A plate heat exchanger and a heat exchanger plate for evaporation of a first fluid are disclosed. The heat exchanger plate comprises a heat exchanger area extending in parallel with an extension plane of the heat exchanger plate and comprising a corrugation of ridges and valleys. An edge area extends around the heat exchanger area. Portholes extend through the heat exchanger area and comprise a first inlet porthole for said first fluid. A peripheral rim surrounds the first inlet porthole and extends transversely to the extension plane from a root end to an edge. The peripheral rim has a circumferential length and comprises a flat or substantially flat portion. A restriction hole extends through the flat or substantially flat portion.