A metering valve helps control the flow of low to high viscosity fluids or gases in heavy equipment, such as cars and industrial equipment. The most commonly known types include brake metering valves and fuel metering valves, but there are also metering valves that control the flow of air. The sizes vary depending on use. Many metering valves are needle valves, but there are also chamber valves.
Needle valves have two separate compartments to decrease the chance of a leak. The liquid or gas enters the valve, travels through the needle valve and is dispensed out of the needle head. The chamber metering valve has a metering chamber that changes size based on the volume of the metered material. Another type of chamber valve, the cartridge chamber metering valve has a removable cartridge that allows for easy adjustment of chamber volume and easy valve repair. In this type of metering valve, the liquid or gas enters the cartridge chamber, travels through the metering chamber and is dispensed from the end of the needle head.
In a vehicle or truck, the metering valve works to help regulate the function of front disc brakes with rear drum brakes. The metering valve, usually located in the hydraulic lines, holds off the pressure released by the front brakes until the back brakes can exert force against the springs and begin to slow the motion of the vehicle. Without the metering valve, the back brakes don't work as quickly as the front brakes, causing the back end of the vehicle to be unstable. In some vehicles, a combination valve takes the place of a metering valve and houses all the valves necessary for proper operation.
Fuel metering valves are common in off-road vehicles and construction equipment that utilize diesel fuel. A fuel metering valve works much like the brake valve, except instead of metering the amount of pressure, it meters the amount of fuel released to the burner. Without the fuel metering valve, diesel machines would have fuel leaks and engine problems.
