SRZ type radiator is divided into three types: large (D), medium (Z), and small (X) according to the heat dissipation capacity. The fin tubes of the radiator are all made of φ21x2m/m and 15x0.5m/m steel strips are wound on the non-sealing steel. They are in a spiral shape. The distance between the fins is 5mm--large D, 6mm-- There are three kinds of medium Z, 8mm-small X, with a total of 38 specifications.