VALVE STEM ASSEMBLY

摘要

VALVE STEM ASSEMBLY A valve stem assembly for a valve which utilizes stem packing material which is capable of creep throughout its effective life when subject to a predetermined axial load. The stem packing material is retained within the stem opening against an internal shoulder upon initial installation to produce the predetermined axial load thereon and the stem is capable of axial movement under normal valve operating pressure to cause a radially extending shoulder thereof to apply the predetermined axial load when the stem packing material becomes subject to creep at some time after initial installation.