Graphite PTFE Packing represents a significant advancement in sealing technology, combining the unique properties of PTFE (Polytetrafluoroethylene) and flexible graphite. This engineered material is designed to handle extreme conditions where traditional packings fail. By integrating the chemical inertness and low friction of PTFE with the excellent thermal conductivity and resilience of exfoliated graphite, this packing offers superior performance in a wide range of demanding applications. It is a premium solution for sealing pumps, valves, agitators, and other rotary or reciprocating equipment, ensuring long-term reliability and minimizing maintenance downtime. At Kaxite Sealing, we have refined this composite material to meet the highest industrial standards, providing a robust seal that withstands aggressive media, high temperatures, and varying pressures.
The synergy between PTFE and graphite creates a packing with unmatched characteristics. Below are the primary features and the direct benefits they offer to engineers and maintenance professionals:
To ensure proper selection and application, it is crucial to understand the detailed specifications of our packing. The following table outlines the standard parameters for Kaxite Sealing's Graphite PTFE Packing.
| Parameter | Specification / Value | Notes / Standard |
|---|---|---|
| Material Composition | PTFE Filament Impregnated with High-Purity Flexible Graphite | Core: PTFE, Jacket: Expanded Graphite |
| Temperature Range | -212°F to +600°F (-100°C to +315°C) | In oxidizing atmospheres, upper limit is 450°F (232°C) |
| pH Range | 0 - 14 | Resistant to virtually all acids, alkalis, and solvents |
| Density | 1.8 - 2.2 g/cm³ | ASTM D3800 |
| Tensile Strength | ≥ 12 MPa (min) | ASTM D2256 |
| Compression Recovery | > 40% | ASTM F36 |
| Thermal Conductivity | 5 - 10 W/m·K | Through-plane |
| Coefficient of Friction | 0.05 - 0.10 (dynamic) | Against polished stainless steel |
| Maximum Shaft Speed | Up to 25 m/s | Dependent on gland design and lubrication |
| Pressure Rating | Up to 2500 psi (172 bar) | For rotary applications; higher for static seals |
| Available Forms | Spooled Cord, Die-Formed Rings, Coils | Standard sizes from 1/8" to 1" (3mm to 25mm) cross-section |
| Standard Colors | Black (Graphite), White (PTFE), or Gray Blend | Custom colors available upon request |
Selecting the correct cross-sectional size is vital for effective sealing. Use this quick-reference list for common shaft diameters.
Note: For reciprocating rods, the recommended cross-section is typically 1.5 times the radial clearance.
Kaxite Sealing's Graphite PTFE Packing is trusted across diverse sectors due to its versatility and durability.
Correct installation is key to maximizing the service life of your graphite PTFE packing. Follow these steps for best results:
Q: What makes graphite PTFE packing superior to traditional asbestos or aramid fiber packings?
A: Graphite PTFE packing offers a combination of advantages that older materials lack. It provides broader chemical compatibility, higher temperature tolerance, and superior thermal conductivity to manage frictional heat. It is self-lubricating, reducing shaft wear and power consumption. Furthermore, it is non-toxic and environmentally safe, unlike asbestos. While aramid fibers are strong, they lack the chemical resistance and low-friction properties of PTFE/graphite composites.
Q: Can Kaxite Sealing Graphite PTFE Packing be used in food-grade applications?
A: Yes, absolutely. The PTFE used in our packing is a high-purity, FDA-compliant grade resin. The flexible graphite is also a clean, inert material. When manufactured under controlled conditions, the final product is suitable for use in food, beverage, and pharmaceutical processing where incidental contact is possible, provided it complies with local regulations and specific equipment validation requirements.
Q: How do I determine the correct number of packing rings to install in my stuffing box?
A: The general rule is to use a number of rings so that the total packed height is approximately 1.5 times the shaft diameter or the cross-sectional width of the packing, whichever is larger. A more precise method is to calculate: Number of Rings = (Stuffing Box Depth) / (Packing Cross-Section). Always leave a small clearance (about 10-15% of the box depth) for the gland follower to apply even pressure.
Q: Is external flushing or lubrication required with this type of packing?
A: In most standard applications with clean fluids, external lubrication is not necessary due to the material's self-lubricating properties. However, for extremely abrasive slurries, dry-running conditions, or aggressive chemicals that may crystallize, a compatible flush (lantern ring arrangement) is recommended to extend packing life, cool the shaft, and prevent solids ingress.
Q: What is the expected service life of this packing?
A: Service life varies significantly based on operating conditions: shaft speed, media abrasiveness, temperature, pressure, and installation quality. Under standard service conditions (clean water, moderate temperature/speed), you can expect 12 to 24 months of operation. In harsh chemical or abrasive service, life may be 3 to 9 months. Proper installation and break-in are critical to achieving maximum lifespan.
Q: Does the packing require a break-in period, and why?
A: Yes, a controlled break-in period is essential. It allows the packing to gradually conform to the micro-imperfections of the shaft surface, establishing an optimal seal with minimal friction. It also enables the graphite to form a thin, lubricating transfer film on the shaft. Skipping this step or over-tightening initially can cause immediate overheating, glazing of the packing surface, and rapid shaft wear.
Q: Can this packing be used on mixers with significant shaft runout or eccentricity?
A: While Kaxite Sealing's Graphite PTFE Packing is resilient and forgiving, excessive shaft runout (typically > 0.005 inches or 0.127 mm TIR) will drastically shorten its life and cause excessive leakage. It is always recommended to repair or replace worn shafts and ensure proper alignment before installing any new packing to guarantee performance and longevity.
