Aramid fiber packing is a high-performance sealing material made from synthetic aramid fibers, known for their exceptional strength, thermal stability, and chemical resistance. This type of packing is engineered to create effective seals in demanding industrial applications, including pumps, valves, mixers, and other rotary or reciprocating equipment. The unique molecular structure of aramid fibers provides a combination of properties not found in many other packing materials, making it a preferred choice for sealing under high pressures, temperatures, and in aggressive chemical environments. Its versatility and durability help reduce maintenance costs and extend equipment life.
Our aramid fiber packing is available in various grades and constructions to meet specific application requirements. Below are the standard parameters for our product line.
| Parameter | Description | Typical Values |
|---|---|---|
| Material Composition | Primary fiber type and additional components | Para-aramid fibers (e.g., Kevlar®-type), impregnated with PTFE or graphite lubricants |
| Temperature Range | Continuous and peak operating temperatures | -100°C to 300°C (-148°F to 572°F) continuous; up to 350°C (662°F) intermittent |
| pH Range | Compatibility with acidic and alkaline environments | 2 - 12 |
| Density | Mass per unit volume | 1.44 g/cm³ |
| Tensile Strength | Resistance to breaking under tension | > 3000 MPa |
| Thermal Conductivity | Ability to conduct heat | 0.04 - 0.05 W/m·K |
| Compression Set | Permanent deformation under load | < 10% |
| Available Sizes | Standard cross-sectional dimensions and lengths | 1/4", 3/8", 1/2", 5/8", 3/4", 1" and custom sizes; coils or spools |
| Colors | Standard color coding for identification | Yellow, White, or custom colors |
The following table outlines the resistance of aramid fiber packing to various common chemicals. Ratings are based on standard immersion tests.
| Chemical | Resistance Rating | Notes |
|---|---|---|
| Water, Sea Water | Excellent | No significant degradation |
| Mineral Oils | Excellent | Highly resistant |
| Dilute Acids (e.g., Sulfuric 10%) | Good | Minor swelling possible; check concentration limits |
| Dilute Alkalis (e.g., Sodium Hydroxide 10%) | Good | Stable under moderate conditions |
| Organic Solvents (e.g., Acetone, Toluene) | Excellent | No chemical attack |
| Strong Oxidizing Agents (e.g., Bleach) | Fair to Poor | Not recommended; can cause degradation |
| Steam | Excellent | Suitable for saturated and superheated steam |
Proper installation is critical for optimal performance. Follow these steps for best results:
What is the maximum temperature aramid fiber packing can handle?
Aramid fiber packing can typically withstand continuous temperatures up to 300°C (572°F). For short-term or intermittent service, it may handle peaks up to 350°C (662°F), but prolonged exposure above the continuous limit can degrade the fibers and reduce sealing effectiveness. Always check the specific product datasheet for exact temperature ratings.
Is aramid fiber packing suitable for food-grade applications?
Standard aramid fiber packing is not inherently food-grade. However, versions are available with FDA-compliant lubricants and treatments for use in food and beverage processing. It is essential to verify certifications and material safety data sheets to ensure compliance with relevant regulations like FDA or EU standards.
How does aramid fiber packing compare to graphite packing?
Aramid fiber packing offers higher tensile strength and better resistance to abrasion and mechanical wear compared to pure graphite packing. Graphite packing generally has superior thermal conductivity and can handle higher temperatures (often above 500°C), but it is more brittle and less resistant to certain chemicals. The choice depends on the specific application requirements, such as temperature, pressure, and chemical exposure.
Can aramid fiber packing be used in high-speed pumps?
Yes, aramid fiber packing is well-suited for high-speed applications due to its high strength, low friction, and excellent wear resistance. It maintains integrity under dynamic conditions, reducing the risk of failure. Proper installation and lubrication are crucial to prevent overheating and ensure long service life in high-speed equipment.
What are the signs that aramid fiber packing needs replacement?
Common indicators include increased leakage beyond acceptable levels, excessive heat generation at the gland area, visible wear or fraying of the packing, and a noticeable drop in equipment performance or efficiency. Regular inspection and maintenance schedules help identify these signs early, preventing unexpected downtime.
Does aramid fiber packing require run-in or break-in period?
Yes, a run-in period is recommended. After installation, the packing should be allowed to seat and adapt to the sealing surfaces. Gradually tightening the gland and monitoring leakage during initial operation helps achieve optimal performance. This process reduces initial friction, minimizes heat buildup, and extends packing life.
Is aramid fiber packing resistant to UV light and outdoor exposure?
Aramid fibers can degrade when exposed to prolonged ultraviolet (UV) light and outdoor weather conditions. For outdoor applications, it is advisable to use protective covers or shields, or select packing with UV-resistant coatings or jackets to prevent deterioration and maintain performance.
Can aramid fiber packing be used in valves as well as pumps?
Absolutely. Aramid fiber packing is versatile and effective for both rotary equipment like pumps and static or slow-moving applications such as valves. Its flexibility and strength allow it to form a reliable seal in various valve types, including gate, globe, and control valves, under different pressure and temperature conditions.
