MANUFACTURE OF INSULATED PIPE JOINT AND INSULATED PIPE JOINT MANUFACTURED BY THIS METHOD

摘要

PROBLEM TO BE SOLVED: To keep stable gas sealing and electric insulation for a long time by providing a joint ring projecting to an alumina ring side on a flange surface and jointing the alumina ring and a joint ring by brazing. SOLUTION: Ni plating 14 and Mo-Mn metallization layer are applied on a joint ring 12 and an alumina ring 11 respectively, so as to improve the brazing. The alumina ring 11 is fitted in the flange 10F and the joint ring 12. The joint ring 12 and the alumina ring 11 are integrated by a molten brazing material 13. The joint ring 12 is contracted in the temperature lowering process of the brazing and compressive stress C of the joint ring 12 is applied on the alumina ring 11, however, the alumina ring 11 is so thick as to sufficiently endure it. After the alumina ring 11 and the joint ring 12 are jointed together, the flange 10F is welded to the joint ring 12 to form an insulated flange. The insulated flange leaves the compressive stress C at 1100 deg.C or less so as to keep superior sealing.