All welded plate heat exchanger

The invention relates to an all-welded plate heat exchanger comprised of a plurality of plates welded together to form cassettes that are stacked one upon the other so as to provide primary and secondary alternating channels through which fluids are adapted to flow for exchanging heat. The primary channels provided within the cassettes connect at opposite ends with inlet and outlet openings The cassettes are welded along two opposing sides via resistance seam welding. Baffle clips are fastened between the cassettes to partially close off the sides of the secondary channels provided between the cassettes. Two inlet headers, two outlet headers, a top cover member and a bottom cover member enclose the stacked cassettes.