Rubber O-rings are prone to wear, have poor chemical corrosion resistance, and have low gas permeability. Pure Teflon O-rings have higher hardness and can resist compression but have poor elasticity.
The outer Teflon FEP/Teflon PFA O-ring has good resistance to swelling and chemical stability (except when exposed to alkali metals, fluorine, and some halides at high temperatures) and exhibits good elasticity near the rubber O-ring. The friction coefficient of Teflon FEP/Teflon PFA is very low (only 0.1 to 0.2), and it has excellent gas permeability, making the sealing ring truly applicable in harsh environments.
Function
The seamless and dense surface of the Teflon FEP/Teflon PFA outer layer combined with the rubber inner core ensures consistent sealing throughout the O-ring. The elasticity and compression at all points on the sealing ring are uniform, allowing for repeated installation and use even under sustained pressure.
As the pressure of the medium increases, the entire sealing ring is compressed. The sealing ring acts like a high-viscosity liquid, transmitting the pressure applied to it in all directions without reduction.
Compressibility
The presence of the Teflon FEP outer layer gives the product good resistance to hardening and brittleness, while the silicone or Viton rubber inner core allows the sealing ring to maintain good elasticity even at high temperatures of 205°C.
The manufacturing of this type of sealing ring requires strict quality control, using a special process to ensure that the Teflon FEP polymer completely envelops the rubber inner core and guarantees that this O-ring meets the required standard tolerances.
Compared to any other rubber or pure Teflon O-rings, the coated O-ring offers unparalleled sealing performance and longevity, especially in harsh media conditions.
Main advantages: 1. Outstanding chemical resistance, suitable for almost all chemical media
2. Excellent corrosion resistance
3. Wide temperature range
4. Good compressibility
5. Friction resistance
6. Good resistance to swelling
7. High pressure resistance
8. Excellent sealing durability and long service life.
Applications: 1. Pumps and valves
2. Reaction vessels
3. Mechanical seals
4. Filters
5. Pressure vessels
6. Heat exchangers
7. Boilers
8. Pipeline flanges
9. Gas compressors
Industries of application
1. Chemical processes
2. Aircraft manufacturing
3. Pharmaceutical industry
4. Transportation of oil and chemicals
5. Refining
6. Film industry
7. Refrigeration engineering
8. Food processing industry
9. Paper industry
10. Dye manufacturing
11. Paint spraying
Material: Teflon FEP and Teflon PFA are essentially very similar, but Teflon PFA has better high-temperature resistance than Teflon FEP.
Temperature range
Teflon FEP outer layer: -60℃ to 205℃, can be used at high temperatures of 260℃ for a short time
Teflon PFA outer layer: -60℃ to 260℃, can be used at high temperatures of 300℃ for a short time
Hardness
The average hardness of the coated O-rings of different materials is:
Solid silicone rubber: 80-85
Solid Viton rubber: 80-85
Hollow silicone rubber: 75-80
