Patent ID: 7104315

Claim:
A heat exchanger plate for a plate heat exchanger, having at least a first area with a corrugation of ridges and valleys, the plurality of which extends in a first direction, the plate having a central rotary axis (x) which extends in parallel with a normal line of the plate, and the plate including at least a second area with a corrugation of ridges and valleys, the plurality of which extends in a second direction, said first and second areas having a respective contour, coinciding with a respective imaginary stationary contour in a first rotary position of the plate with regard to said rotary axis (x) and after a rotation of 90° to a second rotary position of the plate with regard to the rotary axis (x), wherein the plate has an edge, which extends around the plate, and an edge area, which extends around the plate inside the edge, and is substantially square and has four side edges and four corners, wherein first two of said side edges are parallel and folded in a first direction along a respective folding line extending in said edge area in parallel with the side edge in question, wherein second two of said side edges are parallel and folded in a second direction along a respective folding line extending in said edge area in parallel with the side edge in question, and wherein the first direction is opposite to the second direction.