PTFE Gaskets Frequently Asked Questions
Find answers to the most common questions about PTFE gaskets, their applications, and selection criteria for industrial sealing.
What is a PTFE gasket and what are its main advantages?
A PTFE (Polytetrafluoroethylene) gasket is a sealing component made from PTFE material, known for its exceptional chemical resistance, wide temperature range (-200°C to +260°C), low friction coefficient, and non-stick properties. PTFE gaskets are ideal for applications involving aggressive chemicals, high-purity requirements, and food-grade processing.
What is the difference between virgin PTFE and filled PTFE gaskets?
Virgin PTFE gaskets are made from pure PTFE resin and offer the best chemical resistance. Filled PTFE gaskets contain additives like glass fiber, carbon, graphite, or bronze to enhance specific properties such as compressive strength, wear resistance, thermal conductivity, and dimensional stability. Glass-filled PTFE improves creep resistance, carbon-filled PTFE offers better thermal conductivity, and bronze-filled PTFE provides excellent wear resistance.
What temperature and pressure can PTFE gaskets withstand?
Standard PTFE gaskets can operate in temperatures from -200°C to +260°C (-328°F to +500°F). Pressure ratings depend on gasket design and thickness, typically up to 50 bar (725 psi) for standard sheet gaskets. Filled PTFE gaskets may have slightly different temperature limits depending on the filler material used.
How do I choose the right PTFE gasket thickness?
Gasket thickness selection depends on flange surface finish, bolt load, and operating conditions. Thinner gaskets (1.5mm) provide better blowout resistance and lower leakage rates for smooth flange surfaces. Thicker gaskets (3.0mm) accommodate rougher flange finishes and greater irregularities. For most standard applications, 2.0mm thickness offers a good balance of conformability and performance.
Can PTFE gaskets be used in food and pharmaceutical applications?
Yes, virgin PTFE gaskets are FDA-compliant and suitable for food processing, pharmaceutical, and medical applications. PTFE is non-toxic, non-contaminating, and resistant to cleaning agents and sterilization processes. Always specify FDA-grade PTFE for these applications.
What is the shelf life of PTFE gaskets?
PTFE gaskets have an virtually unlimited shelf life when stored properly. Unlike rubber gaskets, PTFE does not age, oxidize, or degrade over time. Store gaskets flat in a cool, dry environment away from direct sunlight and mechanical stress to maintain dimensional stability.