PTFE Sealing Strips are high-performance sealing elements

PTFE Sealing Strips are high-performance sealing elements made from polytetrafluoroethylene (PTFE). Their most significant feature is their ability to achieve reliable long-term sealing under extreme operating conditions without additional lubrication, leveraging their excellent chemical inertness, wide temperature range, and low-friction properties.

Chemical Stability 

· Performance: Inert to almost all strong acids, strong alkalis, organic solvents, and oxidizing agents, with exceptional chemical stability.  

· Application Scenarios: Suitable for a wide range of media with pH values of 0–14, excluding a few exceptions such as molten alkali metals and high-temperature fluorine gas.

Temperature Resistance 

· Performance: Extremely wide operating range. Standard models typically operate from -250°C to +280°C, while some variants can withstand temperatures as low as -268°C and as high as +316°C.  

· Application Scenarios: Suitable for applications ranging from ultra-low-temperature cryogenic environments to high-temperature processes.

Friction and Mechanical Characteristics  

· Performance: Extremely low coefficient of friction (0.04–0.1), excellent self-lubrication, and non-stick properties. Soft texture with high compressibility, capable of filling irregular surfaces.  

· Note: Pure PTFE is prone to "cold flow" (creep), meaning it may deform slowly under sustained pressure.

Electrical Performance and Safety  

· Performance:An excellent electrical insulator.  

· Application Scenarios: Suitable for high-cleanliness environments and the food/pharmaceutical industries (meets FDA standards).

 Main Application Areas  

It is specifically designed to address sealing challenges with stringent requirements for corrosion resistance, temperature range, cleanliness, and maintenance-free operation:  

· Highly Corrosive Chemical and Pharmaceutical Applications: Flange sealing for reactors, pipelines, pumps, and valves, resistant to acids, alkalis, and solvents.  

· Extreme Temperature Equipment: Cryogenic equipment (e.g., LNG), high-temperature steam systems, and high-purity equipment in semiconductor manufacturing.  

· High-Cleanliness and Food/Pharmaceutical Applications: Meets sanitary standards for sealing in food and pharmaceutical processing and packaging equipment.  

· Oil-Free Lubrication and Dry-Running Machinery: Piston rods, face seals in compressors (e.g., scroll compressors), vacuum pumps, and oil-free cylinders, enabling maintenance-free operation.  

· Large or Irregular Equipment Sealing: On-site fabrication of sealing rings in any size for large storage tanks or irregular flanges, reducing the precision requirements for sealing surfaces.

 Comparative Advantages  

Compared to common rubber sealing strips (e.g., nitrile rubber, fluororubber) and polyurethane (PU) sealing strips, its characteristics are distinct:

Core Advantages 

1. Unparalleled Comprehensive Stability: Overwhelming advantages in corrosion resistance, temperature range, and anti-aging properties, resulting in an exceptionally long service life.  

2. True Self-Lubrication and Low Friction: Coefficient of friction is significantly lower than other materials, enabling dry operation, energy savings, and maintenance-free performance. Ideal for precision or high-speed motion sealing.  

3. High Cleanliness and Anti-Stick Properties: Does not contaminate media, with a non-stick surface that is easy to clean.  

4. Flexible and Economical Installation: Expandable sealing tapes can be cut and applied on-site to create sealing rings of any size, offering high material utilization, especially suitable for large or non-standard flanges.

In simple terms: It is the top choice for complex conditions involving corrosion, high temperatures, cleanliness, and oil-free operation.

 Key Usage Considerations  

1. Primary Principle: Select Based on Operating Conditions  

   · Static Sealing:For flange surfaces, expandable PTFE sealing tape can be used.  

   · Dynamic Sealing: For reciprocating or rotational motion (e.g., piston rods, shaft seals), pre-formed sealing strips made of filler-modified PTFE (e.g., containing glass fiber, bronze, etc.) must be used, along with spring compensation structures.  

   · Decision Basis: Choose based on the medium, temperature, pressure (especially pressure cycling frequency), and motion type.  

2. Standardized Installation and Operation  

   · Sealing Surface Preparation: Ensure installation surfaces are clean, dry, and free from oil stains and residual old sealing materials.  

   · Correct Installation of Sealing Tape: When applying expandable PTFE tape, the ends must overlap at a bolt (parallel overlap for grooved flanges), with sufficient overlap length. This is critical to prevent leakage.  

   · Even and Moderate Tightening: Use a torque wrench to tighten bolts evenly in a diagonal sequence to the specified value. Over-tightening can accelerate "cold flow," leading to failure.  

   · Avoid Dry Friction at Start-Up: For dynamic seals, even though the material is self-lubricating, adding a small amount of lubricant during the initial phase is recommended to extend service life.  

3. Clarify Prohibitions and Maintenance  

   · Avoid contact with a few media such as molten alkali metals and high-temperature fluorine gas.  

   · Perform regular inspections, especially after the system's initial heating and pressurization, requiring re-tightening while hot. 

   · Dynamic seals should be inspected periodically for wear and the elasticity of compensation springs.

In summary, PTFE sealing strips are the "special forces" for tackling sealing challenges in extreme operating conditions. The key to their successful application lies in accurately selecting the type (pure PTFE vs. filler-modified PTFE) based on the specific requirements of static or dynamic sealing and strictly adhering to installation standards.