25% carbon powder PTFE tube for sealing

For critical sealing applications where dimensional stability and low friction are not optional, specifying a carbon powder filled PTFE tubing grade is one of the most cost-effective upgrades available. The 25% carbon filler reduces creep and cold flow under compressive load, which keeps the seal face square over extended service intervals. Engineers looking for a fine carbon PTFE tube high wear solution typically select this material for reciprocating shafts, valve stems, and rotary unions where abrasive media or boundary lubrication is present. As an established 25% carbon PTFE tube manufacturer, we control particle size distribution and sintering parameters to produce a dense, uniform tube wall without voids, cracks, or carbon agglomeration. The same product is frequently supplied as a carbon powder PTFE tube for hydraulic cylinder sealing, where high-pressure fluid compatibility and low breakout friction are essential. Compared with bronze-filled compounds, the carbon-filled version is softer on mating metal surfaces and performs better in water, mild acids, and oxidizing environments where bronze can corrode. Because the material is non-porous and chemically resistant, it seals aggressively against fuels, refrigerants, and most process fluids without swelling or embrittlement.

The 25% Carbon Powder PTFE Tube for Sealing is produced from 100% virgin PTFE resin and high-purity carbon powder, blended at a nominal 25% by weight. The carbon dispersion is verified microscopically on every production lot, which keeps the tube wall homogeneous and prevents localized soft spots or filler-rich bands. In sealing service, this uniformity matters because uneven carbon distribution can create preferential wear paths and reduce the effective life of a lip seal or backup ring. The product is black in appearance and has a slightly higher specific gravity than unfilled PTFE, a direct indication of proper filler loading. For fabricators, the tube can be supplied in continuous coils or straight lengths, then cut, skived, or machined into finished sealing elements. Dimensional control is held to tight tolerances because seal grooves demand consistent wall thickness and roundness. All standard measurements are verified with calibrated digital gauges, and lot traceability is maintained from raw resin to final packaging. The values below are obtained from laboratory samples conditioned at 73°F (23°C) and 50% relative humidity, and each batch is tested for tensile strength, elongation, and specific gravity before release.

• Composition: 75% virgin PTFE + 25% carbon powder by weight
• Color: black, uniform across the wall
• Available inner diameters: 0.078 in to 3.937 in (2 mm to 100 mm)
• Available wall thicknesses: 0.020 in to 0.500 in (0.5 mm to 12.7 mm)
• Standard lengths: 1 m, 2 m, 3 m cut pieces; coils up to 328 ft (100 m)
• Roundness tolerance: 0.002 in (0.05 mm) for diameters up to 1 in; 0.004 in (0.10 mm) above 1 in
• Wall thickness tolerance: ±0.0012 in (±0.03 mm) for wall ≤0.080 in; ±0.002 in (±0.05 mm) for wall >0.080 in
• Surface finish: Ra 0.4–0.8 µm on machined contact faces
• Continuous service temperature: -328°F to +500°F (-200°C to +260°C)
• Chemical resistance: unaffected by most solvents, acids, alkalis, and hydraulic fluids
• Storage: keep away from direct sunlight and dust; no special temperature control required