deenergized said the pilot piston closes said the outlet passage and causes a pressure equalization allowing