US Patent 7524364 Method and apparatus for draining pneumatic systems

Methods and apparatuses for determining the condition of a pneumatic system air dryer are provided. An output of the pneumatic valve or of a conduit interconnected to the outlet of the pneumatic valve is positioned such that a discharge passed through the pneumatic valve while the valve is open is in view of an operator and/or is directed to a moisture sensor. Moreover, the discharge and/or an output device interconnected to the moisture sensor is in view of the operator while the operator is in a position to operate the pneumatic valve. An observation volume with a sight glass or window and/or a moisture sensor can be provided to facilitate the observation or detection of moisture or oil in the discharge.