■ Coated O-ring
Coated O-ring combines the rubber elasticity and airtightness with the chemical resistance of Teflon, and it consists of built-in silicone or FKM and thin coating of Teflon FEP or Teflon PFA, which has excellent sealing performance after combing with Teflon O-ring. The O-ring made of general rubber will be easy to wear and has poor chemical and gas permeability resistance (except for FFKM), while the Teflon O-ring of high hardness has good compression resistance but poor elasticity. Coated Teflon FEP/Teflon PFA O-ring has good solvent expansion resistance and chemical stability (except for erosion by metals, fluorine and halides at high temperature), and the part of O-ring next to the rubber has good elasticity. Teflon FEP/ Teflon PFA has very small frication coefficient (0.1~0.2) and excellent gas permeability resistance, which make the coated O-ring applicable to severe environment.
The seamless, dense and uniform Teflon FEP/Teflon PFA coating and the rubber core make the coated O-ring maintain consistent sealing performance. The elasticity and compression set at each point of O-ring are uniform, and it can be re-installed and re-used under sustained pressure. With the increase of medium pressure, the overall O-ring will be compressed, and the coated O-ring is just like a kind of high viscosity liquid that transmits the pressure acting on it to all directions without attenuation.
The outer coating of Teflon FEP makes the coated O-ring have good resistance to hardening and brittleness, meanwhile the inner core made of silicone or FKM makes the sealing ring be able to maintain good elasticity at the temperature up to 200℃. Test the KTseal FFKM O-ring, FKM O-ring and coated O-ring having FEP/PFA coating in the compression device to compare their sealing performance, with results as shown in the figure. The test results indicate that the coated O-ring combining the physical properties of silicone or FKM and the chemical properties of Teflon FEP/ Teflon PFA will ensure both the rubber performance and good compression resistance.
The coated O-ring shall be manufactured according to strict quality control requirements, and the rubber core shall be wrapped by Teflon FEP polymer completely by virtue of a special technique, so as to ensure the required standard tolerance of such O-ring. All used data indicates that we make an reliable quality commitment to coated O-ring products, which is based on performance testing and strict quality control to ensure customer satisfaction and safety use of this product. In a certain way, the coated O-ring and O-ring made of any other rubbers or pure Teflon have incomparable sealing performance and service life, especially in harsh medium.
■ Main advantages:
1. Outstanding chemical resistance, almost applicable to all chemical media
2. Excellent corrosion resistance
3. Wide applicable temperature
4. Good compression resistance
5. Friction resistance
6. Good solvent expansion resistance
7. High pressure resistance
8. Excellent sealing durability, long service life
2. Reaction container
3. Mechanical seal
5. Pressure vessel
6. Heat exchanger
8. Pipeline flange
9. Gas compressor
■ Main advantages:
1. Chemical industry
2. Aircraft industry
3. Pharmacy industry
4. Transportation of petroleum and chemicals
5. Rubber industry
6. Refrigerating engineering
7. Food processing industry
8. Dye manufacture
9. Paint spraying
12. Civil industry
KTseal focuses on high-performance materials and finished products, the coated O-rings of AS 568A, P, G, V and other series and dimensions are customizable, and the inner core of coated O-ring can be made of either silicone or FKM.
Teflon FEP and Teflon PFA are essentially similar, with the latter has better resistance to high temperature.
■ Range of applicable temperature:
Teflon FEP shell: -60℃ ~ 200℃, short-time use at temperature up to 240℃