Sealing & Emission Control Systems
Stem Sealing
Flexible Graphite Packing System
Die-formed flexible graphite rings replace older fibre/PTFE packing sets, giving stable sealing across a far wider temperature range with lower fugitive emission by design.
How does flexible graphite packing system work?
Graphite's laminar structure conforms to the stem and stuffing-box bore under gland compression while resisting extrusion at high temperature and remaining chemically inert to most process fluids - a direct material response to the emission-control push that made older fibre packings obsolete for critical service.
When to Use It
- High-temperature steam and hot-oil service where fibre or PTFE packing degrades
- The default upgrade path when re-packing an older valve to meet current fugitive-emission expectations
- Combined with a live-loaded gland for the strongest standard-packing emission performance available
Limitations
- Can promote galvanic corrosion against certain stainless stems if not isolated - inhibited grades address this
- Requires correct gland torque; over-compression increases stem operating torque unnecessarily
Typical MaterialsFlexible graphite (die-formed rings); Corrosion-inhibited graphite grades for stainless stems
Governing Standards
Related Failure Mechanisms
Related Troubleshooting Guides
Typically Specified In
Other stem sealing designs
Reviewed by Process Engineering, Vajra Industrial SolutionsDiscipline: Valve Service SpecificationLast reviewed: 20 June 2026
Connected Engineering
Failure Modes
Need valves with flexible graphite packing system?
We supply Gate Valves / Globe Valves with flexible graphite packing system to ISO 15848-1, with full certification. Get a 24-hour quote.
Relevant Products