PTFE Gasket

Product Overview

PTFE (Polytetrafluoroethylene) gaskets are high-performance sealing elements designed for demanding industrial flange connections. Available in two primary configurations — full-face and ring type (also known as ring type inside bolt circle) — these gaskets provide a reliable, leak-free seal across a wide range of process conditions.

Full-face gaskets extend across the entire flange face, including the bolt holes, and are typically used with flat-face flanges. Ring-type gaskets fit within the bolt circle and are suited for raised-face flanges, offering a more concentrated sealing load.

Material Properties

These gaskets are manufactured from virgin PTFE or filled PTFE compounds. Virgin PTFE offers the purest chemical inertness and is ideal for ultra-clean or highly corrosive environments. Filled PTFE incorporates additives such as glass fibre, carbon, or graphite to enhance mechanical strength, creep resistance, and dimensional stability under load.

PTFE is inherently non-toxic, non-stick, and exhibits extremely low friction, making it suitable for food-grade, pharmaceutical, and chemical processing applications.

Temperature Range

PTFE gaskets perform reliably across an exceptionally wide temperature range, from -200°C to +260°C (-328°F to +500°F). This makes them suitable for cryogenic service as well as high-temperature process lines, providing consistent sealing performance without degradation.

Chemical Compatibility

One of the defining characteristics of PTFE is its near-universal chemical resistance. PTFE gaskets are compatible with virtually all acids (including hydrofluoric and sulphuric acid), caustic alkalis, organic solvents, and oxidising agents. They are resistant to steam, fuels, and most industrial chemicals, making them the preferred choice where other elastomeric or metallic gaskets would fail.

Note: PTFE is not recommended for use with molten alkali metals or elemental fluorine at high temperatures.

Flange Standards

PTFE gaskets are manufactured to comply with internationally recognised flange standards, including ANSI B16.21 (Nonmetallic Flat Gaskets for Pipe Flanges) and DIN 2690 (Flat Gaskets for Flanges). Available in a comprehensive range of nominal pipe sizes (NPS) and pressure classes (PN/Class), ensuring compatibility with standard piping systems worldwide.

Application Guidance

When installing PTFE gaskets, ensure flange faces are clean, flat, and free from damage. Apply bolt torque evenly in a cross-pattern sequence to achieve uniform compression. PTFE is subject to cold flow (creep) under sustained load; re-torquing after initial pressurisation is recommended to maintain sealing integrity.

Typical applications include chemical processing plants, water treatment facilities, pharmaceutical manufacturing, food and beverage pipelines, and offshore or marine environments where corrosion resistance is paramount.