Plate & frame heat exchanger is composed of heat transfer plates (corrugated metal plates) which are sealed by gaskets, tightened together by tie rods with locking nuts between frame plate. The port holes on the plate form a continuous flow path, the fluid runs into the path from inlet and is distributed into flow channel between heat transfer plates. The two fluids flows in counter current. Heat is transferred from hot side to cold side through heat transfer plates, the hot fluid is cooled down and the cold fluid is warmed up.