A plate and frame heat exchanger is a compact heat exchanger where thin corrugated plates are stacked in contact with each other, and the two fluids flow separately along adjacent channels in the corrugation. The closure of the stacked plates may be by clamped gaskets, brazed (usually copper brazed stainless steel), or welded (stainless steel, copper, titanium), the most common type being the first, for ease of inspection and cleaning
