Patent ID: 7828014

Claim:
A heat exchanger comprising: a heat exchange element including an inlet manifold, an outlet manifold and a plurality of fluid paths each extending between the inlet manifold and the outlet manifold; a main body part including: a first plate operatively permanently secured to the heat exchange element and having extending therethrough a valve orifice communicating with one of the inlet manifold and the outlet manifold; and a transverse pin spaced from the valve orifice and extending from the first plate to an enlarged upper head part, the pin being secured to the first plate in a manner such that an unbroken sealing surface of the main body part seals, but for said valve orifice, said one of the inlet manifold and the outlet manifold; and a flexible flapper valve having: a mounting end portion defining a hole through which the pin extends, the flapper valve being retained in position against the first plate by the enlarged upper head part; a free end portion movable from a first position, where the free end portion at least partially blocks flow through the valve orifice, to a second position spaced from the valve orifice; and bias means for urging the free end portion into the first position.