The basics of pneumatic seals

Because of their similar seal profiles, hydraulic and pneumatic seals are frequently confused. The key distinction is that pneumatic seals are actuated by compressed air.

Examples of pneumatic seals

  • Back-up rings: Back-up rings are responsible for supporting O-rings in the event of gap extrusion in static radial sealing.
  • Gaskets: A gasket is a flexible spacer that connects two mating components. Gaskets are commonly used to form a seal. They are constructed from a more flexible material than the components, allowing the gasket to fill any gaps caused by surface imperfections. Gaskets can also be used to prevent component vibration.
  • O-rings: O-rings create a seal by making circular contact between two or more machine components and are some of the most common sealing solutions.
  • Piston seals: Piston seals keep a piston and cylinder bore sealed together.
  • Rotary shaft seals: Rotary shaft seals are used to close and seal the gap between stationary and rotating components.
  • Static seals: This is a seal formed by two stable and immovable components.
  • Symmetrical seals: Symmetrical Seals are seals whose cross section is symmetrical when viewed from a cutaway, i.e., the same on both sides of the centreline. These seals are designed for dynamic linear and reciprocating applications. Because of the symmetrical design, rod and piston applications can be interchanged.
  • U-cups: U-cups is a type of lip seal named after the cross-section’s distinctive “U” shape. They have applications in both dynamic and static environments.
  • V-rings: A V-Ring is a solid rubber seal used on shafts to keep dirt, moisture, and other unwanted material out of an oil seal, housing, or other desired area while keeping lubricants in. It works by stretching over the shaft to form a tight seal while the flexible lip seals lightly against the counterface at a right angle to the shaft.
  • Wear rings: These seals are designed to absorb the rod’s and/or piston’s side load forces and to prevent metal-to-metal contact.
  • Wipers: Wiper seals are essential for applications where equipment must be protected from environmental irregularities like dust, debris, or weather conditions. They are installed in cylinder heads to provide protection.

Single-acting pneumatic seals are used only in one axial direction. However, for a reciprocating motion, double-acting pneumatic seals are used in both directions.

What materials are pneumatic seals manufactured from?

EPDM: Ethylene propylene diene monomer or EPDM is an affordable synthetic rubber that is exceptionally durable and flexible.

Fluorocarbon rubber (FPM): These rubber compounds can withstand high temperatures and harsh chemicals.

Nitrile: Nitrile is a synthetic rubber popular for its oil and chemical resistance. It can also withstand temperatures from -40°C to 108°C.

Polyurethane: Polyurethane is an organic sealant that exhibits hardness, adhesion strength, and flexibility properties.

PTFE: Polytetrafluoroethylene (PTFE) is a synthetic compound that is non-reactive, making it ideal for corrosive chemical applications. In addition, it is self-lubricating and resistant to acids and most chemicals.

Silicone: Silicone is non-reactive, stable, and resistant to extreme temperatures, ozone exposure, UV, and general weathering. It can be used from -60°C to 232°C without becoming brittle in freezing conditions or losing its dimensional tolerance at extremely high temperatures.

Contact Fuzion Trading for details

Fuzion Trading manufactures and stocks a wide range of pneumatic seals for industrial and commercial applications. Contact one of our representatives to learn more about our specialised range of pneumatic seals. Alternatively, you can continue browsing our website for more information.