Heat transfer plate

A heat transfer plate comprising an upper end part, a center part and a lower end part arranged in succession along a longitudinal center axis of the heat transfer plate, the upper end part comprising a first port hole area, an upper distribution area provided with a distribution corrugation pattern, and a first adiabatic area arranged between the upper distribution area and the first porthole area and provided with a first adiabatic corrugation pattern, and the center part comprising a heat transfer area provided with a heat transfer corrugation pattern, the heat transfer, the distribution, and the first adiabatic corrugation patterns differing from each other, the heat transfer plate further comprising opposing front and back sides and an outer edge portion comprising outer corrugations extending between and in first and second planes, which first and second planes are parallel to each other, the front and back sides of the heat transfer plate facing the first and second planes, respectively, wherein the first port hole area comprises a first port hole defined by an annular first port edge, an annular first ring gasket groove extending on the front side of the heat transfer plate around the first porthole, and an annular first port portion, which extends between the first ring gasket groove and the first porthole and includes the first port edge, wherein the first port edge consists of a first inner section and a first outer section, which first outer section is 35-80% of the first port edge and which first inner section extends between the first porthole and the first adiabatic area, wherein the first port portion comprises first inner port corrugations along the first inner section of the first port edge, wherein a bottom of the first ring gasket groove, along at least a major portion of the first inner section of the first port edge, extends in a third plane, and wherein the bottom of the first ring gasket groove, along at least a major portion of the first outer section of the first port edge, extends in a fourth plane, wherein at least a plurality of the first inner port corrugations extend between and in a first intermediate plane and the second plane, which first intermediate plane extends between the first and second planes, wherein the third plane and the first plane extend on opposite sides of the first intermediate plane.