Pneumatically controlled drain valve

A drain valve for a cooler of a compressor, with a pressure chamber which is connectable to the interior space of a cooler via a connecting opening, and an outlet opening for removing a condensate, the drain valve comprising:

• a pneumatic switching device including a membrane;
• and
• a nonreturn valve, wherein the nonreturn valve and the pneumatic switching device are operatively connected to the pressure chamber,
• wherein there is an operative connection between the pneumatic switching device and the nonreturn valve by which the nonreturn valve is switchable by the switching device into an open position, and
• wherein, in an idle mode of the compressor, the nonreturn valve is switchable by the switching device into the open position such that condensate is removed from the connecting opening through the outlet opening via the nonreturn valve, and
• wherein in the open position in the idle mode a tappet of the pneumatic switching device is configured to move into contact with the nonreturn valve to move the nonreturn valve towards the outlet opening, allowing a fluid to flow around the pneumatic switching device and into the outlet opening,
• wherein the non-return valve includes a valve element with a plurality of projections extending outwardly from the element to guide the element in the valve housing, and providing openings between the plurality of outwardly extending projections for air and condensate to flow between.