About Industrial Seals

Seals and gaskets prevent leaks and create a barrier against contaminants. While there is some overlap between the two, seals are generally used between stationary and moving parts, such as a pump or shaft. Gaskets are more common between two flat parts that do not move such as an engine head gasket. They are also used to seal gaps between sections of pipe, or to seal off valves.

In any application, seals and gaskets must be designed to perform as intended regardless of abrasion, vibration, compression, or temperature extremes. For this reason, they come in many configurations and materials. Seals and gaskets may be flat rings or other closed flat shapes cut from a sheet or roll of material. They can also be extruded tubes or other profiles that are wrapped around components to form a seal.

At Master Packing and Rubber Company, we supply custom gaskets and seals for the automotive, pump and valve manufacturing, oil and gas, food and beverage, railway, chemical, and other industries. With a wide selection of sheet and roll material, plus in-house rubber molding capabilities, we can create sealing solutions for even the most challenging applications.

What is PTFE Gasket Material?

PTFE (polytetrafluoroethylene) is a synthetic fluoropolymer resin commonly used for flat seals and gaskets and in extrusions. Its properties include:

  • Soft and moldable
  • Hydrophobic
  • Chemically inert
  • Resistant to UV radiation and weathering
  • Long-lasting in most applications
  • Electrically and thermally insulating
  • Low coefficient of friction against other solids (i.e., slides easily)
  • Performs well at temperatures between -350°F and 500°F
  • Good lubrication in dry or wet conditions

PTFE gaskets are excellent choices for chemical and petrochemical processing and manufacturing applications because they resist corrosion and chemical damage. They also work well in electrical, food and beverage, and pharmaceutical applications.

Understanding Graphite Seals

Graphite is a natural mineral material, the crystalline form of carbon. It has been used to make gaskets for decades in numerous applications. Properties include:

  • Corrosion resistance
  • Longevity in service and storage
  • Non-porous
  • Good performance between -400°F and 875°F (or temperatures approaching 5000°F in strictly non-oxidizing atmospheres)
  • Ability to mold to surface irregularities under compression
  • Low thermal expansion
  • Low friction surface
  • Good thermal and electrical conductivity

Graphite gasket material is often used for seals in high-pressure and high-temperature applications including steam cycling and exhaust systems, oil and gas equipment, and boilers.

Benefits of PTFE and Graphite Seals

Each of these materials has characteristics that make them suitable for challenging sealing applications. They can also be modified or combined for additional benefits such as:

  • Expanded graphite: Graphite is treated with acids and oxidizing agents to create expanded graphite. The layers become porous and separate, and can then be compressed into a foil that is used in sealing applications in chemical plants. Expanded graphite is also an alternative to non-asbestos filler materials.
  • Expanded PTFE: Made by stretching and forming PTFE into a mesh structure that is very soft and flexible, it can be shaped into tubes and flat gaskets. It is used where a flexible but inert and durable material is needed, including medical and food applications.
  • Graphite filled PTFE: Coating a graphite core with PTFE combines the low coefficient of friction and chemical resistance of PTFE with the strength and stability of graphite. It is used for gaskets, packing, and other sealing applications.

PTFE & Graphite Sealing Solutions by Master Packing and Rubber

Master Packing and Rubber Company is a leader in manufacturing custom industrial sealing products, gaskets, and valve packing material. Our products include lathe-cut gaskets, molded gaskets, gasket material extrusions, spliced gaskets, and valve packing material for sealing liquids, powders, and gases. We offer a selection of high-quality materials including natural rubber, neoprene, EPDM, graphite, PTFE, nitrile, silicone, cork, and metal.

Request a quote to speak with our team about your next industrial seal application.