Abstract: An exhalation valve arrangement includes an upstream breathing gas duct, which extends along a first duct path, a downstream breathing gas duct, which extends along a second duct path, and a valve assembly having a valve body and a valve seat, which valve assembly is provided such that, in the event of a predetermined first breathing gas overpressure in the upstream breathing gas duct relative to the downstream breathing gas duct. The valve assembly permits an exhalatory breathing gas flow from the upstream breathing gas duct to the downstream breathing gas duct and, in the event of a predetermined second breathing gas overpressure in the downstream breathing gas duct relative to the upstream breathing gas duct, the valve assembly blocks a gas flow from the downstream breathing gas duct to the upstream breathing gas duct.