Selection of Cap Seals

When many customers seek sealing solutions, we often recommend the Cap Seal, also known as the Spring Energized Seal. Although its price is higher than that of conventional seals, its applicability and functional performance are nearly impeccable, offering outstanding overall performance. Below is a brief introduction to the Cap Seal.

Cap Seals can be primarily classified by application type into the following categories:
- Rod Seal
- Piston Seal
- Rod and Piston Universal Seal
- Face Seal
- Rotary Seal

Common internal spring energizer configurations include O-springs, V-springs, and slant coil springs.

In terms of materials, the sealing element of a Cap Seal is typically made of polytetrafluoroethylene (PTFE) as a base, with various reinforcing materials added, such as carbon fiber, glass fiber, molybdenum disulfide, or graphite. Interestingly, while copper powder is commonly used in other PTFE-based seals like Turcon® seals and Glyd rings®, it is relatively less common in Cap Seals.

In addition to PTFE, Cap Seals can also be manufactured using other high-performance materials, such as:
- Ultra-high molecular weight polyethylene (UHMW-PE/UPE)
- Modified PTFE
- Polychlorotrifluoroethylene (PCTFE)
- Polyether ether ketone (PEEK)

The internal spring is predominantly made of 316 stainless steel. Depending on the operating conditions, 304 or 301 stainless steel, as well as Inconel 718 or Elgiloy® specialty alloys, may also be used.

Whether selecting the material for the sealing element or the spring, our recommendations are tailored to the customer's specific operating conditions—such as the media, pressure, temperature, and motion type.

If you are facing sealing leakage or any other challenging application issues, please feel free to contact our team in Foshan. We are here to provide you with professional and reliable sealing solutions.