Packing gland assembly

摘要

A packing assembly for a valve shaft or stem (8) consisting of inner and outer telescoping expander sleeves or rings (44, 46) slidably received intermediately in a stuffing box (32) between two groups of elastomeric sealing rings (F, G). Semi-fluid plastic sealing material is injected (60) between the expander rings to move them apart and thereby axially compress and radially expand the seal rings into sealing engagement with the stem or shaft and box wall. Portions of the plastic material pass through radial holes in the inner expander ring to form secondary seals within and about these rings.