Two-stage solenoid safety gas valves of the VSX series are suitable for shut-off of combustible gases of the first, second and third family. Versions for air and biogas are available on request. These solenoid valves, normally closed for continuous and cyclic operation, open when the coil is energised and close rapidly on power failure. There are two stages of fluid regulation, the first through the lower coil, the second through the upper coil or the valve is fully open when both coils are energised. VSA valves conform to EN161 with CE certification.