The heat exchangers are constituted by a pack of heat exchange plates of material suitable with the fluids that need to exchange heat, held together by a brazing realized in different types of material (copper, nickel, stainless steel).The plates constitute two channels, one for the hot fluid which transfers heat to the other, and one for the cold that receives the heat. The brazed plate heat exchanger presents the main advantage of the compactness, since it is consisting only of the plate pack, definitely lower in size and weight than a similar heat exchanger equipped with the inspectable frame.