PTFE O-ring

PTFE O-ring (commonly known as PTFE O-ring or PTFE O-ring) is a circular seal made of polytetrafluoroethylene (PTFE) material, designed for harsh working conditions such as strong corrosion, extreme temperature, and high cleanliness.

1、 Core performance (advantages)

Good effect, chemical resistance

Almost resistant to all strong acids, strong bases, organic solvents (based on actual reports), and strong oxidants (only a few media such as molten alkali metals and elemental fluorine can corrode).

Wide temperature resistance range

Long term working temperature -200 ℃~+260 ℃, short-term can withstand 300 ℃.

Relatively low friction coefficient

Good self-lubricating properties (dry friction coefficient of 0.05~0.1), non stick, wear-resistant (based on actual reports), and low starting resistance.

High cleanliness and physiological inertness

Toxic detection, no precipitation, FDA compliant, suitable for food, medicine, and semiconductor.

Weather resistance/insulation

Ozone resistance, UV resistance, and aging resistance; Excellent electrical insulation properties.

2、 Main drawbacks (limitations)

Poor elasticity, no rebound (harder than rubber), and significant deformation after prolonged compression.

Cold flow (creep): It is prone to slow plastic flow under long-term high pressure.

Pure PTFE is not suitable for dynamic high-pressure sealing and often needs to be filled with modified or coated with rubber.

3、 Common types

Pure PTFE O-ring: static, corrosion-resistant (based on actual reports), high and low temperature.

Filling modified PTFE: adding glass fiber, carbon fiber, graphite, copper powder, etc. to improve compression resistance, creep resistance, and wear resistance (based on actual reports).

PTFE coated O-ring: inner core rubber (NBR/FKM)+outer layer PTFE, balancing elasticity and corrosion resistance.

4、 Typical applications

Chemical/Petrochemical: Valves, pumps, reactors, pipelines (strongly corrosive media).

Pharmaceutical/Food: Sanitary grade equipment, high-temperature steam cleaning, sterile sealing.

Semiconductors: high-purity chemicals, vacuum equipment, etching machines.

Aerospace: Liquid oxygen/liquid nitrogen, low-temperature fuel systems.

Mechanical/automotive: oil-free lubrication, wear-resistant (based on actual reports), insulated parts.

5、 Key selection points

Static sealing → prioritize pure PTFE or filled PTFE.

Dynamic/reciprocating/rotating → Select filling modified or coated type.

High pressure → use pure PTFE with caution, it is recommended to fill with a retaining ring.

Temperature/medium → Confirm stability at -200~260 ℃ and corresponding medium.