Patent ID: 8887796

Claim:
A plate heat exchanger comprising a plurality of heat exchanger plates, which are provided beside each other and permanently joined to each other to form a plate package having first plate interspaces and second plate interspaces, wherein each heat exchanger plate has a heat transfer area, a first porthole area, a second porthole area, a third porthole area and a fourth porthole area, each porthole area surrounding a respective porthole defined by a porthole edge, wherein each heat exchanger plate extends along a main extension plane, wherein said heat transfer area and said porthole areas extend between a primary level at a distance from the main extension plane and a secondary level at a distance from and on an opposite side of the main extension plane, wherein each of the porthole areas comprises: an annular flat area located at one of the primary and secondary level, a set of inner portions disposed on the annular flat area and distributed along the porthole edge, the inner portions being displaced from the annular flat area and extending to the other of the primary and secondary level, and a set of outer portions distributed along the annular flat area at a distance from the inner portions and being displaced from the annular flat area and extending to the other of the primary and secondary level, wherein the outer portions of the first porthole area have a first relative peripheral position with respect to the inner portions of the first porthole area, and the outer portions of the fourth porthole area have a second relative peripheral position with respect to the inner portions of the fourth porthole area, wherein the outer portions of the second porthole area have the second relative peripheral position with respect to the inner portions of the second porthole area, and the outer portions of the third porthole area have the first relative peripheral position with respect to the inner portions of the third porthole area, wherein the first relative peripheral position includes a peripheral displacement in relation to the second relative peripheral position, and wherein the outer portions of each porthole area are uniformly distributed entirely around the respective porthole with an equal outer angular distance between adjacent outer portions.