A gas valve regulates the amount of gas needed to produce a consistent flow without any gas leaking. This type of valve is generally found on appliances that require gas, and the valve is important to the operation and safety of gas appliances.
A gas valve is used to control gas pressure and provide safety features. A gas burner is normally located under an appliance and the burner is used to ignite the gas. The valve controls the pressure of the gas and the amount supplied to the appliance. Controlling the pressure is required to avoid fires and explosions caused by too much pressure. If the pressure is not high enough, though, the appliance will not get the amount of ignited gas required for it to function properly.
Gas valves are also placed on appliances for safety reasons. The valve has the ability to detect whether gas is being heated. After the gas travels across the pilot light, the gas is ignited. The ignited gas has an increase in temperature that is detected by the valve. When a specific temperature is detected, the gas valve cuts off the supply. Reducing the supply helps prevent potentially lethal gas from escaping or lingering in the area.