Graphite sealing rings outperform metal and elastomeric seals in high-temperature, high-pressure, and chemically aggressive environments. As a graphite sealing ring supplier in India, Expo Advanced Materials machines precision rings from dense, low-porosity graphite grades suitable for valves, pumps, compressors, furnace door seals, and rotating shaft seals across industries.
Why Graphite for High-Temperature Sealing?
- Self-lubricating — Graphite requires no external lubrication, eliminating lubricant degradation as a failure mode at high temperature.
- Chemical resistance — Resistant to most acids, alkalis, and organic solvents. Compatible with steam, hot gases, molten metals, and process chemicals.
- Temperature range — Up to 450 °C in air, up to 3,000 °C in inert or vacuum atmospheres.
- Dimensional stability — Low coefficient of thermal expansion (3–5 × 10⁻⁶ /°C) maintains seal geometry through thermal cycling.
- Low friction — Coefficient of friction 0.1–0.2 against stainless steel, reducing actuator torque and seal wear.
Sealing Ring Grades
| Grade | Density (g/cm³) | Max Temp (air) | Best Application |
|---|---|---|---|
| Electrographite seal grade | 1.60–1.70 | 400 °C | Steam valves, pump shaft seals |
| Isostatic graphite | 1.75–1.88 | 450 °C in air; 3,000 °C vacuum | Vacuum furnace door seals, precision valves |
| Resin-impregnated graphite | 1.75–1.85 | 200 °C | Liquid pumps, chemical process seals |
| Anti-oxidation coated | 1.78–1.85 | 700 °C in air | High-temperature air-exposed furnace seals |
Dimensions We Machine
- OD range: 15 mm to 1,200 mm (larger on request)
- ID range: 10 mm upward (wall thickness minimum 3 mm for small rings)
- Height/thickness: 5–200 mm
- Tolerances: OD and ID to ±0.05 mm; flatness to 0.02 mm per 100 mm diameter
Industries and Applications
- Glass industry — Furnace flue valve seats, feeder tube seals
- Chemical process — Pump mechanical seals, reactor agitator shaft seals
- Power generation — Steam valve disc seals, turbine packing rings
- Vacuum furnaces — Door frame seals, feedthrough seals
- Semiconductor — Process chamber seals, gate valve components
How to Order
Provide OD, ID, height/thickness, graphite grade or application temperature, and quantity. For critical sealing applications, share the mating surface material and surface finish — we recommend the optimum graphite grade. Pricing and availability confirmed within 24 hours.