Heat exchanger with manifold strengthening protrusion

A plate type heat exchanger having a plurality of stacked plate pairs made up of first and second plates. Each plate pair has opposed manifold members that form respective inlet and outlet manifolds for the flow of a first fluid through a first set of fluid channels formed by the plate pairs. The manifold members space the plate pairs apart to form a second set of transverse flow channels for the flow of a second fluid. A protrusion member is formed at an end portion of the plates and proximal to each of the manifold members and has a mating surface, such that the protrusion members on the second plate of one plate pair align and abut with the protrusion members on the first plate of an adjacent plate pair thereby reinforcing and strengthening the manifold region of the heat exchanger to prevent deformation of the manifold under pressure.