Multi-circuit protection valve for an air treatment system

The multi-circuit protection valve has overflow valves, where each valve has a valve seat (35) and a membrane area adjacent to the valve seat. A valve housing (31) is provided, in which the valve output lines of the overflow valves are formed. A supply chamber is formed in the valve housing as a pressure air supply to the overflow valves. The supply chamber has a recess (34) formed in the valve housing, where the recess surrounds the valve seat. An independent claim is included for an air treatment plant with an air dryer cartridge.