The uses and types of PTFE gaskets (tetrafluoroethylene gaskets) are as follows:

1. Main uses

1) In the fields of chemical and petrochemical industries

Used in pipelines, reaction vessels, storage tanks and flange connections to prevent leakage of corrosive media such as strong acids, strong bases, and organic solvents.

Typical applications: sealing of media such as sulfuric acid, hydrochloric acid, chlorine gas, etc.

2) In the power and energy industries

Suitable for high-temperature and high-pressure equipment, such as generators, transformers, cable terminations, etc., providing electrical insulation and sealing protection.

Used in nuclear power plants for radiation-resistant and corrosion-resistant sealing scenarios.

3) In the pharmaceutical and food industries

Used in sealing positions with high cleanliness requirements, such as pharmaceutical equipment and food processing machinery's pipeline connections.

Advantages: non-toxic, corrosion-resistant, easy to clean, avoiding product contamination.

4) In mechanical and automotive manufacturing

Used as sealing elements for valves, pumps, compressors, etc., to prevent lubricating oil or cooling fluid leakage.

Applicable to precision mechanical components, such as aircraft engines, high-precision valves, etc.

5) In other fields

High-temperature and high-pressure sealing scenarios in industries such as metallurgy, papermaking, and textiles.

Sealing requirements in marine engineering to resist seawater corrosion.

2. Main types and characteristics

1) Pure PTFE gaskets

Material: 100% polytetrafluoroethylene (PTFE).

Characteristics: resistant to strong acids and strong bases (pH 0-14), wide temperature range (-100°C to 260°C), low friction coefficient, but prone to cold flow deformation.

Form: flat gaskets, V-shaped gaskets, piston rings, etc.

Application: high-cleanliness scenarios such as food and medicine, and sealing of highly corrosive media.

2) Expanded PTFE gaskets (e-PTFE)

Material: PTFE with special process expanded into a porous fiber structure.

Characteristics: excellent flexibility, compression recovery elasticity, strong resistance to creep, suitable for irregular sealing surfaces.

Advantage: combines high sealing performance and temperature resistance (-200°C to 260°C), often used for dynamic sealing.

Application: sealing of rough or worn flange surfaces, such as glass reaction vessels, large-diameter flanges.

3) Filled PTFE gaskets

Material: PTFE with added glass fibers, graphite, carbon fibers, etc., as reinforcing materials.

Characteristics: enhanced mechanical strength, pressure resistance (up to 10 MPa) and wear resistance, but slightly reduced corrosion resistance.

Application: high-pressure, high-temperature (≤200°C) or wear-resistant scenarios, such as chemical equipment, paper machinery bearings.

4) PTFE-coated gaskets

Structure: PTFE coated with non-metallic core (such as asbestos rubber sheet, graphite composite sheet). Category:

V-type (sectional): Economical, suitable for low-pressure pipelines.

L-type (machined): Square cross-section, resistant to medium-high pressure.

U-type (folded type): Large-diameter pipelines (DN200 - 5000mm), with a pressure resistance of 0.6 - 2.5 MPa.

Applications: Pipes for strong corrosive or highly clean media, reaction vessels, valve connections.

5. Modified PTFE gaskets

Material: Enhanced anti-deformation and cold flow performance through chemical modification.

Features: Stable performance under long-term high-pressure conditions, reducing the frequency of flange maintenance.

Applications: Long-term high-pressure conditions in petrochemicals, power, etc.

6. Composite gaskets

Teeth/ribbed composite gaskets: Metal reinforcing layer combined with PTFE, resistant to high pressure and high temperature.

Wound gaskets: Alternating winding of metal strips and PTFE, suitable for extreme conditions (such as petrochemicals). Application: Environments with high temperature, high pressure, vacuum or severe shock and vibration.