Redundant gas valves are a popular category of gas valve, which controls the passage of gas to the burner in a gas furnace or other gas-fueled equipment. Redundant gas valves are designed to ensure utmost safety.
The central design feature of redundant gas valves is the valve's two or three valve operators, which are located in series to each other but wired in parallel to each other, according to the 2009 book, "Practical Heating Technology." Those multiple operators, which are the valves' redundancies, are the common element of different types of redundant gas valves.
The redundant gas valve arrangement means that either the pilot valve operator or the main valve operator can shut off the flow of gas to the main burner. That redundancy creates more options and possibilities for keeping gas from reaching the burner when necessary.
There are three types of redundant gas valves. They are the standing pilot, the intermittent pilot and the direct burner. Each is a widely used form of gas valve.