Graphite Gland Packing
Product Description This type of gland packing is made from graphite-PTFE compound with lubricant and has very good thermal conductivity. It has high flexibility and volumetric..
- Self-lubricating & highly heat-conductive — runs cool
- Chemically resistant across the full pH 0–14 range
- Flexible with high volumetric stability — seals and stays sealed
- For rotating pumps and valves to ~450°C
Overview
Graphite gland packing is the general-purpose high-temperature packing for rotating pump shafts and valve stems. It is braided from flexible graphite yarn — here a graphite/PTFE compound with lubricant — and its defining feature is that it seals hot, fast-moving shafts without burning up the way a fibre packing would. Graphite is self-lubricating and an excellent conductor of heat, so it carries frictional heat away from the shaft and runs cool where organic packings would carbonise.
Two properties make it dependable in service. First, its very high thermal conductivity means it does not build up a hot spot at the shaft, which protects both the packing and the shaft sleeve. Second, its flexibility combined with high volumetric stability means it conforms to the stuffing box to make the initial seal, then holds that seal without shrinking or hardening over time — so it does not need constant re-adjustment. It is also chemically resistant across essentially the whole pH range, from strong acids to strong alkalis.
On rotating equipment this grade is rated to around 450°C, which covers the great majority of hot pump and valve duty in a plant. It suits water, steam, oils and a wide range of chemical media. Because graphite is soft, it is gentle on the shaft — an important point on expensive pump sleeves.
One thing to specify correctly: for the most extreme high-pressure valve stems — superheated steam and boiler isolation valves — you want the Inconel-reinforced grade, our Graphite Packing with Inconel Wire, where a metal reinforcement stops the soft graphite extruding under several hundred bar. This standard graphite grade is the right choice for rotating pumps and general valve duty. Sizes run from 3 mm to 25 mm square; our gland packing calculator will size it for you.
Specifications
Typical properties of flexible graphite gland packing for rotating and general valve duty. The Inconel-reinforced grade is a separate high-pressure valve product.
| Property | Value | Test Standard |
|---|---|---|
| Material | Flexible graphite yarn (graphite/PTFE, lubricated) | — |
| Max Temperature — Rotating | ~450°C | — |
| pH Range | 0 – 14 (except strong oxidisers) | Full range |
| Thermal Conductivity | High — carries heat off the shaft | — |
| Self-Lubricating | Yes | Runs cool |
| Volumetric Stability | High — holds the seal without re-adjustment | — |
| Shaft Wear | Low — soft, gentle on the sleeve | — |
| Media | Water, steam, oils, chemicals | — |
| Standard Sizes | 3 mm – 25 mm square | — |
| For High-Pressure Valves | Use Inconel-reinforced grade | See cross-link |
Applications
The general graphite packing for hot rotating pumps and valves.
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Frequently Asked Questions
What is the difference between this and graphite packing with Inconel wire?
This standard graphite grade is for rotating pumps and general valves to around 450°C. The Inconel-reinforced grade is for extreme high-pressure valve stems (superheated steam, boiler isolation) — the wire stops the soft graphite extruding under several hundred bar. Match the grade to the duty.
What temperature can it handle?
Around 450°C on rotating equipment, which covers most hot pump and valve duty. Graphite is self-lubricating and highly heat-conductive, so it runs cool where a fibre packing would carbonise.
Is it chemically resistant?
Yes — graphite is resistant across essentially the whole pH range, from strong acids to strong alkalis. Its one real weakness is strong oxidising agents, and oxidation in air above roughly 450°C.
Will it damage my pump shaft?
No — graphite is soft and self-lubricating, so it is gentle on the shaft sleeve. That, plus its heat conductivity, is why it is preferred on expensive rotating equipment.
How do I size it?
Packing size = (stuffing box bore − shaft diameter) ÷ 2, in a square section from 3 mm to 25 mm. Our gland packing calculator works it out and totals the metres you need.
Does it need frequent re-adjustment?
Less than most packings — its high volumetric stability means it holds the seal without shrinking or hardening, so it does not need constant re-tightening once bedded in.
Need a quote or a spec check?
Send us your operating conditions and we will confirm the right grade for the job.
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