Abstract: Valve for controlling the flow of gases under high pressure from storage vessels such as cylinders comprising a solenoid operated pilot valve built into the valve body and operable to cause a floating piston to actuate a main valve stem by moving against a shoulder on said stem, there being a clearance between a seat for said piston and said shoulder to permit the introduction of a safety pin or fork to lift and immobilize the piston to avoid its acting under pressure and causing accidental discharge.