Patent ID: 8662151

Claim:
A heat exchanger plate for plate heat exchangers comprising a heat transfer area, an edge area that extends around and outside the heat transfer area, and a number of portholes that extend through the heat exchanger plate and are located inside and in the proximity of the edge area, the porthole being defined by a porthole edge and having a center, the porthole edge having a first edge portion adjacent to the edge area, and a second edge portion adjacent to the heat transfer area, the second edge portion extending over a circumferential extent from one circumferential end of the second edge portion which is adjacent the heat transfer area to an other circumferential end of the second edge portion which is adjacent the heat transfer area, and wherein the first edge portion has a corrugation seen from the center of the porthole, and the second edge portion has a substantially plane shape seen from the center of the porthole, the substantially plane shape of the second edge portion extending continuously throughout the circumferential extent of the second edge portion.