Spring Energized Teflon PTFE Seals

Spring Energized Teflon (PTFE) Seals are commonly used in Turbomachines where an elastomer (e.g. Buna Rubber Orings) will not meet the temperatures, friction requirements, or chemical resistance of an application. PTFE seals provide the lowest coefficient of friction of all sealing materials. You will see these types of seals in the IGV (inlet guide vane) system of a Boil-off gas Compressor. In this application, the PTFE seal will act as a rod seal under linear and reciprocating motion. Another common application, is the static face seal application where the seal is facing either internal or external pressure. There are many popular PTFE variations such as Flexiseal by Parker, Bal Seal, and Variseal by Trelleborg. 


How Do They Work?

These seals consist of a spring energized "U-shaped" jacket with different profiles and make use of different spring types and materials. These seals can meet temperature ranges from -328°F to 500°F or -200°C to 260°C. These are good candidates for cryogenic applications. 


PTFE behaves as a plastic material, so it does not have the elasticity of an elastomer, such as an Oring. They offer little or no memory after being compressed. Most seals made out of PTFE material needs to utilize an energizing element, which is commonly made of a metal spring. There are different spring materials, but they mainly come standard as 17-7ph stainless steel or a 300 series stainless steel. They can have different jacket materials, but they mainly use virgin PTFE (white color seals).