The temperature control valve controls the lubricating oil entering the oil cooler to ensure the rotor temperature is within the desired level. Filters are an important part of your compressed air system. Installing the right type of filters and maintaining them regularly will ensure a consistent supply of clean air to your operations and reduce pressure drop. Filters start at the intake of the compressor and finish at the point of use. http://www.vimce.net/air-compressor-intake-valve/air-compressor-solenoid-valve/