GRAPHITE DISC RUPTURE DISCS MADE PREDOMINATELY OF GRAPHITE. THE DISCS ARE FOR USE IN VARIOUS TYPES OF TUBING/VESSELS/EQUIPMENT. THEY OPEN WHEN OVER PRESSURE OCCURS, THUS PROTECTING THE EQUIPMENT FROM DAMAGE CAUSED BY EXCESS VACUUM OR PRESSURE. THE DISCS ARE OF VARIOUS DIMENSIONS

GENERAL INTERPRETATIVE RULES 1 & 6 HARMONISED SYSTEM EXPLANATORY NOTES TO HEADING 6815 NOTES TO HEADING 68 AND 6815 10 90