摘要 |
A packing (10) for a stuffing box (12), for example, for petrochemical and/or power industry valves including one or more low density, graphite preform rings (30 and 44) which are further compressed, when the packing gland is tightened, with controlled material flow into the remaining open areas to provide impervious and effective I.D. and O.D. seals. The preform rings (30 and 44) are preferably adjacent higher density graphite adapter rings (32 and 46) with the adjacent facing surfaces (34-36 and 40-42) of the preform and adapter rings, preferably, having acute angles of 45 DEG and 60 DEG , respectively, with respect to the axis of the packing.
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