Vallourec Deutschland (Düsseldorf, Germany):

J. Briselat, e-mail: julian.briselat@vallourec.com
Ch. Bem
T. Walther
G. Pereira

During the last years Vallourec has often met the restrictions connected with operation of the old piercing mill. At the same time piercing mill is an important factor of providing flexibility of the whole pilger line, meaning possibility to manufacture the same tube from billets of different diameter. Thereby it was decided to put into practice the principally new up-to-date piercing mill. The corresponding investments were planned in accordance with three requirements: improvement of labour safety and environment protection; rise of production efficiency as well as improvement of products quality and delivery terms; strategic adaptation of the pilger line. The main technological feature of the new piercing mill is symmetric location of driven work rolls with the same size. It provides, firstly, symmetric deformation conditions, and secondly, exact and geometrically independent orientation of the roll gap relating to the constant axial rolling line. Vallourec succeeded to realize this reconstruction project, including dismantling of the old piercing mill, renovation of the base, mounting of the new piercing mill, drives, hydraulic, electric and automation systems, during less than 10 weeks.