API std 622 3rd Edition Graphite Packing for Valves. Carrara has enriched the certification's level of its Valve Gasket achieving the certification API std 622 3rd Edition. The graphite packings PGT3 GR8622 and PGT4 GR8622, special sealing for Low Emission Service Industrial Valves, have been tested and approved API 622, made with the graphite Gland Packing GR8622 suitable for the maintenance on-site. This result allows to improve the supply of high performance graphite packings to compete at the highest levels of this specific field.