PTFE VS Graphite Packing: What’s The Difference?

SEPCO ML2225 PTFE Packing
SEPCO ML2225 Acrylic Fiber Braided Throughout with PTFE
SEPCO ML 402 Graphite Packing
SEPCO ML402 Braided Acrylic Fiber Braided Throughout a Lubrication/ Graphite Mix

PTFE and Graphite are popular materials used in valve and shaft packing, as well as similar applications. Both are usually found in a braided style, and both have a low coefficient of friction that allows them to be excellent sealants with longer shelf lives. They are both cost-effective, durable, and low maintenance.

Despite all these similarities, PTFE and Graphite are very different types of sealants and often are used for different purposes. The main difference is the material each one is made from. Graphite is a naturally-occurring form of carbon white PTFE, or Polytetrafluoroethylene is a synthetic polymer. These origins cause them to have different properties and different applications.

PTFE Packing

PTFE is a white-colored synthetic polymer that can be lubricated and braided to form a flexible packing with excellent properties. This strong resin is highly resistant to aggressive substances, such as chemicals, acids, gasses, and many more caustic or abrasive substances. It protects shafts from wear and tear and is good insulation in electrical applications. Multi-yarn packings can also be made for increased strength and better lubrication capabilities.

PTFE is a widely-used braided sealant, as it is excellent for a wide range of systems dealing with fuel gasses, mineral and synthetic oils, steam water, effluents, strong chemicals, and many more. PTFE can be used in industrial plants that handle corrosive substances and oxidizers (except molten alkali metals). It’s also widely used in systems that handle other aggressive substances in pharmaceutical, food, aerospace, and electrical markets.

PTFE can also be combined with other materials to improve its properties and performance to meet specific application requirements. For example, multi-yarn PTFE packings can be designed to meet FDA requirements for edible products and pharmaceuticals. Overall, PTFE packing is a versatile and flexible sealant.

Graphite Packing

Graphite is a naturally occurring, inorganic form of pure carbon used to form a black-colored braided sealant. Graphite packings can also be blended with many other materials, including PTFE, for enhanced characteristics. They are good conductors of heat and are suitable for agitators, valves, and shafts that handle chemicals and acids.

Graphite packings are suited to high-pressure applications, faster shaft speeds, and high temperatures, such as steam turbines and high-temperature valves. They are a perfect alternative to asbestos packings, with simple installation and maintenance. Graphite packings offer even more benefits when treated with PTFE, such as preventing color contamination and improved system stability.