MSS SP-143
MSS SP-143 2012-JAN-01 Lve-Loaded Valve Stem Packng Systems
This Standard Practice establishes the minimum requirements for the application, design and installation of live-loaded stem packing systems for valves designed in accordance with ASME B16.34, having rising and/or rotating stems. It applies to valves with flexible graphite, polytetrafluoroethylene (PTFE), or other packing stem seal material, regardless of frequency of operation.
This Standard Practice does not apply to valves that include a lantern ring(s) as part of its packing system or to self-energized packing